改性碳化钛阴极的光催化系统还原CO_(2)研究

CO_(2) reduction in photocatalytic system with modified Ti_(3)C_(2) cathode

采用氢氟酸(HF)侵蚀钛碳化铝(Ti_(3)AlC_(2))的方法制备了碳化钛(Ti_(3)C_(2))催化剂,对其进行表面基团碱化后,作为光催化还原二氧化碳(CO_(2))的阴极催化剂。采用X射线衍射(XRD)和扫描电子显微镜(SEM)对其表面进行表征。在以二氧化钛纳米管(TiO_(2)-NTs)为光阳极的光催化燃料电池中进行CO_(2)还原性测试。测试发现,经表面碱化的Ti_(3)C_(2)催化剂的CO_(2)还原性能明显提高,但由于大量H^(+)的存在导致循环稳定性较差。通过引入氟基疏水层来增强操作稳定性,该疏水层使得催化剂与水溶液的接触减少,抑制H^(+)对表面碱性基团的破坏,使系统能够高效稳定运行。

Titanium carbide(Ti_(3)C_(2))catalyst was prepared by hydrofluoric acid(HF)etching titanium aluminum carbide(Ti_(3)AlC_(2)),which was used as cathode catalyst for photocatalytic reduction of carbon dioxide(CO_(2))after alkalization of surface groups.The surface properties of cathode catalyst were investigated by X-ray diffraction(XRD)and scanning electron microscope(SEM).CO_(2)reducibility was tested in photocatalytic fuel cells with titanium dioxide nanotubes(TiO_(2)-NTs)as photoanode.It was found that the reduction performance of Ti_(3)C_(2)catalyst after surface alkalization was significantly improved,but the cycle stability was poor due to the presence of a large amount of hydrogen ions(H^(+)).Operational stability was enhanced via the introduction of a fluorine-based hydrophobic layer,which reduced the contact between the catalyst and the aqueous solution,and inhibited the damage of H^(+) to the surface alkaline groups,and enabled the system to run smoothly.