Photofixation of atmospheric nitrogen to ammonia with a novel ternary metal sulfide catalyst under visible light

Abstract

A novel ternary metal sulfide photocatalyst Mo_0.1Ni_0.1Cd_0.8S was prepared for photofixation of atmospheric nitrogen to ammonia under visible light. Characterization results indicate that the obtained catalyst is Mo and Ni co-doped CdS with many sulfur vacancies, not a mixture of MoS₂, NiS and CdS. The sulfur vacancies on Mo_0.1Ni_0.1Cd_0.8S not only serve as active sites to adsorb and activate N₂ molecules but also promote interfacial charge transfer from Mo_0.1Ni_0.1Cd_0.8S to N₂ molecules, thus significantly improving the nitrogen photofixation ability. The concentration of sulfur vacancies plays a significantly important role in the N₂ photofixation ability. A possible mechanism was proposed.