1
|
Costilla R, Zeng J, Al Kalaldeh M, Swaminathan M, Gibson JP, Ducrocq V, Hayes BJ. Developing flexible models for genetic evaluations in smallholder crossbred dairy farms. J Dairy Sci 2023; 106:9125-9135. [PMID: 37678792 PMCID: PMC10772325 DOI: 10.3168/jds.2022-23135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2022] [Accepted: 07/07/2023] [Indexed: 09/09/2023]
Abstract
The productivity of smallholder dairy farms is very low in developing countries. Important genetic gains could be realized using genomic selection, but genetic evaluations need to be tailored for lack of pedigree information and very small farm sizes. To accommodate this situation, we propose a flexible Bayesian model for the genetic evaluation of milk yield, which allows us to simultaneously account for nongenetic random effects for farms and varying SNP variance (BayesR model). First, we used simulations based on real genotype data from Indian crossbred dairy cattle to demonstrate that the proposed model can separate the true genetic and nongenetic parameters even for small farm sizes (2 cows on average) although with high standard errors in scenarios with low heritability. The accuracy of genomic genetic evaluation increased until farm size was approximately 5. We then applied the model to real data from 4,655 crossbred cows with 106,109 monthly test day milk records and 689,750 autosomal SNPs. We estimated a heritability of 0.16 (0.04) for milk yield and using cross-validation, a genomic estimated breeding value (GEBV) accuracy of 0.45 and bias (regression of phenotype on GEBV) of 1.04 (0.26). Estimated genetic parameters were very similar using BayesR, BayesC, and genomic BLUP approaches. Candidate genes near the top variants, IMMP2L and ARHGEF2, have been previously associated with milk protein composition, mastitis resistance, and milk cholesterol content. The estimated heritability and GEBV accuracy for milk yield are much lower than those from intensive or pasture-based systems in many countries. Further increases in the number of phenotyped and genotyped animals in farms with at least 2 cows (preferably 3-5, to allow for dropout of cows) are needed to improve the estimation of genetic effects in these smallholder dairy farms.
Collapse
Affiliation(s)
- R Costilla
- AgResearch Limited, Ruakura Research Centre, Hamilton 3214, New Zealand; Centre for Animal Science, Queensland Alliance for Agriculture and Food Innovation, University of Queensland, St. Lucia, QLD 4067, Australia.
| | - J Zeng
- Institute for Molecular Biosciences, University of Queensland, St. Lucia, QLD 4067, Australia
| | - M Al Kalaldeh
- Centre for Genetic Analysis and Applications, School of Environmental and Rural Science, University of New England, Armidale, NSW 2350, Australia
| | - M Swaminathan
- BAIF Development Research Foundation, Pune 412 202, Maharashtra, India
| | - J P Gibson
- Centre for Genetic Analysis and Applications, School of Environmental and Rural Science, University of New England, Armidale, NSW 2350, Australia
| | - V Ducrocq
- Universite Paris-Saclay, INRAE, AgroParisTech, UMR GABI, 78350 Jouy-en-Josas, France
| | - B J Hayes
- Centre for Animal Science, Queensland Alliance for Agriculture and Food Innovation, University of Queensland, St. Lucia, QLD 4067, Australia
| |
Collapse
|
2
|
Clarke S, Geczy R, Balgi A, Park S, Zhao R, Swaminathan M, Tieu R, Hoang N, Webb C, Watt E, Wong M, Fujisawa M, Jain N, Zhang A, Thomas A. Abstract 1785: Multi-step engineering of gene-edited CAR T cells using RNA lipid nanoparticles. Cancer Res 2023. [DOI: 10.1158/1538-7445.am2023-1785] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/07/2023]
Abstract
Abstract
Autologous chimeric antigen receptor (CAR) T therapies utilize patient cells and can be limited by cell quality, and the high manufacturing burden of viral vectors. As such, there is a need for allogeneic, “off-the-shelf” CAR T cells to make these transformative treatments widely available. However, allogeneic therapies require multiple genetic engineering steps to express CAR and to delete proteins responsible for graft-versus-host disease. Messenger RNA (mRNA) is a promising approach for expression of therapeutic proteins and gene editing nucleases. In this work, we demonstrate a new method for multi-step engineering of gene-edited CAR T cells using RNA lipid nanoparticles (LNPs).
LNPs encapsulating Spy-Cas9 mRNA, TCR and CD52 guide RNA (sgRNA), and CAR mRNA were produced using microfluidics. The CAR construct contained an anti-CD19 scFv binding domain and CD3ζ/4-1BB co-stimulatory domains. Microgram quantities of RNA LNPs were produced to optimize LNP packaging, cargo ratios, and sgRNA combinations. Lead candidates were scaled to milligrams. Purified human primary T cells were cultured, activated, and expanded in serum-free media in plates, flasks and bioreactors. CAR+, TCR− or CD52− cells were generated by addition of the corresponding LNP to activated cells. Cytotoxic killing was determined by co-culture assays with leukemia cells. Gene knockout, CAR expression, viability and cell killing were measured using flow-cytometry.
CD19 CAR was selected as a relevant protein for expression, with TCR and CD52 proteins as gene knockout targets. Single-step addition of CAR LNPs to T cells resulted in transfection efficiencies of 95.0 ± 2.1% and high protein expression. Upon TCR or CD52 LNP addition to T cells, the onset of gene editing was within 48 hours, reaching single target knockout efficiencies of 92.3 ± 3.0% (TCR−), and double knockouts (TCR−/CD52−) of 74.5 ± 6.1%. Similar results were obtained when comparing different LNP batch sizes (microgram to milligram RNA) and cell culture vessels (125,000 to 45 million cells), demonstrating scalability of both the LNP production and cell treatment. Cell viabilities above 90% were maintained at all steps and for all RNA LNPs. Finally, as proof-of-concept for multi-step engineering, sequential addition of TCR LNPs and CAR LNPs resulted in simultaneous CAR expression and TCR gene knockout. These “off-the-shelf” gene-edited CAR T cells were functionally equivalent to non-edited cells in a B cell killing assay, efficiently clearing over 80% of leukemia target cells at a 1:1 ratio.
Our findings demonstrate the advantages of LNPs for RNA delivery to T cells. The simple and gentle nature of LNP cell treatment allows for multiple genetic engineering steps for simultaneous expression and deletion of proteins. Furthermore, LNPs can be easily manufactured using microfluidics, enabling small-scale screening of RNA libraries and rapid scale-up of lead candidates for clinical translation.
Citation Format: Samuel Clarke, R Geczy, A Balgi, S Park, R Zhao, M Swaminathan, R Tieu, N Hoang, C Webb, E Watt, M Wong, M Fujisawa, N Jain, Angela Zhang, Anitha Thomas. Multi-step engineering of gene-edited CAR T cells using RNA lipid nanoparticles [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 1785.
