Solar Hydrogen Generation by Nanoscale p–n Junction of p-type Molybdenum Disulfide/n-type Nitrogen-Doped Reduced Graphene Oxide

Abstract

Molybdenum disulfide (MoS₂) is a promising candidate for solar hydrogen generation but it alone has negligible photocatalytic activity. In this work, 5–20 nm sized p-type MoS₂ nanoplatelets are deposited on the n-type nitrogen-doped reduced graphene oxide (n-rGO) nanosheets to form multiple nanoscale p–n junctions in each rGO nanosheet. The p-MoS₂/n-rGO heterostructure shows significant photocatalytic activity toward the hydrogen evolution reaction (HER) in the wavelength range from the ultraviolet light through the near-infrared light. The photoelectrochemical measurement shows that the p-MoS₂/n-rGO junction greatly enhances the charge generation and suppresses the charge recombination, which is responsible for enhancement of solar hydrogen generation. The p-MoS₂/n-rGO is an earth-abundant and environmentally benign photocatalyst for solar hydrogen generation.

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