Engineering single Pt Atoms on hybrid amorphous/crystalline CoFe layered double hydroxide accelerates the charge transfer for solar water splitting

Abstract

Owing to the sluggish kinetics suppressing the oxygen evolution reaction, developing single atoms (SAs) catalyst oxygen evolution reaction catalysts on photoelectrodes is challenging for accelerating charge separation and transfer on photoelectrochemical water splitting. Herein, we elaborately demonstrate the decoration of platinum SAs on hybrid crystalline/amorphous CoFe LDH, and assess the role of SAs on the photogenerated charge carrier separation and transport of photoelectrode. The crystalline/amorphous CoFe LDH is capable of embedding the platinum SAs in its structure by modulating the electronic structure. The single atoms platinum in catalyst enables the effective charge transfer and suppress the charge recombination of the BiVO4 photoelectrode. The SAs Pt/AC-CoFe catalyst delivers an overpotential of 230 mV at 10 mA cm−2, obviously lower than those of AC-CoFe without the introduction of SAs Pt. The SAs Pt/AC-CoFe/BiVO4 exhibits an excellent PEC performance, a current density of 5.14 mA cm−1 obtained at 1.23 VRHE in 1 M KBi under one sun illumination with a stability of 20 h. This work proposes a rational design of single atoms catalysts decorated on semiconductors and reveals the potential of the single atoms to boost charge carrier kinetics.