Yousefi Ramin, Beheshtian Javad, Seyed-Talebi Seyedeh Mozhgan, Azimi H R, Jamali-Sheini Farid
Department of Physics, Masjed-Soleiman Branch, Islamic Azad University (I.A.U), Masjed-Soleiman, Iran.
Department of Chemistry, Shahid Rajaee Teacher Training University, Lavizan, Tehran, Iran.
Chem Asian J. 2018 Jan 18;13(2):194-203. doi: 10.1002/asia.201701423. Epub 2018 Jan 5.
A systematic experimental and theoretical study of the origin of the enhanced photocatalytic performance of Mg-doped ZnO nanoparticles (NPs) and Mg-doped ZnO/reduced graphene oxide (rGO) nanocomposites has been performed. In addition to Mg, Cd was chosen as a doping material for the bandgap engineering of ZnO NPs, and its effects were compared with that of Mg in the photocatalytic performance of ZnO nanostructures. The experimental results revealed that Mg, as a doping material, recognizably ameliorates the photocatalytic performance of ZnO NPs and ZnO/graphene nanocomposites. Transmission electron microscopy (TEM) images showed that the Mg-doped and Cd-doped ZnO NPs had the same size. The optical properties of the samples indicated that Cd narrowed the bandgap, whereas Mg widened the bandgap of the ZnO NPs and the oxygen vacancy concentration was similar for both samples. Based on the experimental results, the narrowing of the bandgap, the particle size, and the oxygen vacancy did not enhance the photocatalytic performance. However, Brunauer-Emmett-Teller (BET) and Barret-Joyner-Halenda (BJH) models showed that Mg caused increased textural properties of the samples, whereas rGO played an opposite role. A theoretical study, conducted by using DFT methods, showed that the improvement in the photocatalytic performance of Mg-doped ZnO NPs was due to a higher electron transfer from the Mg-doped ZnO NPs to the dye molecules compared with pristine ZnO and Cd-doped ZnO NPs. Moreover, according to the experimental results, along with Mg, graphene also played an important role in the photocatalytic performance of ZnO.
已对镁掺杂氧化锌纳米颗粒（NPs）和镁掺杂氧化锌/还原氧化石墨烯（rGO）纳米复合材料光催化性能增强的起源进行了系统的实验和理论研究。除了镁之外，还选择镉作为氧化锌纳米颗粒带隙工程的掺杂材料，并将其在氧化锌纳米结构光催化性能方面的效果与镁的效果进行了比较。实验结果表明，作为掺杂材料的镁可显著改善氧化锌纳米颗粒和氧化锌/石墨烯纳米复合材料的光催化性能。透射电子显微镜（TEM）图像显示，镁掺杂和镉掺杂的氧化锌纳米颗粒尺寸相同。样品的光学性质表明，镉使带隙变窄，而镁使氧化锌纳米颗粒的带隙变宽，且两个样品的氧空位浓度相似。基于实验结果，带隙变窄、粒径和氧空位并未提高光催化性能。然而，布鲁诺尔-埃米特-泰勒（BET）和巴雷特-乔伊纳-哈伦达（BJH）模型表明，镁使样品的织构性质增加，而还原氧化石墨烯则起到相反的作用。使用密度泛函理论（DFT）方法进行的理论研究表明，镁掺杂氧化锌纳米颗粒光催化性能的提高是由于与原始氧化锌和镉掺杂氧化锌纳米颗粒相比，从镁掺杂氧化锌纳米颗粒到染料分子的电子转移更高。此外，根据实验结果，除了镁之外，石墨烯在氧化锌的光催化性能中也起到了重要作用。