Collapse
Affiliation(s)
- Samuel Clarke
- 1Precision NanoSystems ULC, Vancouver, British Columbia, Canada
| | - R Geczy
- 1Precision NanoSystems ULC, Vancouver, British Columbia, Canada
| | - A Balgi
- 1Precision NanoSystems ULC, Vancouver, British Columbia, Canada
| | - S Park
- 1Precision NanoSystems ULC, Vancouver, British Columbia, Canada
| | - R Zhao
- 1Precision NanoSystems ULC, Vancouver, British Columbia, Canada
| | - M Swaminathan
- 1Precision NanoSystems ULC, Vancouver, British Columbia, Canada
| | - R Tieu
- 1Precision NanoSystems ULC, Vancouver, British Columbia, Canada
| | - N Hoang
- 1Precision NanoSystems ULC, Vancouver, British Columbia, Canada
| | - C Webb
- 1Precision NanoSystems ULC, Vancouver, British Columbia, Canada
| | - E Watt
- 1Precision NanoSystems ULC, Vancouver, British Columbia, Canada
| | - M Wong
- 1Precision NanoSystems ULC, Vancouver, British Columbia, Canada
| | - M Fujisawa
- 1Precision NanoSystems ULC, Vancouver, British Columbia, Canada
| | - N Jain
- 1Precision NanoSystems ULC, Vancouver, British Columbia, Canada
| | - Angela Zhang
- 1Precision NanoSystems ULC, Vancouver, British Columbia, Canada
| | - Anitha Thomas
- 1Precision NanoSystems ULC, Vancouver, British Columbia, Canada
| |
Collapse
|
3
|
Swaminathan M, Angelakas A, Baxter M, Cotton J, Dobeson C, Feeney L, Gault A, Hughes D, Jones C, Lee R, Mughal S, Parikh S, Pritchard M, Rodgers L, Rowe M, Salawu A, Shotton R, Tinsley N, Tivey A, Olsson-Brown A. 241P Treatment and outcomes of patients with gastrointestinal toxicity following immunotherapy: A large multi-center retrospective study in the United Kingdom by the National Oncology Trainees Collaborative for Healthcare Research (NOTCH). Immuno-Oncology and Technology 2022. [DOI: 10.1016/j.iotech.2022.100230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
4
|
Usha Mary T, Swaminathan M. Enhanced biodegradation of thiocyanate by immobilized Bacillus brevis. J INDIAN CHEM SOC 2022. [DOI: 10.1016/j.jics.2022.100588] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
5
|
Raja A, Son N, Swaminathan M, Kang M. Facile synthesis of sphere-like structured ZnIn 2S 4-rGO-CuInS 2 ternary heterojunction catalyst for efficient visible-active photocatalytic hydrogen evolution. J Colloid Interface Sci 2021; 602:669-679. [PMID: 34153706 DOI: 10.1016/j.jcis.2021.06.034] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2021] [Revised: 06/04/2021] [Accepted: 06/06/2021] [Indexed: 11/28/2022]
Abstract
Photocatalysis is a promising approach for generating hydrogen, an eco-friendly and cost-effective fuel. It is hypothesized that the ternary catalyst ZnIn2S4-rGO-CuInS2, prepared by ultrasonication method, should be effective for optimized photocatalytic hydrogen generation in a Na2S/Na2SO3-water mixture. The as-synthesized catalyst was characterized using various surface analytical and optical techniques. Field-emission scanning electron microscopy and high-resolution transmission electron microscopy analyses revealed that marigold-like structured ZnIn2S4 and layer-structured CuInS2 were dispersed on the reduced graphene oxide sheets. The ternary ZnIn2S4-rGO-CuInS2 system showed enhanced photocatalytic H2 production compared to pure ZnIn2S4, CuInS2, ZnIn2S4-rGO, CuInS2-rGO, and ZnIn2S4-CuInS2 catalysts under visible light illumination. The fabricated ZnIn2S4-rGO-CuInS2 catalyst afforded hydrogen generation of 2531 μmol/g after 5 h. The enhanced performance of the ZnIn2S4-rGO-CuInS2 catalyst originates from the synergetic effect with rGO as the electron transfer medium, and is confirmed by photocurrent density and photoluminescence measurements that indicate reduced recombination between the excited electron and hole pairs, and fast electron transfer in the ternary composite. The excellent performance of the ZnIn2S4-rGO-CuInS2 catalyst for up to three consecutive cycles was demonstrated in cyclic stability tests under visible-light illumination.
Collapse
Affiliation(s)
- A Raja
- Department of Chemistry, College of Natural Sciences, Yeungnam University, Gyeongsan, Gyeongbuk 38541, Republic of Korea.
| | - Namgyu Son
- Department of Chemistry, College of Natural Sciences, Yeungnam University, Gyeongsan, Gyeongbuk 38541, Republic of Korea
| | - M Swaminathan
- Department of Chemistry, Kalasalingam University, Tamil Nadu, India
| | - Misook Kang
- Department of Chemistry, College of Natural Sciences, Yeungnam University, Gyeongsan, Gyeongbuk 38541, Republic of Korea.
| |
Collapse
|
6
|
Swaminathan M, Shanthi M. Photocatalytic Degradation of Naphthol Green B Dye Using Coupled CdS-ZnMoO₄ in UV-A Light Irradiation. J Nanosci Nanotechnol 2021; 21:1526-1536. [PMID: 33404416 DOI: 10.1166/jnn.2021.18984] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
At present, nanotechnology field development makes a major role in photocatalysis. CdS-ZnMoO₄ (36.6 wt%) coupled nanophotocatalyst is synthesized using facile hydrothermal method. The CdSZnMoO₄ catalyst shows superior photocatalytic activity in the Naphthol Green B (NGB) dye degradation in UV-A (365 nm) light irradiation. XRD analysis reveals the monoclinic structure of ZnMoO₄, cubic structure of CdS. PL shows lesser the recombination (e--h+) rate of electron-hole pair formation. UV-Vis-DRS reveals an increase in absorption in entire visible region while loading with CdS. SEM images indicate that CdS-ZnMoO₄ has nanofibrous structure. EDS reveal that Cd and S are present on the ZnMoO₄ surface. ECM indicates the division of homogeneity in elements. SAED pattern of HR-TEM images proved high crystalline properties of the catalyst. XPS reveals the different oxidation states and term-symbols of Cd, S, Zn, Mo and O in this catalyst with corresponding binding energies. CdS-ZnMoO₄ (18.5 m²g-1) has a higher surface area compared to ZnMoO₄ (10.8 m²g-1). Current densities obtained from CV reveals the higher cyclic movement of electrons (electrochemical activity) of CdS-ZnMoO₄. An effective parameters for photodegradability of NGB dye by CdS-ZnMoO₄ was analyzed.
