Pt-Ni contact engineering in carbon nitride based photocatalysts for hydrogen production

Abstract

The effect of a binary PtNi co-catalyst supported on graphitic carbon nitride nanosheets is studied in the photo-production of hydrogen from methanol:water mixtures. The physicochemical analysis provides evidence that the carbon nitride support allows the formation of highly dispersed PtNi nanoparticles with an average composition of Pt 85 % Ni 15 %. The binary system outperforms the monometallic Pt and Ni counterparts and renders an extraordinary quantum efficiency of 8.8 % for hydrogen photo-production. The formation of a PtNi alloy, with a Pt-enriched surface and electronic properties influenced by the heterometallic contact, provides high and stable activity, mostly as a consequence of the effects that the co-catalyst exerts on the charge carrier handling capability of the solid.