Facet Engineering-Induced Construction of Ni2P/ZnIn2S4 Heterostructures for Boosted Photocatalytic CO2 Reduction.

Facet engineering was realized to enhance the CO2 photoreduction performance of the Ni2P/ZnIn2S4 heterostructure, in which the commonly exposed (1 0 2) face of ZnIn2S4 was converted to the (1 0 1) face due to the unique properties of the phosphide. The variation in the crystal plane strengthened the intense interfacial contact between Ni2P and ZnIn2S4, resulting in the promotion of utilization and absorption efficiency for incident light and boosting the surface reaction rate. Combined with the significant metallicity of Ni2P, inhibited recombination and strengthened transfer efficiency were achieved, leading to an obvious enhancement of photoreduction activity over Ni2P/ZnIn2S4 compared to pure samples. In particular, the optimal NZ7 composite (the mass ratio of Ni2P to ZnIn2S4) reached 68.31 µmol h-1 g-1 of CH4, 10.65 µmol h-1 g-1 of CH3OH, and 11.15 µmol h-1 g-1 of HCOOH. The mechanism of the CO2 photoreduction process was elucidated using ESR and in situ DRIFTS techniques.