Photocarving nitrogen vacancies in a polymeric carbon nitride for metal-free oxygen synthesis

Photocatalytic water splitting necessitates robust cocatalysts to accelerate the oxygen evolution reaction (OER). However, most OER cocatalysts are based on noble metal oxides. Besides, the loose interface between semiconductor and cocatalyst results in inefficient charge transfer. The fabrication of photocatalysts with integrated light-harvesting and catalytic centers for OER is therefore desired. Herein, we provide a photocarving strategy to create nitrogen vacancies (NVs) on polymeric carbon nitride (PCN). It is confirmed that the embedded NVs can function as active sites to catalyze OER, while promoting the transfer of the photogenerated charge for OER. As a result, PCN-NVs without any extra noble-metal cocatalyst assistance exhibit an enhanced oxygen evolution rate compared with the pristine PCN. Additionally, the PCN obtained from other precursors can also be engineered by this photocarving method, while promoting oxygen photosynthesis. This work provides an avenue to design light-transducers with combined light-harvesting and catalytic configurations for oxygen synthesis chemistry.