Fabrication of WO_2.72/UiO‐66 nanocomposites and effects of WO_2.72 ratio on photocatalytic performance: judgement of the optimal content and mechanism study

Abstract

BACKGROUND Recently, hybrid nanocomposites based on metal–organic frameworks (MOFs) and inorganic nanomaterials have been actively investigated as a potential technology for solving the environmental pollution problems. However, to our knowledge, there have been no composites of WO2.72 and MOFs reported until now. In this study, highly dispersed WO2.72 nanorods were first grown in situ upon UiO‐66 through a hydrothermal process. RESULTS The optimal content of the WO2.72 (30 wt%) could be intuitively judged by field emission scanning electron microscopy. The degradation efficiency of methyl orange (MO) in photocatalysis with 30 wt% WO2.72 loading exhibited better photocatalytic activity than bare UiO‐66, WO2.72 and other WO2.72 loadings. The enhancement of photocatalytic activity over hybrid WO2.72/UiO‐66 can be ascribed to the difference of conduction band between WO2.72 and UiO‐66, which could cause the photoelectron inject to the WO2.72 from UiO‐66, and the lone pair electrons of –OH and –COOH groups of the UiO‐66, which not only repel excited electrons but also attract photogenerated holes. CONCLUSIONS The enhanced separation of photoexcited carriers between WO2.72 and UiO‐66 led to the enhancement of photocatalytic activity. The photocatalytic reaction mechanism for MO treatment was also studied. © 2018 Society of Chemical Industry

Recent advances in MOF-based photocatalysis: environmental remediation under visible light

“…26C) as well as good stability for MB degradation under visible light irradiation. Similarly, WO 2.72 /UiO-66(Zr) 198 and Co,Ni-MOF/BiFeO 3 213 composites were also prepared and displayed characteristic properties of Type I heterojunctions.…”

Judicious Selection of Precursors with Suitable Chemical Valence State for Controlled Growth of Transition Metal Chalcogenides

“…The increasing proportion of low valence state with the decreasing composition of oxygen in the precursor is consistent with previous reports. [45][46] According to pervious related reports, [47][48][49] the conversion from WO x to WS 2 is a gradual reduction reaction of losing oxygen, which can be expressed as the following two equations:…”

“…The increasing proportion of low valence state with the decreasing composition of oxygen in the precursor is consistent with previous reports. [ 45–46 ] According to pervious related reports, [ 47–49 ] the conversion from WO x to WS 2 is a gradual reduction reaction of losing oxygen, which can be expressed as the following two equations: $$$$\begin{equation} {\rm 2W{O}_3 + xS \to 2W{O}_{3 - x} + xS{O}_2}\end{equation}$$$$ $$$$\begin{equation} {\rm 2W{O}_{3 - x} + \left( {7 - x} \right)S \to 2W{S}_2 + \left( {3 - x} \right)S{O}_2}\end{equation}$$$$…”

Realization of Visible Light Photocatalysis by Wide Band Gap Pure SnO2 and Study of In2O3 Sensitization Porous SnO2 Photolysis Catalyst

“…The purpose is to promote separation of photogenerated electron‐hole pairs. It is because the Z‐type heterostructure or II‐type heterostructure is formed by photogenic electron transfer between heterostructure materials, which two different band gap semiconductors are coupled when light irradiated. Thus, the existence time of photogenic electrons and holes are extended.…”