Ni/NiO hybrid nanostructure supported on biomass carbon for visible-light photocatalytic hydrogen evolution

Well-dispersed Ni-based nanocrystals with Ni/NiO hybrid nanostructure are built on cellulose-derived carbon (Ni-C-500), which exhibits outstanding photocatalytic performance in the hydrogen evolution from water. Control experiments confirm that the optimal nickel content in Ni-C-500 is 16 wt% and the optimum calcination temperature is 500 °C. The hydrogen evolution rate on Ni-C-500 in the presence of Eosin Y and triethanolamine (TEOA) reaches 13.5 mmol/g cat /h in the first hour, which is even higher than that on commercial Pt/C catalyst (11.4 mmol/g cat /h). The carbon support facilitates the transfer of photogenerated electrons from photosensitizer to Ni-based nanocrystals, efficiently preventing the recombination of photogenerated electrons and holes during the photocatalytic procedure. Density functional theory (DFT) calculations further demonstrate that the NiO islands on Ni(111) surface facilitate the adsorption of water molecules because of the interaction between the oxygen atom of NiO island and the hydrogen atom of water. Furthermore, produced H ad around NiO island of Ni(111) surface is more easily to form hydrogen on Ni/NiO hybrid nanostructure than on clean Ni(111) surface. Graphical abstract Ni/NiO hybrid nanostructure supported on biomass carbon for visible-light photocatalytic hydrogen evolution