title: Rapid Construction of ZnO@ZIF-8 Heterostructures with Size-Selective Photocatalysis Properties.
abstract: To selectively remove heavy metal from dye solution, inspired by the unique pore structure of ZIF-8, we developed a synthetic strategy for rapid construction of ZnO@ZIF-8 heterostructure photocatalyst for selective reduction of Cr(VI) between Cr(VI) and methylene blue (MB). In particular, ZnO@ZIF-8 core-shell heterostructures were prepared by in situ ZIF-8 crystal growth using ZnO colloidal spheres as template and zinc source within 8-60 min. The shell of the resulting ZnO@ZIF-8 core-shell heterostructure with a uniform thickness of around 30 nm is composed of ZIF-8 crystal polyhedrons. The concentration of organic ligand 2-methylimidazole (Hmim) was found to be crucial for the formation of ZnO@ZIF-8 core-shell heterostructures. Different structures, ZnO@ZIF-8 core-shell spheres and separate ZIF-8 polyhedrons could be formed by altering Hmim concentration, which significantly influences the balance between rate of Zn(2+) release from ZnO and coordinate rate. Importantly, such ZnO@ZIF-8 core-shell heterostructures exhibit size-selective photocatalysis properties due to selective adsorption and permeation effect of ZIF-8 shell. The as-synthesized ZnO@ZIF-8 heterostructures exhibited enhanced selective reduction of Cr(VI) between Cr(VI) and MB, which may find application in the dye industry. This work not only provides a general route for rapid fabrication of such core-shell heterostructures but also illustrates a strategy for selectively enhanced photocatalysis performance by utilizing adsorption and size selectivity of ZIF-8 shell.
authors.affiliation: Anhui Key Laboratory of Advanced Building Materials, Key Laboratory of Functional Molecule Design and Interface Process, School of Materials and Chemical Engineering, Anhui Jianzhu University , Hefei, 230601, P. R. China.|Department of Chemical Engineering, Monash University , Clayton, Victoria 3800, Australia.
authors.forename: Xianbiao
authors.initials: X
authors.lastname: Wang
authors.affiliation: Anhui Key Laboratory of Advanced Building Materials, Key Laboratory of Functional Molecule Design and Interface Process, School of Materials and Chemical Engineering, Anhui Jianzhu University , Hefei, 230601, P. R. China.
authors.forename: Jin
authors.initials: J
authors.lastname: Liu
authors.affiliation: Department of Chemical Engineering, Monash University , Clayton, Victoria 3800, Australia.
authors.forename: Sookwan
authors.initials: S
authors.lastname: Leong
authors.affiliation: Department of Chemical Engineering, Monash University , Clayton, Victoria 3800, Australia.
authors.forename: Xiaocheng
authors.initials: X
authors.lastname: Lin
authors.affiliation: Department of Chemical Engineering, Monash University , Clayton, Victoria 3800, Australia.
authors.forename: Jing
authors.initials: J
authors.lastname: Wei
authors.affiliation: Department of Chemical Engineering, Monash University , Clayton, Victoria 3800, Australia.
authors.forename: Biao
authors.initials: B
authors.lastname: Kong
authors.affiliation: Anhui Key Laboratory of Advanced Building Materials, Key Laboratory of Functional Molecule Design and Interface Process, School of Materials and Chemical Engineering, Anhui Jianzhu University , Hefei, 230601, P. R. China.
authors.forename: Yongfei
authors.initials: Y
authors.lastname: Xu
authors.affiliation: Department of Chemical Engineering, Monash University , Clayton, Victoria 3800, Australia.
authors.forename: Ze-Xian
authors.initials: ZX
authors.lastname: Low
authors.affiliation: Department of Chemical Engineering, Monash University , Clayton, Victoria 3800, Australia.|College of Chemical Engineering, Nanjing Forestry University , Nanjing, 210037, P. R. China.
authors.forename: Jianfeng
authors.initials: J
authors.lastname: Yao
authors.affiliation: Department of Chemical Engineering, Monash University , Clayton, Victoria 3800, Australia.
authors.forename: Huanting
authors.initials: H
authors.lastname: Wang
keywords: ZnO@ZIF-8; heterostructure; photocatalysis; rapid construction; size-selective