Rapid flame induced dual-metal doping on WO3 electrode for boosting photo-electrochemical water oxidation

Abstract

A bidirectional co-doping of transition metal Fe and post-transition metal Sn on WO3 photoanode via a facile one step flame-doping process demonstrates the challenging amelioration of both thermodynamic charge migration and surface catalytic kinetics, achieving high-efficient photoelectrochemical (PEC) water oxidation reaction in a neutral pH. The direct flamethrower with rapid thermal flux effectively induces the bidirectional doping of Fe3+ and Sn4+ into WO3 without damaging its nanostructure and fluorine-doped tin oxide glass substrate. From the synergetic effect of the dual-metal doping, the photoinduced charge migration and the surface water oxidation kinetics are effectively ameliorated. As a result, the Fe/Sn co-doped WO3 photoanode shows significantly enhanced PEC response with 6.16-fold higher photocurrent density performance at 1.23 VRHE than bare WO3. This work highlights the facile metal atom co-doping method without affecting intrinsic properties of photoanode and substrate for boosting the PEC water splitting performance and solar fuel production.