Crystal phase engineering Zn0.8Cd0.2S nanocrystals with twin-induced homojunctions for photocatalytic nitrogen fixation under visible light

Abstract Newly developed photocatalysts usually focus on structuring active sites, for enhancing chemical adsorption and reducing activation energy barrier in photocatalysis nitrogen fixation. However, lots of photocatalysts suffer from electron-hole pairs’ recombination in the bulk or on the surface during transportation. Herein, twinned Zn0.8Cd0.2S nanocrystals were successfully applied to photocatalytic nitrogen fixation, affording an ammonia production rate of 66.91 μmol g-1 h-1 under visible light with an AQE of 3.77% at 420 nm, which were 17-fold and 3-fold higher than the activities of CdS and ZnS, respectively. The inner homojunction enhanced carriers’ transportation, and improved electrons density on zinc blend segment, which could facilitate adsorption of nitrogen and ·H gaining, finally, the nitrogen activation and reduction proceeded through the six electrons reduction process on (111) facets. These results confirm that twinned Zn0.8Cd0.2S nanocrystal is a kind of promising new photocatalyst for solar-driven nitrogen reduction to ammonia.