Hierarchical p-BiOI/n-BiPO4 heterojunction nanocomposite with enhanced visible-light photocatalytic desulfurization of thiophene under mild conditions

Here, we report the fabrication of hierarchical BiOI/BiPO4 nano/microspheres by co-precipitation-refluxing method. The reaction time, reflux temperature and amino acid kind were optimized to form hierarchical microspheres. The BiOI/BiPO4 microspheres were used as novel and strong photocatalyst for the oxidative desulfurization of thiophene under simulated solar light. The photodesulfurization results demonstrated that the p-n heterojunction BiOI/BiPO4 nanocomposites have better photocatalytic desulfurization performance (similar to 95%) than single BiOI or BiPO4 structures. The superior photocatalytic activity of BiOI/BiPO4 heterostructure can be attributed to the powerful visible-light absorption, unique hierarchical structures, high specific surface area, low recombination and high separation rates of electron-hole pairs due to the as-formed p-n heterojunctions. Moreover, we proposed a photocatalytic oxidation mechanism based on the active species scavenging, which revealed that the generation of O-center dot(2)- and h(+) species are absolutely essential for the photocatalytic desulfurization process. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.