Collapse
Affiliation(s)
- M Swaminathan
- Nanomaterials Laboratory, Department of Chemistry, Kalasalingam Academy of Research and Education, Krishnankoil 626126, India
| | - M Shanthi
- Department of Chemistry, Annamalai University, Annamalainagar 608002, Tamilnadu, India
| |
Collapse
|
7
|
Raja A, Rajasekaran P, Selvakumar K, Arunpandian M, Kaviyarasu K, Asath Bahadur S, Swaminathan M. Visible active reduced graphene oxide-BiVO4-ZnO ternary photocatalyst for efficient removal of ciprofloxacin. Sep Purif Technol 2020. [DOI: 10.1016/j.seppur.2019.115996] [Citation(s) in RCA: 108] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
|
8
|
Suppuraj P, Thirumalai K, Parthiban S, Swaminathan M, Muthuvel I. Novel Ag-TiO₂/ZnFe₂O₄ Nanocomposites for Effective Photocatalytic, Electrocatalytic and Cytotoxicity Applications. J Nanosci Nanotechnol 2020; 20:709-718. [PMID: 31383066 DOI: 10.1166/jnn.2020.16893] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
We report the preparation and characterization of a new heterostructured Ag-TiO₂/ZnFe₂O₄ (ATZ) nanocomposite. X-ray diffraction (XRD) reveals the presence of spinel type ZnFe₂O₄ and anatase TiO₂. Scanning electron microscope (SEM) images of ATZ nanocomposites show that Ag nanoparticles are successfully loaded on the composite Ag-TiO₂ and is uniformly distributed on surface of ZnFe₂O₄ forming a nanocomposite with an approximate particle size of 44.8 nm. High-resolution transmission electron microscope (HR-TEM) analysis clearly indicates the particles with spherical and hexagonal structure and sizes of most of the particles are below 50 nm. Ultra violet-visible diffuse reflectance spectra (UV-vis-DRS) show that Ag-TiO₂/ZnFe₂O₄ has increased visible absorption than TiO₂. Photoluminescence (PL) spectra shows that the intensity of ATZ is low relative to prepared TiO₂. The photocatalytic degradation of Reactive Yellow 86 (RY 86) dye was studied. Based on the band gap energies of TiO₂ and ZnFe₂O₄, a mechanism of degradation is given. Photocatalytic activity results suggest that as-prepared ATZ shows higher photodegradation efficiency than pure TiO₂. The main reactive oxidative species involved in the degradation and stability of photocatalyst were also investigated. ATZ shows higher electrocatalytic activity than TiO₂ for methanol electrooxidation. The cytotoxicity of ATZ was analysed. Multifunctionality of ATZ makes it useful for environmental and biomedical applications.
Collapse
Affiliation(s)
- P Suppuraj
- Advanced Photocatalysis Laboratory, Department of Chemistry, Annamalai University, Annamalainagar 608002, Tamilnadu, India
| | - K Thirumalai
- Advanced Photocatalysis Laboratory, Department of Chemistry, Annamalai University, Annamalainagar 608002, Tamilnadu, India
| | - S Parthiban
- Advanced Photocatalysis Laboratory, Department of Chemistry, Annamalai University, Annamalainagar 608002, Tamilnadu, India
| | - M Swaminathan
- Nanomaterials Laboratory, Department of Chemistry, Kalasalingam Academy of Research and Education, Krishnankoil 626126, India
| | - I Muthuvel
- Advanced Photocatalysis Laboratory, Department of Chemistry, Annamalai University, Annamalainagar 608002, Tamilnadu, India
| |
Collapse
|
9
|
Ezhilmathi P, Thirumalai K, Swaminathan M, Krishnasamy K. One-Pot Synthesis of Tetra Substituted Imidazoles Catalyzed by Fly Ash Supported Bi2O3-ZnO. J Nanosci Nanotechnol 2019; 19:8163-8171. [PMID: 31196340 DOI: 10.1166/jnn.2019.16863] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
A simple and efficient one pot synthesis of 1,2,4,5-tetra substituted imidazoles is achieved by condensation-cyclization reaction of benzil, aromatic aldehyde, 2-amino ethyl pyrrolidine, ammonium acetate using fly ash loaded Bi₂O₃-ZnO. Different substituted aldehydes have been used in this reaction. The process is operationally simple, environmentally safe and has magnificent yield. Furthermore this catalyst can be recycled at least four times without any loss of activity.
Collapse
Affiliation(s)
- P Ezhilmathi
- Department of Chemistry, Annamalai University, Annamalainagar 608002, Tamilnadu, India
| | - K Thirumalai
- Department of Chemistry, Annamalai University, Annamalainagar 608002, Tamilnadu, India
| | - M Swaminathan
- Department of Chemistry, Annamalai University, Annamalainagar 608002, Tamilnadu, India
| | - K Krishnasamy
- Department of Chemistry, Annamalai University, Annamalainagar 608002, Tamilnadu, India
| |
Collapse
|
10
|
Swaminathan M, Fung C, Finkelstein DI, Bornstein JC, Foong JPP. α-Synuclein Regulates Development and Function of Cholinergic Enteric Neurons in the Mouse Colon. Neuroscience 2019; 423:76-85. [PMID: 31705886 DOI: 10.1016/j.neuroscience.2019.10.029] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 10/15/2019] [Accepted: 10/16/2019] [Indexed: 02/07/2023]
Abstract
Alpha-Synuclein (α-Syn) is expressed in the central nervous system and the nervous system of the gut (enteric nervous system, ENS), and is well known to be the major constituent of Lewy bodies which are the hallmark of Parkinson's disease. Gastrointestinal disorders frequently manifest several years before motor deficits develop in Parkinson's patients. Despite extensive research on pathological rodent models, the physiological role of α-Syn in the normal ENS is unclear hampering analysis of its neuropathology. We compared the ENS in colons of α-Syn-knockout (α-Syn KO) and wild-type mice using immunohistochemistry and calcium-imaging of responses to synaptic input. We found that α-Syn is predominantly expressed in cholinergic varicosities, which contain vesicular acetylcholine transporter. α-Syn KO mice had higher enteric neuron density and a larger proportion of cholinergic neurons, notably those containing calretinin, demonstrating a role for α-Syn in regulating development of these neurons. Moreover, α-Syn deletion enhanced the amplitude of synaptically activated [Ca2+]i transients that are primarily mediated by acetylcholine activating nicotinic receptors suggesting that α-Syn modulates the availability of acetylcholine in enteric nerve terminals.
