Constructing of ultrathin Bi2WO6/BiOCl nanosheets with oxygen vacancies for photocatalytic oxidation of cyclohexane with air in solvent-free
Constructing of ultrathin Bi2WO6/BiOCl nanosheets with oxygen vacancies for photocatalytic oxidation of cyclohexane with air in solvent-free
复制标题
构建带氧空位的超薄 Bi2WO6/BiOCl 纳米片用于无溶剂空气光催化氧化环己烷
DOI：
10.1016/j.apsusc.2022.152606
复制
发表时间：
2022-02-01
影响因子：
6.7
通讯作者：
Liu, Zhao-Tie
中科院分区：
文献类型：
--
作者：
Wang, Junlei;Wang, Kuan;Liu, Zhao-Tie
无溶剂光催化空气氧化环己烷是生产环己醇和环己酮(KA油)的一种高效、绿色的方法。在本工作中，通过一步溶剂热法通过改变氯化钾(KCl)的含量制备了超薄的Bi2WO6/BiOCl异质结纳米片。在光催化过程中，原位生成了Bi2WO6/BiOCl纳米片中的氧空位(OV)。在OV-Bi2WO6/BiOCl催化剂上，以空气为氧化剂，在无溶剂条件下实现了CHA的高效、选择性光氧化合成KA油。通过各种表征手段系统地分析了光催化剂的组成、结构、形貌以及织构、光学和电化学性质。与OV-Bi2WO6/BiOCl光催化反应相比，KA油的光催化活性显著提高，分别是纯BiOCl光催化剂和Bi2WO6催化剂的1.8和9.8倍。同时，KA油的选择性高达92.5%，循环5次，没有光催化活性损失。通过捕获实验和电子顺磁共振(EPR)测试，证明光生空穴(h(+))和中心点OH自由基是主要的反应物种。这种优异的光催化性能可以归因于增强的光吸收、丰富的氧空位、活性小面的高曝光率和有效的电子-空穴分离。因此，本工作为构建高效、选择性地光催化氧化CHA的铋基光催化剂提供了一种有前景的策略。
Photocatalytic oxidation of cyclohexane (CHA) with air in solvent-free is an efficient and green approach for the production of cyclohexanol and cyclohexanone (KA oil). In the present work, ultrathin Bi2WO6/BiOCl heterojunction nanosheets are prepared by varying the amounts of potassium chloride (KCl) via a one-step solvothermal method. The oxygen vacancies (OV) in Bi2WO6/BiOCl nanosheets can be produced in situ during the photocatalysis. An efficient and selective photo-oxidation of CHA to KA oil with air as an oxidant in solvent-free was achieved over OV-Bi2WO6/BiOCl catalyst. The composition, structure, morphology, as well as textural, optical, and electrochemical properties of the photocatalysts are systematically analyzed by various characterization techniques. The photocatalytic activity (KA oil, 484.4 mu mol) for the titled reaction was significantly improved over OV-Bi2WO6/BiOCl with 1.8 and 9.8 times compared with that by pure BiOCl and Bi2WO6 catalysts, respectively. Meanwhile, up to 92.5% selectivity of KA oil and 5 cycles without photocatalytic activity loss were achieved. The photogenerated holes (h(+)) and center dot OH radicals are verified to be predominant reactive species by trapping experiments and electron paramagnetic resonance (EPR) tests. The excellent photocatalytic performance can be attributed to the enhanced photo-absorption, abundant oxygen vacancies, high exposure of active facets, and efficient electron-hole separation. Thereby, the present work offers a prospective strategy for constructing Bi-based photocatalyst with highly efficient and selective photocatalytic oxidation of CHA.