金属有机骨架和g-C3N4共掺杂改性TiO2光催化性能

Photocatalytic performance of TiO2 Co-doped with metal organic framework and graphene like materials

摘要:

为了提高TiO₂光催化降解能力，采用溶胶-煅烧法使g-C₃N₄、ZIF-67与TiO₂进行共掺杂，制备了TiO₂-g-C₃N₄-ZIF-67催化剂。基于XRD、XPS、SEM、UV-vis DRS表征，考察了g-C₃N₄、ZIF-67对TiO₂形貌、结构的影响；通过甲基橙的降解率来评价TiO₂及其复合材料的光催化活性。结果表明，g-C₃N₄掺杂TiO₂较未掺杂样品带隙可由3.04 eV降低至2.45 eV，继续掺杂ZIF-67，掺杂后带隙进一步降低至1.91 eV，其中钴质量含量为21.50%对应的TiO₂-g-C₃N₄-ZIF-67-2活性最高，能够在40 min降解79.92%的甲基橙，在90 min降解89.50%的甲基橙。共掺杂样品具有良好的循环稳定性，TiO₂-g-C₃N₄-ZIF-67-2催化剂在三次循环后具有58.86%降解率。

Abstract:

In order to improve the photocatalytic degradation ability of TiO₂, TiO₂-g-C₃N₄-ZIF-67 catalysts were prepared by Co-doping g-C₃N₄, ZIF-67 with TiO₂ by sol-calcination method. The effects of g-C₃N₄, ZIF-67 on the morphology and structure of TiO₂ were investigated based on XRD, XPS, SEM, and UV-vis DRS characterization; and the photocatalytic activity of TiO₂and its composites was evaluated by the degradation rate of methyl orange. The results showed that the band gap of g-C₃N₄ doped TiO₂ could be reduced from 3.04 eV to 2.45 eV compared with that of undoped samples, and continued to be doped with ZIF-67, and the band gap was further reduced to 1.91 eV after doping, among which TiO₂-g-C₃N₄-ZIF-67-2 corresponding to a cobalt mass content of 21.50% had the highest activity and was able to degrade 79.92% of methyl orange in 40 min and 90 min. of methyl orange at 40 min and 89.50% of methyl orange at 90 min. The Co-doped samples had good cycling stability, and the TiO₂-g-C₃N₄-ZIF-67-2 catalyst had a degradation rate of 58.86% after three cycles.