Photocatalytic removal of NO by light-driven Mn3O4/BiOCl heterojunction photocatalyst: Optimization and mechanism
Photocatalytic removal of NO by light-driven Mn3O4/BiOCl heterojunction photocatalyst: Optimization and mechanism
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DOI：
10.1016/j.cej.2020.128014
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发表时间：
2021-03
影响因子：
15.1
通讯作者：
Ting Shen;Xueke Shi;Jiaxiu Guo;Jing Li;S. Yuan
中科院分区：
文献类型：
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作者：
Ting Shen;Xueke Shi;Jiaxiu Guo;Jing Li;S. Yuan
采用简单的一步水热合成法合成了Mn3O4/BiOCl异质结光催化剂，并对其进行了表征。研究了其光学性质和电子特性。利用制备的Mn3O4/BiOCl在模拟太阳光照下去除NO，并采用长周期、多周期、捕集实验、ESR和in - siturifts等方法考察了Mn3O4/BiOCl、主要活性物质和反应产物的稳定性。结果表明，mn3o4纳米颗粒成功沉积在微花BiOCl上，形成了mn3o4与BiOCl之间的异质结界面。与纯BiOCl相比，Mn3O4/BiOCl的表面氧空位增加，Mn3O4作为电子受体促进电子从BiOCl向Mn3O4转移。光学性能的增强归因于Mn3O4/BiOCl良好的能带结构，有利于光生载流子分离。Mn3O4/BiOCl在10 min内达到75%左右的NO去除率，在光照射下对no2表现出较好的抑制能力，但由于产物的积累，光催化活性逐渐降低。与Mn3O4/BiOCl相比，在模拟气体中加入5或10 vol%的H2O时，NO的去除效率有所提高，但对no2的抑制作用略有减弱。Mn3O4/BiOCl的异质结、光学性质和形貌稳定，但反应后氧空位增加。由于Mn3O4/BiOCl的z型异质结，在光照射下产生的自由基dotO2−和自由基dotOH自由基对NO氧化为NO3−具有活性。
A Mn3O4/BiOCl heterojunction photocatalyst was synthesized via a facile one-step hydrothermal synthesis method and characterized. The optical properties and electron characteristic are also investigated. The prepared Mn3O4/BiOCl was used to remove NO under the simulated solar light irradiation, and the long-period and multiple-cycles, capture experiments, ESR andin situDRIFTS were used to investigate the stability of Mn3O4/BiOCl, the main active species and reaction products. The results showed that Mn3O4nanoparticles are successfully deposited on micro-flower BiOCl to form a heterojunction interface between Mn3O4and BiOCl. Compared with pure BiOCl, the surface oxygen vacancies of Mn3O4/BiOCl increases, and Mn3O4acts as an electron acceptor to promote the transfer of electrons from BiOCl to Mn3O4. The enhancement of the optical properties is ascribed to a good energy band structure of Mn3O4/BiOCl, facilitating photogenerated carrier separation. Mn3O4/BiOCl achieves about 75% of NO removal efficiency within 10 min and exhibits superior inhibition ability for NO2under light irradiation, but the photocatalytic activities gradually decrease due to the accumulation of products. When 5 or 10 vol% H2O is added into the simulated gas, the NO removal efficiency has been increased over Mn3O4/BiOCl, but the inhibition effect of NO2is slightly weakened. The heterojunctions, optical properties and morphologies of Mn3O4/BiOCl are stable but the oxygen vacancies increase after reaction. The producedradical dotO2−andradical dotOH radicals are active for the oxidation of NO to NO3−under light irradiation, which is due to the Z-scheme heterojunctions of Mn3O4/BiOCl.