Kinetics and mechanism of enhanced photocatalytic activity employing ZnS nanospheres/graphene-like C3N4
Kinetics and mechanism of enhanced photocatalytic activity employing ZnS nanospheres/graphene-like C3N4
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ZnS纳米球/类石墨烯C3N4增强光催化活性的动力学和机制
DOI：
10.1016/j.mcat.2017.05.023
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发表时间：
2017-09-01
影响因子：
4.6
通讯作者：
Li, Huaming
中科院分区：
文献类型：
--
作者：
Yan, Jia;Fan, Yamin;Li, Huaming
在这项工作中，通过简单的搅拌方法合成了一种新型光催化剂ZnS纳米球/类石墨烯g-C3N4（ZnS/GL-C3N4）纳米复合材料。通过 g-C3N4 热剥离合成的二维 (2D) 纳米材料 GL-C3N4 比块状 g-C3N4 具有更大的表面积和高效的光催化活性。 ZnS纳米球很好地锚定并覆盖在GL-C3N4纳米片的表面，ZnS和GL-C3N4之间的协同效应可以极大地提高GL-C3N4的光吸附能力以及提高光子产生的e(-)-h(+)对的分离效率，从而增强其在可见光照射下的光催化性能。本研究选择甲基橙（MO，一种纯C3N4难以降解的有机染料）和四环素（TC，一种代表性的广谱无色抗生素）作为污染物的降解目标。 ZnS/GL-C3N4 (50%) 的最佳光催化 MO 降解率分别比纯 ZnS 和 GL-C3N4 高出近 3.48 和 12.4 倍。 ZnS/GL-C3N4 (50%) 存在下，91% TC 被光降解，并且高于 GL-C3N4。此外，详细提出了可见光下MO降解的动力学和可能的光催化机制。除了协同效应外，捕获实验和ESR光谱表明，不仅O-2（中心点-）和空穴，而且（OH）-O-中心点都是活性物质，在该体系中发挥着重要作用，能够有效降解。我们的研究成果为开发高效光催化剂开辟了一条简单的途径。 (C) 2017 年由 Elsevier B.V. 出版
In this work, a novel photocatalyst ZnS nanospheres/graphene-like g-C3N4 (ZnS/GL-C3N4) nanocomposite was synthesized by a simple agitation method. Two-dimensional (2D) nanomaterial GL-C3N4, synthesized by thermal exfoliation from g-C3N4, showed large surface area and manifested efficient photocatalytic activity than bulk g-C3N4. ZnS nanospheres were well anchored and covered on the surface of GL-C3N4 nanosheets and a synergetic effect between the ZnS and GL-C3N4 could highly contributed to improvement of the light adsorption capability of GL-C3N4 as well as increasement of the separation efficiency of photon-generated e(-)-h(+) pairs, therefore, enhancing its photocatalytic performance under the illumination of visible light. Methyl orange (MO, a kind of organic dyes which is hard to be degraded by pure C3N4) and tetracycline (TC, a representative broad-spectrum colorless antibiotic agent) were chosen as the targets of pollutants for degradation in this study. The optimum photocatalytic MO degradation of ZnS/GL-C3N4 (50%) was almost 3.48 and 12.4 times higher than that of pure ZnS and GL-C3N4, respectively. 91% TC was photodegraded in the presence of ZnS/GL-C3N4 (50%) and higher than that of GL-C3N4. Furthermore, kinetics and possible photocatalytic mechanism of MO degradation under visible light was proposed in detail. Except for the synergetic effect, the trapping experiments and ESR spectra demonstrated that not only O-2(center dot-) and holes, but also (OH)-O-center dot were active species playing an importing role in this system for effective degradation. Our research results open an easy pathway for developing highly efficiency photocatalyst. (C) 2017 Published by Elsevier B.V.