Solar water splitting based on semiconductor photoelectrodes is a promising route to convert solar energy into renewable hydrogen fuel. Since the pioneering work of photoelectrochemical (PEC) systems in 1972, a large variety of semiconductors such as oxides, sulfides, phosphides, and silicon have been studied in the context of PEC water splitting configuration. Among them, silicon carbide (SiC) exhibits an excellent energy band structure that straddles the water redox potentials. In particular, cubic SiC (3C‐SiC), with a suitable bandgap of 2.36 eV, is favorable for visible sunlight absorption. Recently, 3C‐SiC has attracted much interest in PEC water splitting. In this review, the progress, challenges, and prospects of using SiC for PEC water splitting are summarized.

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.

Minisci reaction of heteroarenes and unactivated C(sp ³ )–H alkanes via a photogenerated chlorine radical from FeCl ₃ and seawater.