The fabrication of graphitic carbon nitride hollow nanocages with semi-metal 1T' phase molybdenum disulfide as co-catalysts for excellent photocatalytic nitrogen fixation

Improving the efficiency of photogenerated carrier separation is essential for photocatalytic N2 fixation. Herein, the 2D semi-metal 1T'-MoS2 was uniformly distributed in g-C3N4 nanocages (CNNCs) by a hydrothermal method, and the 1T'-MoS2/CNNC composite was obtained. 1T'-MoS2 as a co-catalyst can promote the transfer of electrons, improve the separation efficiency of photogenerated carriers, and also increase the number of effective active sites. In addition, the unique nanocage morphology of CNNCs is conducive to the scattering and reflection of incident light and improves the light absorption capacity. Therefore, the optimized 1T'-MoS2/CNNC composite (5 wt%) shows a significantly improved photocatalytic N2 fixation rate (9.8 mmol L-1 h-1 g-1) and good stability, which is significantly higher than pure CNNCs (2.9 mmol L-1 h-1 g-1), Pt/CNNC (8.2 mmol L-1 h-1 g-1) and Pt/g-C3N4 nanosheet (CNNS, 6.3 mmol L-1 h-1 g-1). This work guides guidance for the design of green and efficient N2 fixation photocatalysts.