Elucidating semiconducting properties and photocatalytic performance of surface-decorated ▫$BiVO_4$▫ for the removal of contaminants of emerging concern

Photocatalysis has been shown to be a promising and ecofriendly approach to the removal of contaminants of emerging concern (CECs). However, preventing the recombination of photogenerated charge carriers and achievement of suitable band edge positions are still major challenges to ensuring better performance. Herein, we report the preparation of surface-decorated BiVO$_4$ with both a noble metal (Ag) and transition metal (Fe). The structural, morphological, and semiconducting features of the material were examined employing various techniques (XRD, SEM, UV-DRS, PL, and photoelectrochemical tests). The band gap of surface-modified BiVO$_4$ is slightly narrower compared to pristine material, which is further validated by HOMO-LUMO gaps obtained through theoretical modeling approaches. The recombination of photogenerated charges was successfully reduced in the case of Ag–Fe–BiVO$_4$, as proven by lower PL intensity and increased current density. The comparative photocatalytic degradation of the CECs ciprofloxacin (CIP) and perfluorooctanoic acid (PFOA) was conducted employing pristine BiVO$_4$ and its two surface-modified analogues (Ag–BiVO$_4$, and Ag–Fe–BiVO$_4$) under solar light. Ag–Fe–BiVO$_4$ was shown to be the most efficient