Compact and uniform TiO2@g-C3N4 core-shell quantum heterojunction for photocatalytic degradation of tetracycline antibiotics
Compact and uniform TiO2@g-C3N4 core-shell quantum heterojunction for photocatalytic degradation of tetracycline antibiotics
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致密均匀的TiO2@g-C3N4核壳量子异质结用于光催化降解四环素抗生素
DOI：
10.1016/j.apcatb.2017.05.037
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发表时间：
2017-11-15
影响因子：
22.1
通讯作者：
Lu, Chunhua
中科院分区：
文献类型：
--
作者：
Wang, Wei;Fang, Jiaojiao;Lu, Chunhua
优化半导体光催化剂的异质结结构对于充分发挥其降解有机物的能力具有重要意义。在这里，我们展示了一个可行的策略，聚合量子厚的石墨碳氮化物（g-C3 N4）的表面上的纳米二氧化钛（TiO 2）的表面暴露的{001}方面，形成TiO 2 @ g-C3 N4（TCN）的核-壳量子异质结，以提高光催化四环素降解活性。100 mg的TCN光催化剂显示出最高的四环素降解速率为2.2 mg/min，这比TiO 2/g-C3 N4随机混合物（TCN（mix））高36%，比TiO 2高2倍，比本体g-C3 N4高2.3倍。结果还表明，H（+）和中心点O-2（-）是有效的光催化反应的主要氧化剂物种。提高TCN光催化活性的决定性因素是其独特的结构优势：量子厚的g-C3 N4壳层、致密均匀的接触界面、丰富的反应位点、表面吸附更多的羟基（OH）基团。TCN电极的光电流响应显著增强，荧光发射光谱显著降低，表明TiO 2和g-C3 N4之间存在有效的电子转移。本工作为通过表面异质结工程化合成高效、环境稳定的光催化剂提供了新的思路。(C)2017爱思唯尔B. V.保留所有权利。
Optimizing the heterojunction structure of semiconductor photocatalysts is significant for taking full advantage of their abilities for organic molecules degradation. Here, we demonstrate a feasible strategy of polymerizing the quantum-thick graphitic carbon nitride (g-C3N4) on to the surface of anatase titanium dioxide (TiO2) nanosheets with exposed {001} facets to form the TiO2@g-C3N4 (TCN) core-shell quantum heterojunction for improving photocatalytic tetracycline degradation activity. 100 mg of TCN photocatalyst shows the highest tetracycline degradation rate of 2.2 mg/min, which is 36% higher than that of the TiO2/g-C3N4 random mixture (TCN(mix)), 2 times higher than that of TiO2, and 2.3 times higher than that of bulk g-C3N4. Results also indicate that h(+) and center dot O-2(-) are the main oxidant species for the efficient photocatalytic reaction. The decisive factors in improving the photocatalytic activity of TCN is the unique structural advantages of quantum-thick g-C3N4 shell, compact and uniform contact interface, richly available reaction sites, more surface adsorbed hydroxyl (OH) groups. Efficient electron transfer between TiO2 and g-C3N4 is also demonstrated by the significant enhancement of photocurrent response of TCN electrodes and decrement of fluorescence emission spectra. This work demonstrates new sights for synthesizing high-efficient and environment-stable photocatalysts by engineering the surface heterojunction. (C) 2017 Elsevier B.V. All rights reserved.