Enhancing photocatalytic H2O2 production with S-type heterojunctions of CeO2 coupled N-vacancy-rich carbon nitride

Artificial photosynthesis for H 2 O 2 production through O 2 reduction is a sustainable and cost-effective technology for the scientific and industrial communities. Metal-free polymeric carbon nitride (CN) is a promising visible-light responsive semiconductive material for photocatalytic H 2 O 2 production. However, its inherently disordered and amorphous structure limits its performance improvement due to high photogenerated carrier complexation and sluggish interlayer charge transfer. Here, we report a high-performance S-type heterojunction, composed of CeO 2 coupled with N -vacancy-rich CN (CeO 2 /Nv-CN), that enhances the photocatalysis of H 2 O 2 production under visible light. The prepared CeO 2 /Nv-CN showed an H 2 O 2 generation rate of up to 69.79 mmol·g −1 ·h −1 , 48.80-fold higher than CN and had an apparent quantum yield of 13.8 % at 400 nm. A synergistic effect among CeO 2 , N -vacancies (Nv) and S-type heterojunction is responsible for such an excellent activity, which increased the O 2 and light absorption sites, built rapid charge diffusion channels, and enhanced two-electron O 2 reduction. This work demonstrates the potential of incorporating nanosized CeO 2 with CN to achieve high-performance photocatalytic H 2 O 2 production, opening new avenues for designing highly efficient polymeric composite photocatalysts for energy conservation.