Novel visible-light-driven direct Z-scheme WO3/Mn-ZIF-67 heterojunctions with facilitation photocatalytic activity

Abstract

In order to alleviate the problem of water resource pollution, the exploration of visible-light driven excellent photocatalysts is an important issue for worldwide sustainable green energy systems. In this work, a novel binary hybrid nanocomposite WO3/Mn-ZIF-67 heterojunction photocatalyst was prepared through simple template method. It was based on the particular structure and performance of metal-organic framework (MOFs), and the structure of the heterojunction photocatalyst was expressed by SEM, TEM, FT-IR, DRS, XPS, PXRD and EIS. The novel WO3/Mn-ZIF-67 heterostructure showed more efficient photocatalytic properties for Tetracycline (TC) decomposition and hydrogen production than that of WO3 monomer and Mn-ZIF-67 monomer under simulated light, respectively. Owing to the active radical catch and ESR experiments, a rational solid-state Z-model electron migration theory was rendered. Z-model mechanism can neatly be obligated to the raised degradative capacity of the photocatalytic reaction. The wonderful high-efficiency photocatalytic decomposability of heterojunction was mainly due to: (i) the WO3 structure improved dramatically the light absorption efficiency of the photocatalyst. (ii) the doped Mn enhanced the photoelectric properties of ZIF-67. (iii) contact with the close interface between WO3 and Mn-ZIF-67 produced efficient charge separation and migration.