Irradiation regulates the size of Pt nanoparticles on Au@MnO2 nanosheets for electrocatalytic hydrogen evolution

Abstract

Regulating the size of noble metals over oxide nanosheets has been attracting great attention in the fields of electrochemistry and catalysis. The photodeposition process is green, mild and controllable but is limited to loading noble metals onto semiconductors or metals with localized surface plasmon resonance effect. In this study, we proposed to use the photoinduced LSPR effect of Au NPs to load and adjust the size of Pt NPs on MnO₂ nanosheets. The sizes of Pt could be easily adjusted using different light sources. This strategy could be expanded to Ag/Au@MnO₂. Electrocatalytic hydrogen evolution reaction (HER) was used as a model reaction to study the size effect of Pt on Au@MnO₂ nanosheets. The optimized sample Pt-520/Au@MnO₂ with small size has a lower initial potential than that of commercial Pt/C catalysts, while the mass activity of Pt is about 12.9 times higher than that of commercial Pt/C under 50 mV overpotential. This study provides an alternative route for controlling the size of metals on metal oxides beyond semiconductors via the photoinduced LSPR effect of noble metals.