Defect-designed Mo-doped BiVO_(4)photoanode for efficient photoelectrochemical degradation of phenol

The monoclinic scheelite BiVO_(4)has impressive properties such as a narrow energy band gap,exceptional stability,and extended absorption in visible light,making it a suitable photoanode.Nevertheless,the BiVO_(4)material encounters challenges such as the high recombination rate of photogenerated electronhole pairs and poor photoelectron conductivity,which limits photocatalytic activity.To address this problem,we developed Mo-doped BiVO_(4)films on FTO substrates for photoelectrocatalytic degradation of phenol.When exposed to visible light,the Mo-BiVO_(4)film attained a 70%degradation of phenol in 120 min with a 1.2 V vs.Ag/AgCl bias—a 3.7 times improvement from pristine BiVO_(4).Mo-doping facilitates better migration and separation of electron-hole pairs and increases the concentration of photogenerated carriers,leading to an upward shift of the valence band potential direction,and an improvement in oxidation capacity.Furthermore,density-functional theory(DFT)calculations were used to explain how Modoping with BiVO_(4)improves the adsorption energy to phenol degradation intermediates,emphasizing its effectiveness in promoting phenol degradation.Therefore,with the inclusion of DFT calculations,this work provides a more comprehensive understanding of the mechanism underlying the enhancement of photocatalytic activity by Mo-doped BiVO_(4),which is crucial information for the further development of effective and efficient photoanodes.