A template co-pyrolysis strategy towards the increase of amino/imino content within g-C3N4 for efficient CO2 photoreduction

Photocatalytic CO 2 reduction reaction (CO 2 RR) is an effective mean to address the current environmental and energy issues. As a kind of typical photocatalyst, g-C 3 N 4 possesses lots of advantages (i.e . , facile synthesis, visible-light response, and high stability) in CO 2 reduction. However, the poor capacity of CO 2 capture and rapid recombination of photo-generated electron and hole, both hinder the further development of g-C 3 N 4 for CO 2 RR. Herein, we developed a template co-pyrolysis strategy to prepare C–NH x -rich ( x  = 1 or 2) g-C 3 N 4 , to increase the CO 2 binding and the subsequent photocatalytic CO 2 reduction efficiency. Specifically, organic molecules with multiple imino groups were used as additives to co-pyrolyze with urea. These additives can act as templates to facilitate the formation of g-C 3 N 4 with abundant C–NH x groups, which effectively improved the capacity of CO 2 capture. Meanwhile, the capacity of light absorption and the separation of photo-generated electron and hole were also optimized. As a result, the obtained C–NH x -rich g-C 3 N 4 showed greatly enhanced photocatalytic activity for CO 2 RR, over 74-fold higher than that of g-C 3 N 4 conventionally prepared. This work provides a new avenue for optimizing the g-C 3 N 4 -based photocatalysts for CO 2 RR.