Interface-Engineered Ni-Coated CdTe Heterojunction Photocathode for Enhanced Photoelectrochemical Hydrogen Evolution.

ABSTRACT: Photoelectrochemical (PEC) water splitting for hydrogen production using the CdTe photocathode has attracted much interest due to its excellent sunlight absorption property and energy band structure. This work presents a study of engineered interfacial energetics of CdTe photocathodes by deposition of CdS, TiO₂, and Ni layers. A heterostructure CdTe/CdS/TiO₂/Ni photocathode was fabricated by depositing a 100-nm n-type CdS layer on a p-type CdTe surface, with 50 nm TiO₂ as a protective layer and a 10 nm Ni layer as a co-catalyst. The CdTe/CdS/TiO₂/Ni photocathode exhibits a high photocurrent density (J_ph) of 8.16 mA/cm² at 0 V versus reversible hydrogen electrode (V_RHE) and a positive-shifted onset potential (E_onset) of 0.70 V_RHE for PEC hydrogen evolution under 100 mW/cm² AM1.5G illumination. We further demonstrate that the CdTe/CdS p-n junction promotes the separation of photogenerated carriers, the TiO₂ layer protects the electrode from corrosion, and the Ni catalyst improves the charge transfer across the electrode/electrolyte interface. This work provides new insights for designing noble metal-free photocathodes toward solar hydrogen development.

SUBMITTER: Jian JX 

PROVIDER: S-EPMC10165602 | biostudies-literature | 2023 May

REPOSITORIES: biostudies-literature