Collapse
Affiliation(s)
- M Swaminathan
- Department of Physiology, The University of Melbourne, Parkville, VIC, Australia
| | - C Fung
- Department of Physiology, The University of Melbourne, Parkville, VIC, Australia
| | - D I Finkelstein
- The Florey Institute of Neuroscience and Mental Health, Kenneth Myer Building, The University of Melbourne, Parkville, VIC, Australia
| | - J C Bornstein
- Department of Physiology, The University of Melbourne, Parkville, VIC, Australia
| | - J P P Foong
- Department of Physiology, The University of Melbourne, Parkville, VIC, Australia.
| |
Collapse
|
11
|
Thiruppathi M, Vahini M, Devendran P, Arunpandian M, Selvakumar K, Ramalingan C, Swaminathan M, Nagarajan ER. CuWO₄ Nanoparticles: Investigation of Dielectric, Electrochemical Behaviour and Photodegradation of Pharmaceutical Waste. J Nanosci Nanotechnol 2019; 19:7026-7034. [PMID: 31039855 DOI: 10.1166/jnn.2019.16601] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The hydrothermally synthesized CuWO₄ nanoparticles (NPs) were characterized with different analysis such as X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), High Resolution Transmission Electron Microscopy (HRTEM), Energy Dispersive X-ray Spectroscopy (EDX), Cyclic Voltammetry (CV), UV-Visible and Photoluminescence (PL) analysis. The prepared CuWO₄ NPs were examined with Electrochemical Impedance Spectroscopy (EIS). SEM images show that CuWO₄ NPs are highly spherical shaped morphology and porous in nature. The optical band gap of prepared CuWO₄ NPs is found to be 2.12 eV. Photodegradation of diclofenac sodium (DFS) (medical waste) in the aqueous medium with CuWO₄ NPs under visible light irradiation shows 98% degradation. The CuWO₄ NPs was stable up to 5th cycle it can be used as a reusable photocatalyst for the DFS degradation. The electrical conductivity and dielectric properties of the CuWO₄ NPs at room temperature is analyzed by EIS studies. The bulk conductivity value of the prepared nanoparticles is 1.477×10-5 S/cm at room temperature. The conductivity of CuWO₄ NPs is found to be due to electrons movement. The CuWO₄ NPs shows higher photocatalytic and electrocatalytic activity for decomposition of DFS and methanol electro-oxidation in alkaline medium respectively.
Collapse
Affiliation(s)
- M Thiruppathi
- Department of Chemistry, Nanomaterials Laboratory, International Research Centre, Kalasalingam Academy of Research and Education, Krishnankoil 626126, Tamil Nadu, India
| | - M Vahini
- Department of Physics, Multifunctional Materials Laboratory, International Research Centre, Kalasalingam Academy of Research and Education, Krishnankoil 626126, Tamil Nadu, India
| | - P Devendran
- Department of Physics, Multifunctional Materials Laboratory, International Research Centre, Kalasalingam Academy of Research and Education, Krishnankoil 626126, Tamil Nadu, India
| | - M Arunpandian
- Department of Chemistry, Nanomaterials Laboratory, International Research Centre, Kalasalingam Academy of Research and Education, Krishnankoil 626126, Tamil Nadu, India
| | - K Selvakumar
- Department of Chemistry, Nanomaterials Laboratory, International Research Centre, Kalasalingam Academy of Research and Education, Krishnankoil 626126, Tamil Nadu, India
| | - C Ramalingan
- Department of Chemistry, Nanomaterials Laboratory, International Research Centre, Kalasalingam Academy of Research and Education, Krishnankoil 626126, Tamil Nadu, India
| | - M Swaminathan
- Department of Chemistry, Nanomaterials Laboratory, International Research Centre, Kalasalingam Academy of Research and Education, Krishnankoil 626126, Tamil Nadu, India
| | - E R Nagarajan
- Department of Chemistry, Nanomaterials Laboratory, International Research Centre, Kalasalingam Academy of Research and Education, Krishnankoil 626126, Tamil Nadu, India
| |
Collapse
|
12
|
Thirumalai K, Ida G, Selvakumar K, Easwaramoorthy D, Swaminathan M. UV-A Light Driven Activated Charcoal Supported Bi₂O₃-ZnO Nanocomposites; Hydrothermal Synthesis and Their Enhanced Photocatalytic and Self Cleaning Applications. J Nanosci Nanotechnol 2019; 19:5089-5099. [PMID: 30913824 DOI: 10.1166/jnn.2019.16837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
The Activated Charcoal supported Bi₂O₃-ZnO (AC-BZ) nanocomposite is successfully synthesized by simple and efficient hydrothermal followed by thermal decomposition method. The addition of Activated charcoal into the Bi₂O₃-ZnO matrices increases the active sites and shows efficient catalytic activity upon the degradation of azo dyes, Rhodamine-B (Rh-B) and Trypan Blue (TB). Prepared photocatalysts further prove its ability by the way of structure and absorption capacity. For understanding the efficiency of photocatalyst, it was characterized by X-ray diffraction (XRD), Field Emission Scanning Electron Microscopy (FE-SEM), Field Emission Transmission Electron Microscopy (FE-TEM), High Resolution Transmission Electron Microscopy (HR-TEM), Diffused Reflectance Spectroscopy (UV-DRS), Photo Luminescense spectroscopy (PL) and N₂ adsorption- desorption isotherms (BET). The FESEM images of the activated charcoal supported Bi₂O₃-ZnO show a nanocomposite structure and reveal that most of particles have hexagonal and spherical type in nano range. Absorption range and band gap energy were examined by UV-DRS techniques, which indicate the photogenerated electrons and holes are responsible for better photocatalytic activity. The prepared AC-BZ nanocomposite has maximum efficiency at pH 7, and it shows enhanced degradation efficiency up to four cycles which proves reusability of the catalyst. The obtained catalyst shows higher efficiency in self cleaning property by forming maximum degree of contact angle when compared with pure ZnO and Bi₂O₃-ZnO. This work may provide new strategy for eco-friendly and cost effective photocatalysts for various applications.
Collapse
Affiliation(s)
- K Thirumalai
- Photocatalysis Laboratory, Department of Chemistry, Annamalai University, Annamalainagar 608002, Tamilnadu, India
| | - G Ida
- Research and Development Centre, Bharathiar University, Coimbatore 641046, Tamilnadu, India
| | - K Selvakumar
- Nanomaterials Laboratory, Department of Chemistry, International Research Centre, Kalasalingam Academy of Research and Education, Krishnankoil 626126, Tamilnadu, India
| | - D Easwaramoorthy
- Research and Development Centre, Bharathiar University, Coimbatore 641046, Tamilnadu, India
| | - M Swaminathan
- Photocatalysis Laboratory, Department of Chemistry, Annamalai University, Annamalainagar 608002, Tamilnadu, India
| |
Collapse
|
13
|
Raja A, Selvakumar K, Rajasekaran P, Arunpandian M, Ashokkumar S, Kaviyarasu K, Asath Bahadur S, Swaminathan M. Visible active reduced graphene oxide loaded titania for photodecomposition of ciprofloxacin and its antibacterial activity. Colloids Surf A Physicochem Eng Asp 2019. [DOI: 10.1016/j.colsurfa.2018.12.024] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
14
|
Radha N, Swaminathan M. Fluorescence Quenching of 2-amino-7-bromofluorene by Chloromethanes – Static and Dynamic Model for CCl4 Quenching in Polar Solvents. Journal of Chemical Research 2019. [DOI: 10.3184/030823401103168730] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The study of fluorescence quenching of 2-amino-7-bromofluorene (ABF) by chloromethanes (CH2Cl2, CHCl3, CCl4) in various solvents reveals that (i) the quenching constant kq depends on solvent viscosity for CCl4 and on solvent polarity for CH2Cl2 and CHCl3; (ii) the observed positive deviation in methanol and acetonitrile in the Stern–Volmer plot is due to the presence of a static component in quenching; (iii) the fluorescence quenching is mainly due to the formation of a non-emissive charge transfer complex in the excited state.
