Hydrothermal Synthesis and Photocatalytic Activity of NiO Nanoparticles under Visible Light Illumination

In this present study, Nickel oxide (NiO) nanoparticles (NPs) have been synthesized using the hydrothermal method and characterized using powder X-ray Diffraction (XRD), UV-vis and Fourier Transform Infra Red (FTIR) spectroscopies, Scanning Electron Microscopy (SEM), and Energy-Dispersive X-ray (EDX) methods. The result of the characterization indicates that the synthesized sample has a pure cubic phase of NiO with roughly spherical shape morphologies and respective estimated crystallinity and microstrain values of about 78% and 5.1. Test of the photocatalytic activity of the synthesized sample towards the model contaminant dye methylene blue (MB) shows a degradation efficiency of 46% in a period of 2 h under nature sunlight irradiation at natural pH and that the reaction could satisfactorily describe both pseudo-first-order and pseudo-second-order kinetic models. So, this synthesis method may potentially be used for the effective elimination of toxic organic pollutants from water and wastewater over prolonged exposure under natural sunlight without adding any oxidant or adjusting the pH of the reaction medium. Copyright © 2022 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Sun light-assisted enhanced photocatalytic activity and cytotoxicity of green synthesized SnO2 nanoparticles

In this work, SnO2 NPs were green synthesized using Canna indica (C. indica) plant leaves extract and the synthesized powder sample was calcined at different temperatures from 400 to 700 °C. The synthesized sample was characterized using XRD, UV–vis, and FTIR spectra. Furthermore, the photocatalytic activity using Rhodamine B (RhB) dye under visible light illumination of SnO2 nanostructures calcined at different temperatures was tested. RhB was decomposed greater than 97% by all the samples under sunlight irradiation within 30 min while a maximum decomposition of 46% was achieved when exposed to UV lamp irradiation under similar experimental conditions and the reaction was satisfactorily described by pseudo-first-order reaction kinetics. Also, its cytotoxic assessment for Artemia salina (A. salina) was performed.The sample calcined at 600 °C exhibits greater toxicity for A. salina with a survival rate of 45 and 33% for 12 and 24 h exposure to visible light. So, the synthesized SnO2 NPs are promising for the photodegradation of dyes and inhibiting the growth of A. salina animals in saline waters

Photocatalytic Efficiency of Titanium Dioxide for Dyes and Heavy Metals Removal from Wastewater

The hazardous toxicity of dye materials, even in low concentrations, harms ecological systems. It releases a large number of contaminants into the water, resulting as waste water. Dyes prevent the process of photosynthesis by obstructing light passage, lowers the oxygen levels dissolved in the water. Also, a good number of the dyes and heavy metals are carcinogenic and mutagenic to human beings. Heterogeneous photocatalysis is a promising technology for removing organic, inorganic, and microbial pollutants from water and wastewater. It is preferable to other conventional wastewater treatment approaches due to its benefit, such as low cost, environmental friendliness, ability to proceed at ambient temperature and pressure conditions, and to completely degrade pollutants into environmentally safe products with suitable measures. The titanium oxide (TiO2) is one of the most promising material that has gained enormous importance in the field of energy and environmental applications. The unique physicochemical properties of TiO2 make it one of the best candidates among existing photocatalysts. This review provides an overview of strategies employed to augment its catalytic performance as well as the impact of different operational parameters on the removal proficiency of various organic and inorganic pollutants in water and wastewater treatment. Copyright © 2022 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0)