Anchoring Ni2P on the UiO-66-NH2/g-C3N4-derived C-doped ZrO2/g-C3N4 Heterostructure: Highly Efficient Photocatalysts for H-2 Production from Water Splitting

Constructing heterostructured photocatalysts and depositing an appropriate co-catalyst to facilitate charge separation are crucial steps to improve photocatalytic H-2 evolution from water splitting. Herein, we reported the synthesis of C-doped ZrO2/g-C3N4/Ni2P (C-ZrO2/g-C3N4/Ni2P) composite based on the UiO-66-NH2 material for photocatalytic H-2 production under visible-light irradiation. The optimal H-2 evolution rate over C-ZrO2/g-C3N4/20%Ni2P was 10.04mmolg(-1)h(-1), which was more than 10times higher than that of C-ZrO2/20%Ni2P (0.90mmolg(-1)h(-1)). The apparent quantum yield of C-ZrO2/g-C3N4/20%Ni2P at 420nm reached 35.5%. A detailed analysis of the action mechanism revealed that the improved photocatalytic activity could be ascribed to the highly efficient spatial separation of the photoinduced charge carriers between C-ZrO2 and g-C3N4, as a result of the tightly bound structure of C-ZrO2/g-C3N4/20%Ni2P and its staggered band energy. The presence of the Ni2P co-catalyst accelerates the surface reaction as well. This work demonstrates that anchoring appropriate co-catalysts onto a metal-organic framework (MOF)/g-C3N4-derived metal oxide/g-C3N4 hybrid is an effective way to obtain heterostructured photocatalysts for H-2 production.