Collapse
Affiliation(s)
- N. Radha
- Department of Chemistry, Annamalai University, Annamalainagar – 608 002, India
| | - M. Swaminathan
- Department of Chemistry, Annamalai University, Annamalainagar – 608 002, India
| |
Collapse
|
15
|
Suppuraj P, Parthiban S, Swaminathan M, Muthuvel I. Hydrothermal fabrication of ternary NrGO-TiO2/ZnFe2O4 nanocomposites for effective photocatalytic and fuel cell applications. ACTA ACUST UNITED AC 2019. [DOI: 10.1016/j.matpr.2019.04.104] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
16
|
Raja A, Ashokkumar S, Pavithra Marthandam R, Jayachandiran J, Khatiwada CP, Kaviyarasu K, Ganapathi Raman R, Swaminathan M. Eco-friendly preparation of zinc oxide nanoparticles using Tabernaemontana divaricata and its photocatalytic and antimicrobial activity. Journal of Photochemistry and Photobiology B: Biology 2018; 181:53-58. [DOI: 10.1016/j.jphotobiol.2018.02.011] [Citation(s) in RCA: 169] [Impact Index Per Article: 28.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Revised: 02/03/2018] [Accepted: 02/08/2018] [Indexed: 10/18/2022]
|
17
|
Molinari A, Plager D, Merino P, Galan MM, Swaminathan M, Ramasuramanian S, de Faber JTHN. Accessory Extraocular Muscle as a Cause of Restrictive Strabismus. Strabismus 2016; 24:178-183. [DOI: 10.1080/09273972.2016.1242641] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
18
|
Senthilraja A, Krishnakumar B, Subash B, Sobral AJ, Swaminathan M, Shanthi M. Sn loaded Au–ZnO photocatalyst for the degradation of AR 18 dye under UV-A light. J IND ENG CHEM 2016. [DOI: 10.1016/j.jiec.2015.09.010] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
19
|
|
20
|
|
21
|
|
22
|
Senthilraja A, Subash B, Dhatshanamurthi P, Swaminathan M, Shanthi M. Photocatalytic detoxification of Acid Red 18 by modified ZnO catalyst under sunlight irradiation. Spectrochim Acta A Mol Biomol Spectrosc 2015; 138:31-7. [PMID: 25437842 DOI: 10.1016/j.saa.2014.11.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Revised: 10/26/2014] [Accepted: 11/05/2014] [Indexed: 05/25/2023]
Abstract
In this work, hybrid structured Bi-Au-ZnO composite was prepared by precipitation-decomposition method. This method is mild, economical and efficient. Bi-Au-ZnO was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), energy dispersive spectrum (EDS), diffuse reflectance spectra (DRS), photoluminescence spectra (PL) and BET surface area measurements. Photocatalytic activity of Bi-Au-ZnO was evaluated by irradiating the Acid Red 18 (AR 18) dye solution under sun light. Heterostructured Bi-Au-ZnO photocatalyst showed higher photocatalytic activity than those of individual Bi-ZnO, Au-ZnO, bare ZnO, and TiO2-P25 at pH 11. The effects of operational parameters such as the amount of catalyst dosage, dye concentration, initial pH on photo mineralization of AR 18 dye have been analyzed. The mineralization of AR 18 has been confirmed by chemical oxygen demand (COD) measurements. A possible mechanism is proposed for the degradation of AR 18 under sun light. Finally, Bi-Au-ZnO heterojunction photocatalyst was more stable and could be easily recycled several times opening a new avenue for potential industrial applications.
Collapse
Affiliation(s)
- A Senthilraja
- Photocatalysis Laboratory, Department of Chemistry, Annamalai University, Annamalainagar 608 002, Tamil Nadu, India
| | - B Subash
- Photocatalysis Laboratory, Department of Chemistry, Annamalai University, Annamalainagar 608 002, Tamil Nadu, India
| | - P Dhatshanamurthi
- Photocatalysis Laboratory, Department of Chemistry, Annamalai University, Annamalainagar 608 002, Tamil Nadu, India
| | - M Swaminathan
- Photocatalysis Laboratory, Department of Chemistry, Annamalai University, Annamalainagar 608 002, Tamil Nadu, India
| | - M Shanthi
- Photocatalysis Laboratory, Department of Chemistry, Annamalai University, Annamalainagar 608 002, Tamil Nadu, India.
| |
Collapse
|
23
|
Kumar ETD, Thirumalai K, Aravindhan R, Swaminathan M, Rao JR, Nair BU. Visible light photocatalytic degradation of wattle extract: effect of mixing CdWO4 over a semiconductive ZnO photocatalyst. RSC Adv 2015. [DOI: 10.1039/c5ra06926b] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Degradation of wattle (Acacia mearnsii) extract, a leather tanning agent which is mainly composed of polyphenolic compounds was attempted by photocatalytic degradation.
