Surfactant-assisted synthesis of direct Z-scheme AgBr/β-Ag2WO4 heterostructures with enhanced visible-light-driven photocatalytic activities
Surfactant-assisted synthesis of direct Z-scheme AgBr/β-Ag2WO4 heterostructures with enhanced visible-light-driven photocatalytic activities
复制标题
表面活性剂辅助合成直接 Z 型 AgBr/beta-Ag2WO4 异质结构，具有增强的可见光驱动光催化活性
DOI：
10.1016/j.mssp.2019.104688
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发表时间：
2019
影响因子：
4.1
通讯作者：
Xiaoheng Liu
中科院分区：
文献类型：
--
作者：
Hongfei Yin;Xiaoheng Liu
与传统的两步离子交换法制备AgBr/β-Ag 2 WO 4异质结构相比，本文采用简单的表面活性剂辅助一步沉淀法制备了一系列AgBr/β-Ag 2 WO 4直接Z型异质结构。采用X射线衍射（XRD）、扫描电镜（SEM）、透射电镜（TEM）、紫外-可见漫反射光谱（UV-vis DRS）、X射线光电子能谱（XPS）、光致发光谱（PL）、光电化学测试等手段对AgBr/β-Ag 2 WO 4异质结构的物相结构、形貌、化学组成及光催化机理进行了系统表征。以罗丹明（RhB）的可见光催化降解为探针，考察了其光催化活性。结果表明，AgBr/β-Ag 2 WO 4 -30%的光催化活性最高，分别是纯AgBr和纯β-Ag 2 WO 4的1.7倍和135.9倍。通过对AgBr/β-Ag 2 WO 4异质结的系统表征和测量，详细描述了异质结中载流子的分离和转移途径，以及直接Z模式机理。AgBr/β-Ag 2 WO 4异质结构光催化性能的提高主要归因于两种半导体之间形成了较大的比表面积和Z型体系，导致了光生电子和空穴的空间分离。这一工作为理解AgBr/β-Ag 2 WO 4异质结的形成机理提供了新的视角，即直接Z型异质结而不是II型异质结。
Compared with the conventional two-step ion exchange method used for the fabrication of AgBr/β-Ag2WO4heterostructures, herein, a series of AgBr/β-Ag2WO4direct Z-scheme heterostructures were efficiently fabricated via a simple surfactant-assisted one-step precipitation strategy. The phase structure, morphology, chemical composition as well as photocatalytic mechanism of the as-obtained AgBr/β-Ag2WO4heterostructures were systematically characterized by using X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Ultraviolet–Visible diffuse reflectance spectra (UV–vis DRS), X-ray photoelectron spectroscopy (XPS), Photoluminescence spectrum (PL), photoelectrochemical tests. Photocatalytic degradation of Rhodamine (RhB) under visible light was carried out as a probe to assess its photocatalytic activity. The result indicates that AgBr/β-Ag2WO4-30% exhibits the highest photocatalytic activity, which is approximately 1.7 and 135.9 times as high as that of pure AgBr and pure β-Ag2WO4, respectively. The pathway of charge carriers separation and transfer in the AgBr/β-Ag2WO4heterostructures and the direct Z-scheme mechanism were depicted in details based on the systematic characterizations and measurements. The enhancement of the photocatalytic performances of the as-prepared AgBr/β-Ag2WO4heterostructures are mainly attributed to the larger specific surface area and Z-scheme system formed between these two semiconductors, leading to the spatial separation of the photoinduced electron and hole. This work may provide a new sight to understand the mechanism of AgBr/β-Ag2WO4heterostructures, which is direct Z-scheme heterojunctions rather than type-II heterojunctions.