ZnO nanoparticles as efficient sunlight driven photocatalyst prepared by solution combustion method involved lime juice as biofuel

Starch-Assisted Eco-Friendly Synthesis of ZnO Nanoparticles: Enhanced Photocatalytic, Supercapacitive, and UV-Driven Antioxidant Properties with Low Cytotoxic Effects

This study presents an efficient and environmentally sustainable synthesis of ZnO nanoparticles using a starch-mediated sol-gel approach. This method yields crystalline mesoporous ZnO NPs with a hexagonal wurtzite structure. The synthesized nanoparticles demonstrated remarkable multifunctionality across three critical applications. In photocatalysis, the ZnO NPs exhibited exceptional efficiency, achieving complete degradation of methylene blue within 15 min at pH 11, significantly surpassing the performance of commercial ZnO. Under neutral pH conditions, the nanoparticles effectively degraded various organic dyes, including methylene blue, rhodamine B, and methyl orange, following pseudo-first-order kinetics. The methylene blue degradation process was aligned with the Langmuir-Hinshelwood model, emphasizing their advanced catalytic properties. For supercapacitor applications, the ZnO NPs attained a high specific capacitance of 550 F/g at 1 A/g, underscoring their potential as energy storage solutions. Additionally, the nanoparticles demonstrated strong UV-induced antiradical activity, with an EC50 of 32.2 μg/mL in DPPH assays. Notably, the cytotoxicity evaluation revealed an LC50 of 1648 μg/mL, indicating excellent biocompatibility. This study highlights a sustainable approach for the synthesis of multifunctional ZnO NPs that offers effective solutions for environmental remediation, energy storage, and biomedical applications.

Photocatalytic activity and anticancer properties of green synthesized ZnO-MgO-Mn2O3 nanocomposite via Ocimum basilicum L. seed extract

Green synthesis using plant extracts such as Ocimum basilicum L. (OBL) seed has attracted attention due to its sustainable and environmentally friendly nature. In this study, ZnO-MgO-Mn2O3 nanocomposites were synthesized using OBL seed extract at two different calcination temperatures of 500 °C and 600 °C, and evaluated in terms of photocatalytic application and cytotoxicity. Phytochemicals in OBL seeds act as reducing and masking agents in the production route, which leads to the formation of nanomaterials with unique properties. Characterization techniques, including XRD, FE-SEM, and DRS were used to analyze the structural, morphological, and optical features of the nanocomposite. XRD results confirmed increasing crystal size from ~ 32 nm (500 °C) to ~ 84 nm (600 °C). Also, FE-SEM images showed formation of irregularly shaped nanocomposites and the EDX spectra of the samples confirmed the presence of zinc, magnesium, manganese, and oxygen elements. The photocatalytic behavior of the nanocomposite cacined at 500 °C was investigated for different organic pollutants. Removal percentages of 97% for Eriochrome Black T dye (pH = 10 for 90 min), 99% for methylene blue dye (pH = 10 for 60 min), 89% for methyl orange dye (pH = 10 for 105 min), and 86.9% for Rhodamine B dye (pH = 3 for 90 min) were obtained. Moreover, the cytotoxicity of the synthesized nanocomposite at 500 °C was evaluated on the 4T1 cell line to investgate its effect on biological systems, and the IC50 value was obtained around 323 µg/mL.

Enhanced photocatalytic activity of green synthesized zinc oxide nanoparticles using low-cost plant extracts

Developing stable and highly efficient metal oxide photocatalysts remains a significant challenge in managing organic pollutants. In this study, zinc oxide nanoparticles (ZnO NPs) were successfully synthesized using various plant extracts, pomegranate (P.M), beetroot roots (B.S), and seder, along with a chemical process. The produced ZnO NPs were characterized using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), ultraviolet-visible spectroscopy (UV-Vis), Field Emission Scanning Electron Microscope (FESEM), High-Resolution Transmission Electron Microscopy (HRTEM), and Surface Area. For all prepared samples, the results indicated that the composition of the plant extract affects several characteristics of the produced particles, such as their photocatalytic properties, energy bandgap (Eg), particle size, and the ratio of the two intensity (0 0 2) and (1 0 0) crystalline planes. The particle size of the produced NPs varies between 20 and 30 nm. To examine NPs' photocatalytic activity in the presence of UV light, Methyl Orange (MO) was utilized. The Eg of  ZnO synthesized by the chemical method was 3.16 e. V, whereas it was 2.84, 2.63, and 2.59 for P.M, Seder, and B.S extracts, respectively. The most effective ZnO NPs, synthesized using Beetroots, exhibited a degradation efficiency of 87 ± 0.5% with a kinetic rate constant of 0.007 min-1. The ratio of the two intensity (0 0 2) and (1 0 0) crystalline planes was also examined to determine a specific orientation in (0 0 2) that is linked to the production of oxygen vacancies in ZnO, which enhances their photocatalytic efficiency. Furthermore, the increase in photocatalytic effectiveness can be attributed to the improved light absorption by the inter-band gap states and effective charge transfer.

