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 V_RHE 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.

Keywords

Flame treatment / dual metal co-doping / oxygen evolution reaction / photoelectrochemical reaction / water splitting

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