Comprehensive investigation of the reciprocity of structure and enhanced photocatalytic performance in finned-tube structured TiO2/BiOBr heterojunctions
Comprehensive investigation of the reciprocity of structure and enhanced photocatalytic performance in finned-tube structured TiO2/BiOBr heterojunctions
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DOI：
10.1039/c5ra20510g
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发表时间：
2015-11
期刊：
影响因子：
3.9
通讯作者：
Chao Xue;Xin Xu;Guidong Yang;Shujiang Ding
中科院分区：
文献类型：
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作者：
Chao Xue;Xin Xu;Guidong Yang;Shujiang Ding
采用简单高效的溶剂热法合成了翅片管结构的二氧化钛@BiOBr型异质结。场发射扫描电子显微镜和透射电子显微镜分析表明，可调谐的片状结构的BiOBR纳米板从一维纳米管的表面萌发出来，形成了紧密的界面连接。由此提出了所制备的二氧化钛@BiOBr型异质结的形成机理。由于具有较强的可见光吸收、有效的电荷分离和光生电子-空穴对的低复合以及较大的比表面积，与已报道的同类催化剂相比，所制备的异质结具有最好的可见光催化活性、结构稳定性和持续循环性能。对RhB的光解循环7次后，其降解率仍保持在95.5%。基于光电流测量、光致发光分析和自由基捕获实验，提出了光催化活性增强的可能机理。结果表明，紧密的界面结促进了光生载流子的分离，同时，·O2−和h+都是可见光照射下RhB快速降解的主要反应物种.
Finned-tube structured TiO2@BiOBr heterojunctions were synthesized via a facile and efficient solvothermal process. Field-emission scanning electron microscopy and transmission electron microscopy analyses demonstrated that the tunable uniform lamellar structured BiOBr nanoplates burgeoned from the surface of one-dimensional TiO2 nanotubes and constructed intimate interfacial junctions. The formation mechanism of the as-prepared TiO2@BiOBr heterojunctions was thus proposed. Owing to the combined effects of the intense visible light absorption, the efficient charge separation and lower recombination of photo-generated electron–hole pairs as well as larger specific surface area, the as-fabricated heterojunctions exhibited the best visible-light photocatalytic activity, structural stability and sustained cycling performance compared with the reported congeneric catalysts. Their degradation rate remained at 95.5% after seven cycles for the photodecomposition of RhB. A possible mechanism of the photocatalytic activity enhancement was also proposed based on the photocurrent measurements, the photoluminescence analysis and the radical trapping experiments. It revealed that the intimate interfacial junction could promote the separation of photo-generated charge carriers, simultaneously, both ·O2− and h+ acted as the main reactive species in the rapid degradation of RhB under visible-light irradiation.