title: Silicon decorated with amorphous cobalt molybdenum sulfide catalyst as an efficient photocathode for solar hydrogen generation.
abstract: The construction of viable photoelectrochemical (PEC) devices for solar-driven water splitting can be achieved by first identifying an efficient independent photoanode for water oxidation and a photocathode for hydrogen generation. These two photoelectrodes then must be assembled with a proton exchange membrane within a complete coupled system. Here we report the preparation of a Si/a-CoMoSx hybrid photocathode which shows impressive performance (onset potential of 0.25 V vs RHE and photocurrent jsc of 17.5 mA cm(-2) at 0 V vs RHE) in pH 4.25 phosphate solution and under simulated AM 1.5 solar illumination. This performance is among the best reported for Si photocathodes decorated with noble-metal-free catalysts. The electrode preparation is scalable because it relies on a photoassisted electrodeposition process employing an available p-type Si electrode and [Co(MoS4)2](2-) precursor. Investigation of the mechanism of the Si/a-CoMoSx electrode revealed that under conditions of H2 photogeneration this bimetallic sulfide catalyst is highly efficient in extracting electrons from illuminated Si and subsequently in reducing protons into H2. The Si/a-CoMoSx photocathode is functional over a wide range of pH values, thus making it a promising candidate for the construction of a complete solar-driven water splitting PEC device.
authors: †Energy Research Institute at Nanyang Technological University (ERI@N), 50 Nanyang Drive, Singapore 637553.|‡Solar Fuels Laboratory, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798.
authors: Yang
authors: Y
authors: Chen
authors: †Energy Research Institute at Nanyang Technological University (ERI@N), 50 Nanyang Drive, Singapore 637553.|‡Solar Fuels Laboratory, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798.
authors: Phong D
authors: PD
authors: Tran
authors: †Energy Research Institute at Nanyang Technological University (ERI@N), 50 Nanyang Drive, Singapore 637553.
authors: Pablo
authors: P
authors: Boix
authors: §Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), 3 Research Link, Singapore 117602.
authors: Yi
authors: Y
authors: Ren
authors: §Institute of Materials Research and Engineering, A*STAR (Agency for Science, Technology and Research), 3 Research Link, Singapore 117602.
authors: Sing Yang
authors: SY
authors: Chiam
authors: †Energy Research Institute at Nanyang Technological University (ERI@N), 50 Nanyang Drive, Singapore 637553.
authors: Zhen
authors: Z
authors: Li
authors: †Energy Research Institute at Nanyang Technological University (ERI@N), 50 Nanyang Drive, Singapore 637553.
authors: Kunwu
authors: K
authors: Fu
authors: ‡Solar Fuels Laboratory, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798.
authors: Lydia H
authors: LH
authors: Wong
authors: ‡Solar Fuels Laboratory, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798.|∥Department of Life Science, Imperial College London, SW7 2AZ London, U.K.
authors: James
authors: J
authors: Barber
keywords: catalysis; hydrogen; molybdenum sulfide; solar fuels; water splitting