Construction of hierarchical ZnS@ZnO secured from metal – organic framework- ZnS@ZIF-8 for enhanced photoreduction of CO2

Abstract

BackgroundThe CO2 photochemical conversion reaction has received attention under mild conditions. The CO2 photoreduction to CH3OH has become an approach of “one stone to kill two birds” since it provides the probability to complete the carbon circle and create invaluable products in a rotational economy. MethodOne-pot synthesis of porous ZnS@ZnO was developed with a large surface area of 1530 m2/g by Zn(NO3)2, Na2S and 2-methylimidazole as precursors. The obtained Pt/ZnS@ZnO heterostructure was evaluated for photoconversion of CO2 to CH3OH through visible light illumination. Significant findingsThe most photoactive 1%Pt/ZnS@ZnO showed a CH3OH formation of 1402 µmol g−1 after 9 h, which was enhanced 11.2- and 10.97- times larger than ZnO and ZnS@ZnO. The CH3OH formation rate over 1%Pt/ZnS@ZnO was promoted 12 times greater than ZnO and ZnS@ZnO heterostructure. The synthesized photocatalyst exhibited high stability and durability after five repeated cycles within 45 h. The superior CO2 reduction over Pt/ZnS@ZnO could be imputed to i) the construction of heterojunction between ZnS and ZnO, which enhanced the charge carriers-migration process and promoted the charge carriers lifetime; ii) the different energy levels led the high oxidative ability of the adsorbed OH‾ surface and hence facilitates the catch of photoinduced holes.