High performance n+p-Si/Ti/NiSxOy photocathode for photoelectrochemical hydrogen evolution in alkaline solution

Silicon, as a promising semiconductor for fabricating photocathode toward photoelectrochemical hydrogen evolution reaction (PEC-HER), should be improved in light harvesting ability and catalytic kinetics to obtain high PEC performance. Herein, a novel amorphous Nickel Oxysulfide (NiSxOy) film is effectively integrated with a Ti protected n(+)p-Si micropyramid photocathode by the electrodeposition method. The fabricated n(+)p-Si/Ti/NiSxOy photocathode exhibits excellent PEC-HER performance with an onset potential of 0.5 V (at J = -0.1 mA/cm(2) ), a photocurrent density of -26 mA/cm(2) at 0 V vs. RHE, and long term stability of six hours in alkaline solution (pH approximate to 14). The synergy of unique n(+)p-Si micropyramid architectures (omnidirectional broadband light harvesting ability), novel amorphous NiSxOy catalyst (high HER electrocatalytic activity and good optical transparency) results in the high performance of n(+)p-Si/Ti/NiSxOy . This work offers a novel strategy for effectively integrating electrocatalysts with semiconductor to design efficient photoelectrode toward PEC water splitting. (C) 2018 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.