Construction of 2D/2D Z-scheme MnO2-x/g-C3N4 photocatalyst for efficient nitrogen fixation to ammonia
Limin Yu, Zhao Mo, Xianglin Zhu, Jiujun Deng, Fan Xu, Yanhua Song, Yuanbin She, Huaming Li, Hui Xu
Abstract
Reducing nitrogen to ammonia with solar energy has become a wide concern when it comes to photocatalysis research. It is considered to be one of the more promising alternate options for the conventional Haber–Bosch cycle. Herein, 2D g-C3N4 composites with modifying ultrathin sheet MnO2-x were prepared and used as nitrogen fixation photocatalyst. With the assistance of the nature of MnO2-x, the generation rate of NH3 reached 225 μmol g−1 h−1, which is more than twice over the rate of pristine 2D g-C3N4 (107 μmol g−1 h−1). The presence of ultrathin sheet MnO2-x shortens the gap of the carriers to the surface of photocatalyst. Thus the speed of electron transfer gets increased. Besides, the construction of Z-scheme heterojunction boosts the separation and migration of photogenerated carriers. As a result, the nitrogen reduction reaction (NRR) performance gets enhanced. The work may provide an example of promoting the NRR performance of non-metallic compound.