Collapse
Affiliation(s)
- E. T. Deva Kumar
- Chemical Laboratory
- CSIR – Central Leather Research Institute
- Chennai
- India
| | | | - R. Aravindhan
- Leather Processing Division
- CSIR – Central Leather Research Institute
- Chennai
- India
| | | | - J. Raghava Rao
- Chemical Laboratory
- CSIR – Central Leather Research Institute
- Chennai
- India
| | - B. U. Nair
- Chemical Laboratory
- CSIR – Central Leather Research Institute
- Chennai
- India
| |
Collapse
|
24
|
Hauck J, Osho A, Castleberry A, Hartwig M, Reddy L, Phillips-Bute B, Swaminathan M, Mathew J, Stafford-Smith M. Acute kidney injury after ex vivo lung perfusion (EVLP). Transplant Proc 2014; 46:3598-602. [PMID: 25498096 DOI: 10.1016/j.transproceed.2014.06.068] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Accepted: 06/17/2014] [Indexed: 11/24/2022]
Abstract
BACKGROUND Ex vivo lung perfusion (EVLP) identifies viability for marginal organs but complicates and lengthens lung transplantation surgery. Preliminary evidence supports equivalency for EVLP-assisted versus traditional (non-EVLP) procedures regarding graft function, postoperative course, mortality, and survival. However, acute kidney injury (AKI), a common serious complication of lung transplantation, has not been assessed. We tested the hypothesis that EVLP-assisted and non-EVLP lung transplantations are associated with different AKI rates. METHODS Demographic, procedural, and renal data were gathered for 13 EVLP-viable lung transplantations and a non-EVLP group matched 4:1 for single versus double, pulmonary disease, and age. AKI was defined by AKI Network (AKIN) criteria and peak creatinine rise relative to baseline (Δ%Cr) during the 1st 10 postoperative days. Chi-square was performed for AKIN and 2-tailed t test for %ΔCr. RESULTS Patient and procedural characteristics were similar between the groups. One non-EVLP patient required postoperative dialysis. AKI rates were also similar, as assessed by both AKIN (EVLP 7/13 (54%) vs non-EVLP 32/52 (62%); P = .61) and %ΔCr (EVLP 91 ± 81% vs non-EVLP 72 ± 62%; P = .63). CONCLUSIONS We did not observe different AKI rates between EVLP-assisted and traditional lung transplant procedures. Although 1 non-EVLP patient required dialysis, AKI rates were otherwise similar. These findings further support EVLP as a strategy to expand the organ pool and reduce concerns for high-renal risk recipients. The small sample size and retrospective design are limitations. However, our sample size is similar to other reports, and it is the first to analyze AKI after EVLP-assisted lung transplantation. Larger multicenter prospective studies are needed.
Collapse
Affiliation(s)
- J Hauck
- Department of Anesthesiology, Duke University Medical Center, Durham, North Carolina
| | - A Osho
- Department of Surgery, Duke University Medical Center, Durham, North Carolina
| | - A Castleberry
- Department of Surgery, Duke University Medical Center, Durham, North Carolina
| | - M Hartwig
- Department of Surgery, Duke University Medical Center, Durham, North Carolina
| | - L Reddy
- Department of Surgery, Duke University Medical Center, Durham, North Carolina
| | - B Phillips-Bute
- Department of Anesthesiology, Duke University Medical Center, Durham, North Carolina
| | - M Swaminathan
- Department of Anesthesiology, Duke University Medical Center, Durham, North Carolina
| | - J Mathew
- Department of Anesthesiology, Duke University Medical Center, Durham, North Carolina
| | - M Stafford-Smith
- Department of Anesthesiology, Duke University Medical Center, Durham, North Carolina.
| |
Collapse
|
25
|
Subash B, Krishnakumar B, Swaminathan M, Shanthi M. ZnS–Ag–ZnO as an Excellent UV-Light-Active Photocatalyst for the Degradation of AV 7, AB 1, RR 120, and RY 84 Dyes: Synthesis, Characterization, and Catalytic Applications. Ind Eng Chem Res 2014. [DOI: 10.1021/ie5018145] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- B. Subash
- Photocatalysis Laboratory,
Department of Chemistry, Annamalai University, Annamalai Nagar 608 002, Tamil Nadu, India
| | - B. Krishnakumar
- Photocatalysis Laboratory,
Department of Chemistry, Annamalai University, Annamalai Nagar 608 002, Tamil Nadu, India
| | - M. Swaminathan
- Photocatalysis Laboratory,
Department of Chemistry, Annamalai University, Annamalai Nagar 608 002, Tamil Nadu, India
| | - M. Shanthi
- Photocatalysis Laboratory,
Department of Chemistry, Annamalai University, Annamalai Nagar 608 002, Tamil Nadu, India
| |
Collapse
|
26
|
Ravi K, Krishnakumar B, Swaminathan M. BiCl3-loaded montmorillonite K10: a new solid acid catalyst for solvent-free synthesis of bis(indolyl)methanes. Res Chem Intermed 2014. [DOI: 10.1007/s11164-014-1636-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
|
27
|
Muruganandham M, Suri RPS, Sillanpää M, Wu JJ, Ahmmad B, Balachandran S, Swaminathan M. Recent developments in heterogeneous catalyzed environmental remediation processes. J Nanosci Nanotechnol 2014; 14:1898-1910. [PMID: 24749464 DOI: 10.1166/jnn.2014.8718] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
This article reports on recent developments in heterogeneous AOP processes such as photocatalysis, Fenton-like process and catalytic ozonation. The principle, mechanism, and influence of experimental conditions on the degradation of pollutants in heterogeneous catalytic ozonation and the photocatalytic process were discussed. Introducing solid catalysts substantially increased the efficiency of the ozonation process by producing hydroxyl radicals in the degradation process. The different types of catalyst, catalyst dosage, solution pH, ozone flow rate, water matrix and catalytic reusability and stability are reported on here. The list of various semiconductor materials used as photocatalysts, their light absorption properties, various light sources and surface properties such as surface area, pore size and pore volume as a factor in the photocatalytic degradation of various pollutants are discussed. The review article also discussed the pollutants degraded using these three processes.
Collapse
|
28
|
Subash B, Senthilraja A, Dhatshanamurthi P, Swaminathan M, Shanthi M. Solar active photocatalyst for effective degradation of RR 120 with dye sensitized mechanism. Spectrochim Acta A Mol Biomol Spectrosc 2013; 115:175-82. [PMID: 23832224 DOI: 10.1016/j.saa.2013.06.027] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2013] [Revised: 06/03/2013] [Accepted: 06/05/2013] [Indexed: 05/21/2023]
Abstract
Solar active WO3 loaded Ag-ZnO (WO3-Ag-ZnO) was successfully synthesized by precipitation-decomposition method. XPS reveals that the presence of metallic silver in the catalyst. The photocatalytic activity of WO3-Ag-ZnO was investigated for the degradation of Reactive Red 120 (RR 120) in aqueous solution using solar light. WO3-Ag-ZnO is found to be more efficient than Ag-ZnO, WO3-ZnO, Ag-WO3, commercial ZnO, prepared ZnO, Degussa TiO2-P25, pure WO3 and TiO2 (Merck) at pH 7 for the mineralization of RR 120. The effects of operational parameters such as the amount of photocatalyst, dye concentration, initial pH on photo mineralization of RR 120 have been analyzed. The mineralization of RR 120 has been confirmed by COD measurements. A dual mechanism has been proposed for efficient degradation of RR 120 dye with WO3-Ag-ZnO under solar light at neutral pH. This catalyst is found to be reusable.