Green synthesis of zinc oxide nanoparticles using Rhus coriaria extract and their anticancer activity against triple-negative breast cancer cells

The growing interest in using plant extracts for the biogenic synthesis of zinc oxide nanoparticles (ZnO NPs) stems from their facile, eco-friendly, and biologically safe approach instead of chemical routes. For the first time, ZnO NPs were successfully biosynthesized using Rhus coriaria fruit aqueous extract as a reducing and capping agent. Characterization revealed that the biosynthesized ZnO NPs possessed a maximum absorbance of approximately 359 nm and closely resembled the hexagonal ZnO wurtzite crystalline structure, with an average crystalline size of 16.69 nm. The transmission electron microscope (TEM) showed the presence of spherical and hexagonal morphologies, with an average grain size of 20.51 ± 3.90 nm. Moreover, the elemental composition of the synthesized ZnO NPs was assessed via energy-dispersive X-ray spectrometry (EDX), and the presence of phytocompounds on their surface was subsequently verified through FT-IR analysis. The ζ-potential of ZnO NPs was recorded at - 19.9 ± 0.1663 mV. Regarding anti-cancer properties, ZnO NPs were found to possess potent anti-tumor effects on MCF-7 and MDA-MB-231 breast cancer cells. Their efficacy was dose-dependent, with IC50 values ranging from 35.04-44.86 μg/mL for MCF-7 and 55.54-63.71 µg/mL for MDA-MB-231 cells. Mechanistic studies in MDA-MB-231 cells revealed apoptosis induction, validated by DAPI staining, confocal microscopy, and Annexin V/PI staining, showing apoptosis by 12.59% and 81.57% at ½ IC50 and IC50 values, respectively. Additionally, ZnO NPs were observed to provoke S-phase arrest and inhibit colony-forming and metastatic potential by modulating apoptosis and metastasis-related genes. This study unravels new insights into how ZnO NPs provoke cancer cell death and inhibit metastasis, revealing new prospects in cancer nanotechnology.

Enhanced photocatalytic degradation of crystal violet dye and high-performance electrochemical supercapacitor applications of hydrothermally synthesised magnetic bifunctional nanocomposite (Fe3O4/ZnO)

The present investigation employed a facile hydrothermal approach for the fabrication of Fe3O4/ZnO dual-functional magnetic nanocomposite. Supercapacitor and visible-light-driven photocatalytic applications of the material were explored. X-ray diffraction, Fourier transform infrared spectra, ultraviolet-visible diffuse reflectance spectra (UV-vis/DRS), field emission scanning electron microscopy (FE-SEM), energy dispersive x-ray spectroscopy, and vibrating sample magnetometer were used to analyse the nanocomposite's structural, morphological, optical, and magnetic properties. The FE-SEM analysis demonstrated that the surface morphology of Fe3O4, ZnO, and the Fe3O4/ZnO nanocomposite consisted of nanoparticles, nanoflakes, and nanoparticles adhered to the nanoflakes, respectively. The maximum specific capacitance of the electrode based on the Fe3O4/ZnO nanocomposite was measured to be 736.36 Fg-1at a scan rate of 5 mVs-1. The electrode also demonstrated remarkable cycling stability, retaining 86.5% of its capacitance even after 3000 cycles. The Fe3O4/ZnO nanocomposite was found to have an optical bandgap of 2.7 eV, an average particle size of 22.5 nm, and a saturation magnetization of 68.7 emu g-1. The photocatalysis experiment was conducted using the optimised settings, which included a pH of 7.0, a dye concentration of 30 mg l-1, a catalyst dose of 1 g l-1, and a contact time of 120 min. The Fe3O4/ZnO nanocomposite exhibited a notable degradation efficiency towards crystal violet dye upon exposure to visible light, achieving a degradation efficiency of 96.9%. This performance surpassed that of pure ZnO, which attained a degradation efficiency of 70.2%. The nanocomposite exhibited a rate constant of 2.80 × 10-2min-1, which was found to be notably higher than that of pure ZnO (0.8 × 10-2min-1), as determined through modelling (pseudo-first order linear fit). The radical scavenger experiments indicated that the superoxide radicals and hydroxyl radicals are the primary reactive species. The Fe3O4/ZnO photocatalyst can be effectively isolated using a bar magnet. Remarkably, the photocatalytic efficiency of the material remained almost entirely intact even after undergoing four cycles of recycling. In addition, this research opens up exciting new possibilities for use in fields like energy storage and pollution control.

