Optical bandgap variation and photo-Fenton property evolution in Fe-doped Bi2YO4Cl

Abstract

The current study addresses the existing research gap on the effects of transition metal doping in layered Bi2YO4Cl and searches for a new visible light photocatalyst in the bismuth-based oxychloride system. The extent of Fe substitution in place of Y in Bi2YO4Cl and its consequences on the structure, optical, and catalytic properties have been examined by synthesizing the samples using a solution combustion method. Nearly 20 mol% of Fe could be introduced in a monophasic layer structural arrangement. The Fe-containing samples have also been characterized by electron microscopic and vibrational spectroscopic techniques. The optical absorbance shifted to the visible region with the Fe inclusion, and the bandgap decreased from 2.40 eV (pristine) to 1.77 eV (20 mol % Fe-substituted). XPS analysis of the Fe-containing sample indicated that Fe existed majorly in the III oxidation state with traces of the II oxidation state. The photo-Fenton function of Bi2Y1-xFexO4Cl (x = 0.10 and 0.20) for the oxidative degradation of RhB and MB dye molecules under LED illumination has been demonstrated. From scavenger experiments, OH• radicals and holes have been identified as the reactive oxidation species (ROS) involved in these reactions. The catalyst showed recyclability and structural integrity.