Collapse
Affiliation(s)
- B Subash
- Photocatalysis Laboratory, Department of Chemistry, Annamalai University, Annamalainagar, 608 002 Tamil Nadu, India
| | | | | | | | | |
Collapse
|
29
|
Krishnakumar B, Swaminathan M. Product Selectivity in Solar Photocatalytic Dehydrazonation of Aromatic Hydrazones by TiO2-Based Catalysts. ACTA ACUST UNITED AC 2013. [DOI: 10.1080/15533174.2013.768650] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- B. Krishnakumar
- a Photocatalysis Laboratory, Department of Chemistry , Annamalai University , Annamalainagar , Tamil Nadu , India
| | - M. Swaminathan
- a Photocatalysis Laboratory, Department of Chemistry , Annamalai University , Annamalainagar , Tamil Nadu , India
| |
Collapse
|
30
|
Subash B, Krishnakumar B, Swaminathan M, Shanthi M. β-Ag2S–ZnO as a novel sunshine photocatalyst for the effective degradation of RR 120 dye. POWDER TECHNOL 2013. [DOI: 10.1016/j.powtec.2013.03.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
31
|
Zanotti G, Shaw L, Castleberry A, Schroder J, Velazquez E, Swaminathan M, Rogers J, Milano C. Natural History of Tricuspid Valve Regurgitation (TR) Diagnosed Immediately after Heart Transplant. J Heart Lung Transplant 2013. [DOI: 10.1016/j.healun.2013.01.663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
|
32
|
Vijayabalan A, Selvam K, Krishnakumar B, Swaminathan M. Photocatalytic degradation of Reactive Orange 4 by surface fluorinated TiO2 Wackherr under UV-A light. Sep Purif Technol 2013. [DOI: 10.1016/j.seppur.2013.01.025] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
33
|
Subash B, Krishnakumar B, Swaminathan M, Shanthi M. Ag2S-ZnO--an efficient photocatalyst for the mineralization of Acid Black 1 with UV light. Spectrochim Acta A Mol Biomol Spectrosc 2013; 105:314-319. [PMID: 23318775 DOI: 10.1016/j.saa.2012.12.035] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2012] [Revised: 12/02/2012] [Accepted: 12/06/2012] [Indexed: 06/01/2023]
Abstract
The Ag(2)S loaded ZnO (Ag(2)S-ZnO) was successfully synthesized by precipitation of zinc oxalate and Ag(2)S and calcination of the mixed precipitate at 400 °C for 12 h. The catalyst was characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) images, energy dispersive spectra (EDS), diffuse reflectance spectra (DRS) photoluminescence spectra (PL) and BET surface area measurements. The photocatalytic activity of Ag(2)S-ZnO was investigated for the degradation of Acid Black (AB 1) in aqueous solution using UV light. Ag(2)S-ZnO is found to be more efficient than commercial ZnO, prepared ZnO and TiO(2)-P25 at pH 9 for the mineralization of Acid Black 1. The effects of operational parameters such as the amount of photocatalyst, dye concentration, initial pH on photo mineralization have been analyzed. Mechanism of degradation by Ag(2)S-ZnO is proposed. The mineralization of Acid Black 1 has also been confirmed by COD measurements. The catalyst is found to be reusable.
Collapse
Affiliation(s)
- B Subash
- Photocatalysis Laboratory, Department of Chemistry, Annamalai University, Annamalainagar 608 002, Tamil Nadu, India
| | | | | | | |
Collapse
|
34
|
Subash B, Krishnakumar B, Swaminathan M, Shanthi M. Highly efficient, solar active, and reusable photocatalyst: Zr-loaded Ag-ZnO for Reactive Red 120 dye degradation with synergistic effect and dye-sensitized mechanism. Langmuir 2013; 29:939-49. [PMID: 23234536 DOI: 10.1021/la303842c] [Citation(s) in RCA: 104] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The different wt % of Zr-codoped Ag-ZnO catalysts were prepared by the simple precipitation-thermal decomposition method and used for degradation of anionic azo dye Reactive Red 120 (RR 120) under natural sunlight. Highly efficient 4 wt % of Zr-codoped Ag-ZnO was characterized by X-ray diffraction (XRD), high-resolution transmission electron microscope (HR-TEM) images, field emission scanning electron microscope (FE-SEM) images, energy-dispersive spectra (EDS), diffuse reflectance spectra (DRS), photoluminescence spectra (PL), cyclic voltammetry (CV), X-ray photoelectron spectroscopy (XPS), and BET surface area measurements. Metal codopants increase the absorbance of ZnO to the entire visible region. XRD and XPS reveal that Ag is in the form of Ag(0) and Zr in the form of Zr(4+). The photocatalytic activity of 4 wt % Zr-codoped Ag-ZnO was compared with other single-metal-doped, undoped, and commercial catalysts. The quantum yields of all processes were determined and analyzed. Zr-Ag-ZnO was found to be more efficient than Ag-ZnO, Zr-ZnO, commercial ZnO, prepared ZnO, TiO(2)-P25, and TiO(2) at neutral pH for mineralization of RR 120 under solar light. To the best of our knowledge, this is the first report on the synthesis of Zr-codoped Ag-ZnO and its use in the degradation of RR 120 dye under natural sunlight illuminatioin. The influences of operational parameters such as the amount of photocatalyst, dye concentration, and initial pH on photomineralization of RR 120 have been analyzed. Mineralization of RR 120 has been confirmed by chemical oxygen demand (COD) measurements. A dual mechanism has been proposed for the higher efficiency of Zr-Ag-ZnO at neutral pH under solar light. This catalyst is found to be reusable.
Collapse
Affiliation(s)
- B Subash
- Photocatalysis Laboratory, Department of Chemistry, Annamalai University, Annamalainagar, Tamil Nadu, India
| | | | | | | |
Collapse
|
35
|
Subash B, Krishnakumar B, Swaminathan M, Shanthi M. Enhanced photocatalytic performance of WO3 loaded Ag–ZnO for Acid Black 1 degradation by UV-A light. ACTA ACUST UNITED AC 2013. [DOI: 10.1016/j.molcata.2012.09.008] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
|
36
|
Krishnakumar B, Swaminathan M. Photodegradation of Acid Violet 7 with AgBr-ZnO under highly alkaline conditions. Spectrochim Acta A Mol Biomol Spectrosc 2012; 99:160-165. [PMID: 23063859 DOI: 10.1016/j.saa.2012.08.077] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/21/2012] [Revised: 08/20/2012] [Accepted: 08/24/2012] [Indexed: 06/01/2023]
Abstract
The photocatalytic activity of AgBr-ZnO was investigated for the degradation of Acid Violet 7 (AV 7) in aqueous solution using UV-A light. AgBr-ZnO is found to be more efficient than commercial ZnO and prepared ZnO at pH 12 for the mineralization of AV 7. The effects of operational parameters such as the amount of photocatalyst, dye concentration, initial pH on photo mineralization have been analyzed. Expect oxone, other oxidants decrease the degradation efficiency. Addition of metal ions and anions decrease the degradation efficiency of AgBr-ZnO significantly. The mineralization of AV 7 has also been confirmed by COD measurements. The mechanism of degradation by AgBr-ZnO is proposed to explain its higher activity under UV light. The catalyst is found to be reusable.
