Hu Weineng, Jiang Mengmeng, Liang Ruowen, Huang Renkun, Xia Yuzhou, Liang Zhiyu, Yan Guiyang
State Key Laboratory of Photocatalysis on Energy and Environment, Fuzhou University, Fuzhou 350002, P. R. China.
Dalton Trans. 2021 Feb 21;50(7):2596-2605. doi: 10.1039/d0dt03922e. Epub 2021 Feb 1.
In this work, a novel step-scheme (S-scheme) BiMoO/CdS heterojunction (HJ) photocatalyst (PC) was successfully prepared by a two-step solvothermal method for the first time. One-dimensional CdS nanorods were prepared by a simple solvothermal method as a synthesis template. Then, a BiMoO precursor was added to obtain a series of BiMoO/CdS HJ composite catalytic materials with different morphologies. The photocatalytic performance of the catalyst was investigated by simulating fuel denitration as a probe reaction under visible light excitation (>420 nm). When compared with pure BiMoO and CdS, the 0.65-BiMoO/CdS composite shows the highest photocatalytic activity for pyridine degradation. Degradation of pyridine reached 81% after 240 min of visible light excitation. The degradation rate of 0.65-BiMoO/CdS reached 0.4471 h, which was 1.8 and 3.2 times higher than that of CdS (0.2493 h) and BiMoO (0.1427 h), respectively. Combined with a series of characterisation results, the improvement in pyridine degradation activity was mainly attributed to (1) the S-scheme HJ structure between BiMoO and CdS, which greatly promoted the separation of photogenerated electrons and holes while retaining its strong redox ability, (2) the large specific surface area, which provided abundant active sites and efficient adsorption performance and catalytic performance, and (3) the special morphology, which induced multiple reflections of light, thereby improving absorption and utilisation of light. Moreover, after four cycles of pyridine denitrification, the samples still exhibited high activity, indicating good stability and recyclability of the composite catalyst. These findings provide a basis for the development of composite PCs for efficient fuel denitration under visible light irradiation.
在本工作中，首次通过两步溶剂热法成功制备了一种新型的阶梯式（S型）BiMoO/CdS异质结（HJ）光催化剂（PC）。采用简单的溶剂热法制备一维CdS纳米棒作为合成模板。然后，加入BiMoO前驱体，得到一系列不同形貌的BiMoO/CdS HJ复合催化材料。以模拟燃料脱硝为探针反应，在可见光激发（>420 nm）下研究了催化剂的光催化性能。与纯BiMoO和CdS相比，0.65-BiMoO/CdS复合材料对吡啶降解表现出最高的光催化活性。可见光激发240 min后，吡啶降解率达到81%。0.65-BiMoO/CdS的降解速率达到0.4471 h，分别是CdS（0.2493 h）和BiMoO（0.1427 h）的1.8倍和3.2倍。结合一系列表征结果，吡啶降解活性的提高主要归因于：（1）BiMoO和CdS之间的S型HJ结构，极大地促进了光生电子和空穴的分离，同时保留了其较强的氧化还原能力；（2）大比表面积，提供了丰富的活性位点以及高效的吸附性能和催化性能；（3）特殊的形貌，诱导了光的多次反射，从而提高了光的吸收和利用。此外，经过四次吡啶脱硝循环后，样品仍表现出高活性，表明复合催化剂具有良好的稳定性和可循环性。这些发现为开发用于可见光照射下高效燃料脱硝的复合光催化剂提供了依据。
