Incorporating nitrogen-doped graphene oxide dots with graphene oxide sheets for stable and effective hydrogen production through photocatalytic water decomposition

This study proposes incorporating nitrogen-doped graphene oxide dots (NGODs) with graphene oxide (GO) sheets to form a stable and effective NGOD:GO composite for photocatalytic H-2 production through water splitting under visible light illumination. Although Pt-deposited NGOD catalysts were active in the photocatalytic H-2 production reaction, they were only moderately stable. Introducing GO sheets in light-absorbing NGODs effectively mediated the transfer of photogenerated electrons from the NGODs to the GO sheets. This vectorial electron transfer, confirmed by a photoluminescence spectroscopy analysis, led to the relocation of the reaction sites from the NGODs to the GO sheets, protecting the NGODs from attack by reaction intermediates. Moreover, the GO sheets acted as an electron sink, facilitating charge separation in the NGODs. When 3 wt% Pt was deposited on the developed NGOD:GO catalyst, the catalyst steadily catalyzed H-2 production from a 10 vol% aqueous solution of triethanolamine under visible light illumination for 96 h, unlike a NGOD catalyst that exhibited an activity decay of 50% within 96 h. The apparent quantum yield of H-2 under 420-nm light irradiation was 16.0%, demonstrating the high activity of the NGOD:GO catalyst (C) 2015 Elsevier B.V. All rights reserved.