Collapse
Affiliation(s)
- B Krishnakumar
- Photocatalysis Laboratory, Department of Chemistry, Annamalai University, Annamalainagar 608 002, Tamil Nadu, India
| | | |
Collapse
|
37
|
Subash B, Krishnakumar B, Swaminathan M, Shanthi M. Solar-light-assisted photocatalytic degradation of NBB dye on Zr-codoped Ag–ZnO catalyst. Res Chem Intermed 2012. [DOI: 10.1007/s11164-012-0831-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
38
|
Velmurugan R, Krishnakumar B, Kumar R, Swaminathan M. Solar active nano-TiO2 for mineralization of Reactive Red 120 and Trypan Blue. ARAB J CHEM 2012. [DOI: 10.1016/j.arabjc.2010.12.023] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
|
39
|
Subash B, Krishnakumar B, Pandiyan V, Swaminathan M, Shanthi M. An efficient nanostructured Ag2S–ZnO for degradation of Acid Black 1 dye under day light illumination. Sep Purif Technol 2012. [DOI: 10.1016/j.seppur.2012.06.002] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
|
40
|
Ravi K, Selvam K, Swaminathan M. Photochemical synthesis and antimicrobial screening of some substituted dihydrobenzofurans. Res Chem Intermed 2012. [DOI: 10.1007/s11164-012-0555-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
41
|
Rajagopal K, Daneshmand M, Schechter M, Ganapathi A, Patel C, Rogers J, Bottiger B, Swaminathan M, Milano C. 767 Impact of Left Ventricular Assist Device Implantation upon Native Aortic Valve Regurgitation. J Heart Lung Transplant 2012. [DOI: 10.1016/j.healun.2012.01.783] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
|
42
|
Krishnakumar B, Subash B, Swaminathan M. AgBr–ZnO – An efficient nano-photocatalyst for the mineralization of Acid Black 1 with UV light. Sep Purif Technol 2012. [DOI: 10.1016/j.seppur.2011.09.037] [Citation(s) in RCA: 147] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
|
43
|
Annadhasan M, Selvam K, Swaminathan M. A Combined-Redox Synthesis of 2-Alkylbenzimidazoles from 2-Nitroanilines by Semiconductor Photocatalysis. SYNTHETIC COMMUN 2012. [DOI: 10.1080/00397911.2010.541587] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Affiliation(s)
- M. Annadhasan
- a Department of Chemistry , Annamalai University , Annamalainagar , India
| | - K. Selvam
- a Department of Chemistry , Annamalai University , Annamalainagar , India
| | - M. Swaminathan
- a Department of Chemistry , Annamalai University , Annamalainagar , India
| |
Collapse
|
44
|
Subash B, Krishnakumar B, Velmurugan R, Swaminathan M, Shanthi M. Synthesis of Ce co-doped Ag–ZnO photocatalyst with excellent performance for NBB dye degradation under natural sunlight illumination. Catal Sci Technol 2012. [DOI: 10.1039/c2cy20254a] [Citation(s) in RCA: 162] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
45
|
Ravi K, Krishnakumar B, Swaminathan M. An Efficient Protocol for the Green and Solvent-Free Synthesis of Azine Derivatives at Room Temperature Using BiCl3-Loaded Montmorillonite K10 as a New Recyclable Heterogeneous Catalyst. ISRN Org Chem 2012; 2012:595868. [PMID: 24052847 PMCID: PMC3767373 DOI: 10.5402/2012/595868] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/28/2012] [Accepted: 10/02/2012] [Indexed: 11/26/2022]
Abstract
A new BiCl3-loaded montmorillonite K10 catalyst has been prepared by solid dispersion method and was characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and cyclic voltammetry (CV) measurements. BiCl3 loaded K10 (BiCl3-K10) has been used as solid acid catalyst for the synthesis of azine derivatives from benzophenone hydrazone and ketones/aldehydes by simple physical grinding. This BiCl3-K10 gives an excellent yield with short reaction time and is an inexpensive, easily recyclable catalyst for this reaction.
Collapse
Affiliation(s)
- K Ravi
- Photocatalysis Laboratory, Department of Chemistry, Annamalai University, Annamalainagar 608 002, Tamil Nadu, India
| | | | | |
Collapse
|
46
|
Krishnakumar B, Swaminathan M. An expeditious and solvent free synthesis of azine derivatives using sulfated anatase–titania as a novel solid acid catalyst. CATAL COMMUN 2011. [DOI: 10.1016/j.catcom.2011.08.029] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022] Open
|
47
|
Krishnakumar B, Swaminathan M. Influence of operational parameters on photocatalytic degradation of a genotoxic azo dye Acid Violet 7 in aqueous ZnO suspensions. Spectrochim Acta A Mol Biomol Spectrosc 2011; 81:739-44. [PMID: 21788154 DOI: 10.1016/j.saa.2011.07.019] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2011] [Revised: 06/28/2011] [Accepted: 07/03/2011] [Indexed: 05/13/2023]
Abstract
The photocatalytic degradation of a genotoxic azo dye Acid Violet 7 (AV 7) using ZnO as a photocatalyst in aqueous solution has been investigated under UV irradiation. The degradation is higher with UV/ZnO process than with UV/TiO(2)-P25 process at pH 9. The effects of different parameters such as pH of the solution, amount of catalyst, initial dye concentration and the influence of cations, anions and oxidants on photodegradation of AV 7 were analyzed. Addition of oxidants except H(2)O(2) has no significant effect on degradation. The degradation of AV 7 follows pseudo-first order kinetics according to the Langmuir-Hinshelwood model. The degradation of AV 7 has also been confirmed by COD and CV measurements.
Collapse
Affiliation(s)
- B Krishnakumar
- Department of Chemistry, Annamalai University, Annamalainagar 608 002, Tamilnadu, India
| | | |
Collapse
|
48
|
Velmurugan R, Selvam K, Krishnakumar B, Swaminathan M. An efficient reusable and antiphotocorrosive nano ZnO for the mineralization of Reactive Orange 4 under UV-A light. Sep Purif Technol 2011. [DOI: 10.1016/j.seppur.2011.04.018] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
49
|
Affiliation(s)
- B. Krishnakumar
- a Department of Chemistry , Annamalai University , Annamalainagar, India
| | - K. Selvam
- a Department of Chemistry , Annamalai University , Annamalainagar, India
| | - M. Swaminathan
- a Department of Chemistry , Annamalai University , Annamalainagar, India
| |
Collapse
|
50
|
Rajamohan R, Kothai Nayaki S, Swaminathan M. A Study on Host–Guest Complexation of 5-Amino-2-Mercaptobenzimidazole with β-Cyclodextrin. J SOLUTION CHEM 2011. [DOI: 10.1007/s10953-011-9691-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|