Executive Summary : | The study focuses on sustainable, clean, and ecologically friendly alternative energy sources, specifically photocatalysis of water splitting to produce hydrogen under solar energy. The semiconductor photocatalyst should absorb the most amount of solar spectrum while undergoing the least amount of electron-hole recombination and have the proper band edge potentials. The effective charge carrier transport to the surface active cites depends heavily on the interface/junction between the components of the photocatalyst system. Type-II heterojunction is inferior to Z-scheme photocatalysis due to compromising the catalyst's redox capabilities. The current endeavor aims to select suitable materials for Z-scheme photocatalysis, specifically creating two photocatalysts with a tight band gap and robust HEP and OEP. Metal titanate perovskites' oxynitrides were chosen as HEP photocatalysts due to their ability to adjust opto-electrical characteristics needed for photocatalysis applications. WO3 and MWO4 family were selected as OEP photocatalysts from the visible active semiconductors due to their abundant availability, high surface area, and acceptable band edge potential. The effect of nitride loading temperature, flaws, and other factors essential for understanding the photocatalytic activity of oxynitride perovskites was not thoroughly investigated. The morphology and formed interface play a vital role in the efficient transfer of produced charge carriers onto the surface-active sites with minimal e-h recombination. The goal of this study is to investigate the impact of morphology and interface using various techniques for improved photocatalytic capabilities, such as increased visible-light absorption, decreased electron-hole recombination with tunable band edge potentials, and efficient overall water splitting on oxynitride perovskites tungstate photocatalysts by Z-scheme mechanism. |