In situ characterization revealing the accelerated hot carrier kinetics for high-performance photocatalysis

The insights into the structure-performance relationship and reaction mechanism of photocatalysts, particularly in realistic reaction conditions, play the key role in understanding the origin of high performance for key energy conversion reactions in photocatalysis. Hot charge carriers with high kinetic energy generated by high-energy photons usually participate in the redox reactions more efficiently than charge carriers relaxed at the band edge of the photocatalyst. Thus, it is of great significance to monitor/regulate the kinetics and lifetime of hot carriers in photocatalysts. Here, we report the novel protonation route to regulate the surface properties of C3N5 nanosheet for optimizing the hot carrier kinetic/lifetime and achieving high-performance photocatalytic evolution of H2O2 (11.04 mmol g-1h-1) and benzaldehyde (25.71 mmol g-1h-1), simultaneously. Six types of in situ characterizations reveal that protonation can help extend the lifetime of hot electron/hole, respectively. Thus, more H2O2 can be generated while much more O2originated active species, e.g., center dot O2-and & sdot;OH, can be generated to efficiently oxidize the benzyl alcohol to generate benzaldehyde. Our research exhibits the great significance of using in situ characterization to reveal the insightful reaction mechanism in realistic conditions in photocatalysis area.