Co-doped amorphous MoSx supported on CuO/CM (Cu mesh) with enhanced photocatalytic activity for ammonia synthesis

Abstract

As one of the world's most significant industrial synthetic chemicals, ammonia has critical applications in many fields. Mo-based catalyst has an excellent effect on photocatalytic nitrogen fixation. Compared with crystalline molybdenum sulfide, low crystalline or amorphous molybdenum sulfide has rich unsaturated defects to improve the photocatalytic activity. Therefore, we used CuO/CM (Cu mesh) as the substrate and a simple electrochemical deposition method to load amorphous MoSx doped with different contents of Co on CuO/CM and successfully synthesized a thin film heterojunction photocatalyst. At the same time, we fabricated a gas-liquid-solid three-phase photocatalytic reactor to evaluate the catalytic activity of the catalyst. Compared with the powder catalyst reported in the literature, because the catalytic reaction of the three-phase gas-liquid-solid three-phase reactor occurs at the gas-liquid interface, the film catalyst can also absorb sufficient N2 in the gas phase while contacting the liquid proton source (water). It can effectively enhance photocatalytic nitrogen fixation efficiency. The constructed film photocatalyst showed good photocatalytic performance and stable structure under the 350 W simulated light source. While exploring the catalyst structure, the photocatalytic effect of the catalyst was evaluated. When the molar ratio of Mo and Co is 1:0.9, the photocatalyst efficiency shows the high photocatalysis at a rate of 1.062 mg·L−1 for 4 h. Compared with pure CuO / CM and MoSx / CuO / CM, the NH3 yield of the catalyst was increased by 7.86 and 7.52 times, respectively. In addition to N2, no other N sources were introduced during the reaction, which ensured the accuracy of the experimental results.