Preparation and characterization analysis of biofuel derived through seed extracts of Ricinus communis (castor oil plant)

The current study assesses the prospect of using R. Communis seed oil as a substitute fuel for diesel engines. Biodiesel is prepared from the R. Communis plant seed oil by a single-step base catalytic transesterification procedure. The investigation deals with the Physico-chemical characteristics of R. Communis biodiesel and has been associated with the base diesel. It has been perceived that the characteristics of biodiesel are well-matched with the base diesel under the ASTM D6751 limits correspondingly. R. Communis biodiesel is blended in different proportions with base diesel such as D10, D20, D30, D40, D50 and D100 and is tested in a Kirloskar TV1 single-cylinder, 4 blows DI engine under altered loading conditions. Outcomes demonstrate that BTE and BSFC for D10 as well as D20 are similar to base diesel. BSFC indicates that the precise BSFC of base diesel, D10, D20, D30, D40 and D50 was 0.87, 1.70, 2.60, 3.0, 3.4, and 3.5 kg/kW-hr, respectively. The extreme BTE at full load condition for base diesel, D10, D20, D30, D40, D50 and D100 are 28.2%, 28.1%, 27.9%, 25.5%, 24.1%, and 23.6% , respectively. In the case of engine emissions, R. Communis biodiesel blends provided an average decrease in hydrocarbon (HC), Carbon-monoxide (CO) and carbon dioxide (CO2) associated with base diesel. Nevertheless, R. Communis biodiesel blends discharged high stages of nitrogen oxide (NOx) compares to base diesel. Base diesel, D10, D20, D30, D40, D50, and D100 had UBHC emissions of 45 ppm, 40 ppm, 44 ppm, 46 ppm, 41 ppm, and 43 ppm, respectively. The reduction in CO emissions for D10, D20, D30, D40, D50 and D100 are 0.13%, 0.14%, 0.17%, 0.18% and 0.21% respectively. The dissimilarity in NOx attentiveness within brake powers for D10, D20, D30, D40, and D50 and base diesel are 50-ppm, 100 ppm, 150 ppm, 250 ppm, 350 ppm, and 500 ppm, respectively. The dissimilarity of CO₂ emanation with reverence to break powers for the base-diesel, D10, D20, D30, D40, D50, and D100 are 4.8%, 4.9%, 4.8%, 4.56%, 4.9% and 5.1%, respectively. The present research provides a way for renewable petrol blends to substitute diesel for powering diesel engines in that way dropping the reliance on fossil fuels.

Patent Blue V Dye Adsorption by Fresh and Calcined Zn/Al LDH: Effect of Process Parameters and Experimental Design Optimization

This work focuses on the adsorptive removal of patent blue V (PBV) dye from aqueous solution by Zn/Al layered double hydroxide in fresh (LDH) and calcined (CLDH) forms. The material was synthesized via coprecipitation and samples were characterized by XRD, FTIR and TGA-DTA. Dye retention was evaluated under different experimental conditions of contact time, pH, adsorbent dosage, temperature and initial dye concentration. Experimental results show that highest adsorption capacity occurred at acidic medium. Kinetics data were properly fitted with the pseudo-second-order model. Equilibrium data were best correlated to Langmuir model with maximum monolayer adsorption capacities of 185.40 and 344.37 mg/g, respectively, for LDH and CLDH. The process was endothermic and spontaneous in nature. Based on the preliminary study, full factorial experimental design (24) was used for the optimization of the effect of solution pH, adsorbent dose, initial dye concentration and the calcination. Thus, the optimal conditions to reach high equilibrium adsorption capacity were achieved at pH of 5, adsorbent dosage of 0.1 g/L, and initial dye concentration of 15 mg/L by CLDH.