A review on photocatalytic remediation of environmental pollutants and H2 production through water splitting: A sustainable approach

Rapid urbanization, industrialization, and economic growth has brought in its wake environmental degradation and concern for energy security. Recalcitrant organic pollutants in water and air matrices are difficult to be treated by conventional methods. Photocatalysis, one of the several advanced oxidation processes (AOPs), generates highly reactive hydroxyl radicals and other strong oxidants, which are capable of mineralizing recalcitrant pollutants into harmless substances. This process is based on the typical electronic structure of certain metal oxide semiconductors, which are excited into producing electron-hole pairs upon irradiation. Photocatalysis is effective in degradation and mineralization of strongly recalcitrant pollutants like synthetic dyes, biocides, and endocrine disruptive substances (EDCs). The technology has promised in lignin degradation as well as biological decontamination. It can purify the air by destroying pathogens, volatile organic compounds (VOCs), and odors. It is effective in treating wastewater containing explosive substances like RDX and TNT and pharmaceuticals including antibiotics. Photocatalytic water splitting to produce hydrogen is another extremely important application of this technology, which can store energy from intermittent sources of renewable energy. The paper approached scientific and technical knowledge along with trending information for researchers, scientists, and engineers in the field of photocatalysis. A critical review of recent literature, articles have been made, some general area has been spotted which needs more research in the near future. This survey will enhance the understanding of researchers in the field of degradation of recalcitrant by using photocatalysis. Review sets focus on TiO2 based photocatalytic mechanistic details implication and future outcomes are also effectively discussed. (c) 2020 Elsevier B.V. All rights reserved.