Lv Jiaxin, Hu Qingsong, Cao Chengjin, Zhao Yaping
School of Ecological and Environmental Science, Shanghai Key Laboratory for Urban Ecological Processes and Eco-Restoration, East China Normal University, Shanghai 200241, China.
School of Ecological and Environmental Science, Shanghai Key Laboratory for Urban Ecological Processes and Eco-Restoration, East China Normal University, Shanghai 200241, China.
Chemosphere. 2018 Jan;191:427-437. doi: 10.1016/j.chemosphere.2017.09.149. Epub 2017 Oct 1.
To better know the photocatalytic performance of bismuth oxyhalides (BiOX, X = Cl, Br, I) regulated by incorporation of halides within nanostructures, BiOX nanosheets were synthesized through morphology controllable solvothermal method and characterized systematically. The organic structural property greatly influences the photocatalytic activity of BiOX: 1) as for neutral molecular phenol, BiOX shows photocatalytic activity in the order of BiOCl > BiOBr > BiOI under simulated sun light irradiation, and the photo-oxidation kinetics follow Eley-Rideal mechanism; and 2) for adsorbed anionic orange II (OII) and cationic methylene blue (MB), BiOX shows photocatalytic activity in the order of BiOCl > BiOBr > BiOI, and the photo-oxidation kinetics follow Langmuir-Hinshelwood mechanism. The crystal structure of the catalyst also greatly influences the photocatalytic activity of BiOX: 1) The relative photo-oxidation power of O radicals or HO radicals involved in this study were different which were quantitatively detected using typical radical trapping agent, separately; 2) The relative oxidation power of photogenerated holes (h) in this study were in the order of BiOCl > BiOBr > BiOI, which may be ascribed to lowering the valence band maximum edge of BiOX through incorporation of halides as the atomic number of halides decreased. This study provides novel explanation for fabricating BiOX heterojunctions with tunable photocatalytic reactivity via regulating the halides ratio.
为了更好地了解通过在纳米结构中引入卤化物来调控的卤氧化铋（BiOX，X = Cl、Br、I）的光催化性能，采用形貌可控的溶剂热法合成了BiOX纳米片并进行了系统表征。有机结构性质对BiOX的光催化活性有很大影响：1）对于中性分子苯酚，在模拟太阳光照射下，BiOX的光催化活性顺序为BiOCl > BiOBr > BiOI，且光氧化动力学遵循埃利-里德尔机制；2）对于吸附的阴离子橙II（OII）和阳离子亚甲基蓝（MB），BiOX的光催化活性顺序为BiOCl > BiOBr > BiOI，且光氧化动力学遵循朗缪尔-欣谢尔伍德机制。催化剂的晶体结构也对BiOX的光催化活性有很大影响：1）本研究中涉及的O自由基或HO自由基的相对光氧化能力不同，分别使用典型的自由基捕获剂进行了定量检测；2）本研究中光生空穴（h⁺）的相对氧化能力顺序为BiOCl > BiOBr > BiOI，这可能归因于随着卤化物原子序数的降低，通过引入卤化物降低了BiOX的价带最大边缘。本研究为通过调节卤化物比例制备具有可调光催化反应活性的BiOX异质结提供了新的解释。
