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Bharagav U, Ramesh Reddy N, Nava Koteswara Rao V, Ravi P, Sathish M, Rangappa D, Prathap K, Shilpa Chakra C, Shankar MV, Appels L, Aminabhavi TM, Kakarla RR, Mamatha Kumari M. Bifunctional g-C 3N 4/carbon nanotubes/WO 3 ternary nanohybrids for photocatalytic energy and environmental applications. Chemosphere 2023; 311:137030. [PMID: 36334741 DOI: 10.1016/j.chemosphere.2022.137030] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2022] [Revised: 09/08/2022] [Accepted: 10/24/2022] [Indexed: 06/16/2023]
Abstract
Ternary nanohybrids based on mesoporous graphitic carbon nitride (g-C3N4) were synthesized and presented for developing stable and efficient Hydrogen (H2) production system. Based on photocatalytic activity, optimization was performed in three different stages to develop carbon nanotubes (CNTs) and WO3 loaded g-C3N4 (CWG-3). Initially, the effect of exfoliation was investigated, and a maximum specific surface area of 100.77 m2/g was achieved. 2D-2D interface between WO3 and g-C3N4 was targeted and achieved, to construct a highly efficient direct Z-scheme heterojunction. Optimized binary composite holds the enhanced activity of about 2.6 folds of H2 generation rates than the thermally exfoliated g-C3N4. Further, CNT loading towards binary composite in an optimized weight ratio enhances the activity by 6.86 folds than the pristine g-C3N4. Notably, optimized ternary nanohybrid generates 15,918 μmol h-1. g-1cat of molecular H2, under natural solar light irradiation with 5 vol% TEOA as a sacrificial agent. Constructive enhancements deliver remarkable H2 production and dye degradation activities. Results evident that, the same system can be useful for pilot-scale energy generation and other photocatalytic applications as well.
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Affiliation(s)
- U Bharagav
- Nanocatalysis and Solar Fuels Research Laboratory, Department of Materials Science & Nanotechnology, Yogi Vemana University, Kadapa, 516 005, Andhra Pradesh, India
| | - N Ramesh Reddy
- Nanocatalysis and Solar Fuels Research Laboratory, Department of Materials Science & Nanotechnology, Yogi Vemana University, Kadapa, 516 005, Andhra Pradesh, India
| | - V Nava Koteswara Rao
- Nanocatalysis and Solar Fuels Research Laboratory, Department of Materials Science & Nanotechnology, Yogi Vemana University, Kadapa, 516 005, Andhra Pradesh, India
| | - P Ravi
- Electrochemical Power Sources Division, CSIR-Central Electrochemical Research Institute- Karaikudi, Tamil Nadu, India
| | - M Sathish
- Electrochemical Power Sources Division, CSIR-Central Electrochemical Research Institute- Karaikudi, Tamil Nadu, India
| | - Dinesh Rangappa
- Visvesvaraya Center for Nano Science and Technology, Visvesvaraya Technological University, Muddenahalli, Chikkaballapura, Karnataka, India
| | - K Prathap
- Centre for Advanced Studies in Electronics Science and Technology (CASEST), School of Physics, University of Hyderabad, Gachibowli, Hyderabad, India
| | - Ch Shilpa Chakra
- Jawaharlal Nehru Technological University Hyderabad (JNTUH), Kukatpally, Hyderabad, Telangana, India
| | - M V Shankar
- Nanocatalysis and Solar Fuels Research Laboratory, Department of Materials Science & Nanotechnology, Yogi Vemana University, Kadapa, 516 005, Andhra Pradesh, India
| | - Lise Appels
- KU Leuven, Department of Chemical Engineering, Process and Environmental Technology Lab, Jan Pieter De Nayerlaan 5, B-2860, Sint-Katelijne-Waver, Belgium
| | - Tejraj M Aminabhavi
- School of Advanced Sciences, KLE Technological University, Hubballi, 580031, Karnataka, India; School of Engineering, University of Petroleum and Energy Studies, Dehradun, India.
| | - Raghava Reddy Kakarla
- School of Chemical and Biomolecular Engineering, The University of Sydney, Sydney, NSW 2006, Australia.
| | - M Mamatha Kumari
- Nanocatalysis and Solar Fuels Research Laboratory, Department of Materials Science & Nanotechnology, Yogi Vemana University, Kadapa, 516 005, Andhra Pradesh, India.
