Wang Yuting, Hao Xin, Wang Zegao, Dong Mingdong, Cui Lifeng
School of Environment and Civil Engineering, Dongguan University of Technology, Guangdong 523808, People's Republic of China.
Department of Engineering, Materials and Polymer Engineering, Nanofiber Technology and Cellular Engineering, Menglin Chen group, Aarhus University, DK-8000 Aarhus C, Denmark.
R Soc Open Sci. 2020 Apr 22;7(4):191050. doi: 10.1098/rsos.191050. eCollection 2020 Apr.
In this study, a high-efficiency photocatalyst was synthesized by Mn-doped ZnO nanofibres (NFs) fabricated by facile electrospinning and a following annealing process, in which Mn successes incorporate to ZnO NFs lattice without changing any morphology and crystalline structure of ZnO. The photodegradation properties of ZnO loading with different concentrations of Mn (5, 10, 15 and 50 at%) were investigated. The 50% MnO-ZnO composite owns excellent active photocatalytic performance (quantum efficiency up to 7.57%) compared to pure ZnO (0.16%) under visible light and can be considered as an efficient visible light photocatalyst material. We systematically analysed its catalytic mechanism and found that the enhancement belongs to the Mn doping effect and the phase junction between MnO and ZnO. The dominant mechanism of Mn doping leads to the presence of impurity levels in the band gap of ZnO, narrowing the optical band gap of ZnO. In addition, doped Mn ions can be used as electron traps that inhibit the recombination process and promote electron-hole pair separation. In summary, this paper provides a convenient method for fabricating highly efficient visible light photocatalysts using controlled annealing.
在本研究中，通过简便的静电纺丝和后续退火工艺制备的锰掺杂氧化锌纳米纤维（NFs）合成了一种高效光催化剂，其中锰成功掺入氧化锌NFs晶格中，而不改变氧化锌的任何形态和晶体结构。研究了负载不同浓度锰（5、10、15和50原子%）的氧化锌的光降解性能。与纯氧化锌（0.16%）相比，50%的MnO-ZnO复合材料在可见光下具有优异的活性光催化性能（量子效率高达7.57%），可被视为一种高效的可见光光催化剂材料。我们系统地分析了其催化机理，发现这种增强属于锰掺杂效应以及MnO与ZnO之间的相结。锰掺杂的主要机制导致氧化锌带隙中存在杂质能级，缩小了氧化锌的光学带隙。此外，掺杂的锰离子可作为电子陷阱，抑制复合过程并促进电子-空穴对的分离。总之，本文提供了一种通过控制退火制备高效可见光光催化剂的简便方法。
