1D/2D heterojunctions of SnS2@MoO3 as an efficient and robust catalyst for boosting the visible photoelectric nitrogen fixation ability

Abstract

In this work, a novel SnS2@MoO3 composite catalyst was designed as the photocathode for PEC to catalytic conversion of nitrogen into ammonia under ambient conditions for the first time. The composite catalyst shows high yield, high stability and high product selectivity by taking advantage of not only photocatalysis but also electrocatalysis mechanism. The best nitrogen fixation performance was 30.04 μg h−1 mg−1 (−0.7 V) and the best Faraday efficiency was 13.41% (−0.6 V) at room temperature and atmospheric pressure. Compared to pure MoO3 and SnS2, the nitrogen fixation performance is improved by 2.3 times and 4.6 times, and the Faraday efficiency is enhanced by 2.0 times and 3.5 times, respectively. The double layer capacitance of the heterojunction is 1.5 times that of SnS2 and 1.7 times that of MoO3 according to linear analysis, indicating that the composite has a higher electrochemically active area than SnS2 and MoO3. It can be concluded that the photoelectric synergistic effect between SnS2 and MoO3 further promote electron transfer under the light and electric conditions and exhibit higher nitrogen fixation catalytic performance. The strong stability in both photoelectric catalytic performance and crystal structures was also confirmed in the SnS2@MoO3 composite.