Efficient Nb2O5@g-C3N4 heterostructures for enhanced photocatalytic CO2 reduction with highly selective conversion to CH4

Achieving the goal of carbon neutralization using photocatalytic CO2 reduction has garnered widespread attention. However, rapid photogenerated charge recombination seriously impedes the further improvement of photocatalytic properties. In response, we propose a strategy to solve this limitation by way of constructing a heterojunction. A Nb2O5@g-C3N4 type II heterojunction photocatalyst was developed by a straightforward hydrothermal method. The construction of a heterojunction greatly accelerates the separation of photoinduced charges and increases the photocatalytic activity. As a result, Nb2O5@g-C3N4 (1 : 5) possesses outstanding properties for CO2 reduction under visible light with the production of CH(4 )and CO of about 19.06 and 1.93 mu mol g(-1), respectively. The CH4 selectivity is up to 98.79%. Furthermore, the mechanism of photocatalytic CO2 reduction is revealed in detail based on in situ DRIFTS and photochemical characterization, thus providing guidance for the design of high-performance CO2 photoreduction systems.