Construction of 2D/2D Z-scheme MnO2-x/g-C3N4 photocatalyst for efficient nitrogen fixation to ammonia

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 mu mol g(-1) h(-1), which is more than twice over the rate of pristine 2D g-C3N4 (107 mu mol 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. (C) 2021, Institute of Process Engineering, Chinese Academy of Sciences. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co., Ltd.

Automated summary

2D g-C3N4 composites with modifying ultrathin sheet MnO2-x were prepared and used as nitrogen fixation photocatalyst, leading to an increased NH3 generation rate. The presence of ultrathin sheet MnO2-x shortened the gap of the carriers to the surface of photocatalyst, improving the speed of electron transfer, while the construction of Z-scheme heterojunction boosted the separation and migration of photogenerated carriers, enhancing the nitrogen reduction reaction (NRR) performance.