Highly Efficient Visible Light Active Doped ZnO Photocatalysts for the Treatment of Wastewater Contaminated with Dyes and Pathogens of Emerging Concern

Abstract

Water is obligatory for sustaining life on Earth. About 71% of the Earth’s surface is covered in water. However, only one percent of the total water is drinkable. The presence of contaminants in wastewater, surface water, groundwater, and drinking water is a serious threat to human and environmental health. Their toxic effects and resistance towards conventional water treatment methods have compelled the scientific community to search for an environmentally friendly method that could efficiently degrade toxic contaminants. In this regard, visible light active photocatalysts have proved to be efficient in eliminating a wide variety of water toxins. A plethora of research activities have been carried out and significant amounts of funds are spent on the monitoring and removal of water contaminants, but relatively little attention has been paid to the degradation of persistent water pollutants. In this regard, nanoparticles of doped ZnO are preferred options owing to their low recombination rate and excellent photocatalytic and antimicrobial activity under irradiation of solar light. The current article presents the roles of these nanomaterials for wastewater treatment from pollutants of emerging concern.

Nd-Doped ZnO Nanostructures with Enhanced Photocatalytic Performance for Environmental Protection

“…Nanostructured oxide semiconductor materials have been intensively studied in recent years due to various commercial applications, including in photocatalysts, batteries, self-cleaning surfaces, fabrics, photovoltaics, antiseptic patches, ink and paints, and so on [ 1 ]. Zinc oxide (ZnO) is considered one of the most important n-type semiconductors owing to its outstanding performance and numerous applications (sensors, nanomedicine, optoelectronics, energy, and environment) [ 2 ].…”

Electrochemical detection and removal of brilliant blue dye via photocatalytic degradation and adsorption using phyto-synthesized nanoparticles

“…The following formula was employed to estimate the band gap value. 20 ( αhυ ) n = A ( hυ − E g )where, “ A ” denotes the proportionality constant, the symbol “ h ” is the Planck's constant, “ ν ” symbolizes the frequency of photons, “ α ” signifies the absorption coefficient, and “ E g ” refers to the band gap energy. The value of the parameter “ n ” for direct transition band gaps is 2, while the value for an indirect band gap is 1/2.…”

Green Synthesis of CuO-TiO2 Nanoparticles for the Degradation of Organic Pollutants: Physical, Optical and Electrochemical Properties

“…Despite this, contaminants such as dyes and antibiotics are being detected in natural water sources, and the number of contaminants detected has increased in recent years as new emerging pollutants are reported each year [4,5]. The textile sector contributes significantly to water pollution in the environment by dumping dye-bearing waste effluents [6][7][8][9]. Even at low concentrations, the presence of these dyes (which can be anionic, cationic, or non-ionic) in water is highly apparent and undesired [10].…”