Facile fabrication of a direct Z-scheme Ag2CrO4/g-C3N4 photocatalyst with enhanced visible light photocatalytic activity
Facile fabrication of a direct Z-scheme Ag2CrO4/g-C3N4 photocatalyst with enhanced visible light photocatalytic activity
复制标题
轻松制备具有增强可见光催化活性的直接 Z 型 Ag2CrO4/g-C3N4 光催化剂
DOI：
10.1016/j.molcata.2016.05.024
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发表时间：
2016-09-01
影响因子：
--
通讯作者：
Chen, Fei
中科院分区：
文献类型：
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作者：
Deng, Yaocheng;Tang, Lin;Chen, Fei
类石墨碳氮化物（g-C3 N4）和银系化合物由于其优异的光学特性和光催化性能而受到人们的广泛关注。本文采用沉淀法将Ag 2CrO 4纳米粒子结合生长在g-C3 N4纳米片（g-C3 N4-N）表面，制备了Z型铬酸银-g-C3 N4纳米片光催化剂。采用X射线衍射（XRD）、场发射扫描电子显微镜（FE-SEM）、透射电子显微镜（TEM）、高分辨透射电子显微镜（HR-TEM）、X射线光电子能谱（XPS）、紫外-可见漫反射光谱（UV-vis DRS）和光致发光光谱（PL）等手段对催化剂的形貌、结构、比表面积和光学性能进行了表征。以橙子（MO）和罗丹明B（RhB）为目标染料，在可见光（λ> 400 nm）照射下，考察了Ag 2CrO 4/g-C3 N4-N的光催化性能。实验结果表明，Ag 2CrO 4/g-C3 N4-N复合材料在降解水溶液中的染料污染物时，表现出较好的光催化活性和稳定性。当Ag 2CrO 4与g-C3 N4-N的质量比为50%（CNA-50）时，复合材料的光催化活性最高，分别是Ag 2CrO 4和g-C3 N4-N的5.9倍和10.8倍。Ag 2CrO 4/g-C3 N4-N Z型异质结的形成有助于提高光降解效率，不仅可以促进光生电子-空穴对的分离和传输效率，而且具有较强的氧化还原能力。同时，光生电子从Ag 2CrO 4到g-C3 N4-N的良好传输效率极大地抑制了Ag 2CrO 4纳米粒子的光腐蚀。本工作为g-C3 N4-N基复合材料的机理提供了新的认识，并为Z型光催化剂的设计和制备提供了新的见解。(C)2016爱思唯尔B. V.保留所有权利。
Graphite-like carbon nitride (g-C3N4) and silver-based compounds have attracted considerable attentions due to their excellent optical characteristic and photocatalytic performance. In this work, Z-scheme silver chromate-g-C3N4 nanosheets photocatalysts were prepared by binding growth of Ag2CrO4 nanoparticles on the surface of g-C3N4 nanosheets (g-C3N4-N) via a facile precipitation method. The morphologies, structure, specific surface area and optical property of the prepared photocatalysts were characterized by X-ray diffraction (XRD), field emission-scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), high resolution-transmission electron microscopy (HR-TEM), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectra (UV-vis DRS) and photoluminescence (PL) spectra. The photocatalytic performances of the prepared Ag2CrO4/g-C3N4-N were evaluated by photodegradation of methyl orange (MO) and rhodamine B (RhB) under visible light irradiation (lambda >400nm). The experiment results indicated that Ag2CrO4/g-C3N4-N composites presented enhanced photocatalytic activity and stability in the degradation of the dye contaminants in aqueous solution. The optimal composites with the mass ratio of Ag2CrO4 to g-C3N4-N as 50% (CNA-50) showed the highest photocatalytic activity for MO degradation, which is 5.9 and 10.8 times than those of pure Ag2CrO4 and pure g-C3N4-N, respectively. The formation of Ag2CrO4/g-C3N4-N Z-scheme heterojunction contributed to the improved photodegradation efficiency, which can not only promote the separation and transportation efficiencies of the photogenerated electron-hole pairs, but also present strong redox ability. And meanwhile the excellent transportation efficiency of the photogenerated electrons from Ag2CrO4 to g-C3N4-N greatly hindered the photocorrosion of Ag2CrO4 nanoparticles. This work provides a new understanding into the mechanism of the g-C3N4-N based composite and gives a new insight into the design and fabrication of Z-scheme photocatalysts. (C) 2016 Elsevier B.V. All rights reserved.