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Manyangadze M, Chikuruwo NMH, Narsaiah TB, Chakra CS, Charis G, Danha G, Mamvura TA. Adsorption of lead ions from wastewater using nano silica spheres synthesized on calcium carbonate templates. Heliyon 2020; 6:e05309. [PMID: 33204869 PMCID: PMC7649267 DOI: 10.1016/j.heliyon.2020.e05309] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Revised: 08/07/2020] [Accepted: 10/15/2020] [Indexed: 12/03/2022] Open
Abstract
Lead is a heavy metal that is bio accumulative and non-biodegradable that poses a threat to our health when it exists in excess in our bloodstream. It has found its way into wastewater from mostly chemical industrial processes. In this article, we investigated the adsorption and hence removal of lead (II) ions from wastewater in order to purify it for re-use in industrial processes or for plant and animal use. We synthesized nano silica hollow spheres (NSHS) and used them as adsorbents to remove lead ions from wastewater. When we characterized the NSHS using X-Ray diffraction, the amorphous nature of silica was evident with average crystal size of 39.5 nm. Scanning electron microscopy was used to determine the morphology of the adsorbent and the particles were found to be spherical in shape within a size range of 100–200 nm. Thermogravimetric analysis was used to determine the mass loss of NSHS which was ~2% at 800 °C. Our experimental results from adsorption studies showed that there was a linear relationship between temperature (27–60 °C) and adsorption efficiency and an inverse relationship between initial metal concentration (50–300 mg/L) and adsorption efficiency. At a maximum temperature of 60 °C and maximum initial metal concentration of 300 mg/L, the adsorption capacity was 200 mg/g and 262 mg/g, respectively while the adsorption efficiency was 99.6% and 87.4%, respectively. Our equilibrium and thermodynamic results revealed that the process was better modelled by the Langmuir adsorption isotherm (qmax = 266.89 mg/g and b = 0.89 L/mg). The adsorption process was both endothermic (ΔH = 97 kJ/mol) and spontaneous (ΔG = -22 kJ/mol). We can conclude that we were able to successfully synthesize NSHS, use them to remove lead (II) ions and the produced NSHS have a capacity that is higher than most other adsorbents investigated by other researchers.
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Affiliation(s)
- Milton Manyangadze
- Chemical and Process Systems Engineering Department, Harare Institute of Technology, Harare, Zimbabwe
| | - Nyaradzai M H Chikuruwo
- Industial and Manufacturing Engineering Department, Harare Institute of Technology, Harare, Zimbabwe
| | - T Bala Narsaiah
- Institute of Chemical Sciences and Technology, Jawaharlal Nehru Technological University, Hyderabad, India
| | - Ch Shilpa Chakra
- Institute of Chemical Sciences and Technology, Jawaharlal Nehru Technological University, Hyderabad, India
| | - Gratitude Charis
- Department of Chemical, Materials and Metallurgical Engineering, College of Engineering and Technology, Botswana International University of Science and Technology, Plot 10071, Boseja Ward, Private Bag 16 Palapye, Botswana
| | - Gwiranai Danha
- Department of Chemical, Materials and Metallurgical Engineering, College of Engineering and Technology, Botswana International University of Science and Technology, Plot 10071, Boseja Ward, Private Bag 16 Palapye, Botswana
| | - Tirivaviri A Mamvura
- Department of Chemical, Materials and Metallurgical Engineering, College of Engineering and Technology, Botswana International University of Science and Technology, Plot 10071, Boseja Ward, Private Bag 16 Palapye, Botswana
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Pavani T, Rao KV, Chakra CS, Prabhu YT. Synthesis and characterization of γ-ferric oxide nanoparticles and their effect on Solanum lycopersicum. Environ Sci Pollut Res Int 2016; 23:9373-9380. [PMID: 26296507 DOI: 10.1007/s11356-015-5215-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [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: 03/10/2015] [Accepted: 08/10/2015] [Indexed: 06/04/2023]
Abstract
γ-Ferric oxide nanoparticles are synthesized through modern and facile ayurvedic route followed by normal and special purification steps, which are both cost-effective and eco-friendly. These synthesized γ-ferric oxide nanoparticles were applied on Solanum lycopersicum to search the effect on chlorophyll content. This process involves multiple filtration and calcination steps. The synthesized samples were analyzed by X-ray diffraction (XRD), UV-visible (UV-vis) spectroscopy, transmission electron microscopy (TEM), vibrating sample magnetometry (VSM), and particle size analysis (PSA) to identify the purification step's influence on the structural, optical, morphological, magnetic, and particle size properties of ferric oxide nanoparticles (γ-phase). X-ray diffraction has revealed that ferric oxide nanoparticles have rhombohedral structure of α-phase (hematite) in initial purification process later transformed into cubic structure γ-phase (maghemite). UV-vis spectroscopy analysis has clearly shown that by repetitive purification steps, λmax has increased from 230 to 340 nm. TEM result has an intercorrelation with XRD results. γ-Ferric oxide nanoparticles were tested on Solanum lycopersicum (tomato seeds). The changes in the contents of chlorophyll a, chlorophyll b, and total carotene were studied using spectral measurements at two different dosages-0.5 and 2 M. As a result, at 0.5-M concentration, magnetic nanoparticles exhibit fruitful results by increasing the crop yield and being more resistant to chlorosis.
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Affiliation(s)
- Tambur Pavani
- Center for Nano Science and Technology, Institute of Science and Technology, Jawaharlal Nehru Technological University Hyderabad, Kukatpally, Hyderabad, 500085, India
| | - K Venkateswara Rao
- Center for Nano Science and Technology, Institute of Science and Technology, Jawaharlal Nehru Technological University Hyderabad, Kukatpally, Hyderabad, 500085, India.
| | - Ch Shilpa Chakra
- Center for Nano Science and Technology, Institute of Science and Technology, Jawaharlal Nehru Technological University Hyderabad, Kukatpally, Hyderabad, 500085, India
| | - Y T Prabhu
- Center for Nano Science and Technology, Institute of Science and Technology, Jawaharlal Nehru Technological University Hyderabad, Kukatpally, Hyderabad, 500085, India
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