School of Science, China University of Geosciences

利用太阳能将CO2转化为CH4,能够同时缓解能源危机及温室效应。本研究以对苯二甲酸(H2BDC)和铜盐或镍盐为原料,利用超声法合成了两种二维金属有机骨架材料(MOF)Cu-BDC和Ni-BDC,通过X射线衍射、X射线光电子能谱、电镜等对其结构组成和形貌进行了表征,并进行了紫外可见漫反射光谱、阻抗、光电流响应等光电性能测试。在模拟太阳光下,Ni-BDC光催化CO2还原CH4产率高达95.22μmol·g-1·h-1,选择性为75%,并表现出良好的稳定性,这归因于n型半导体Ni-BDC具有更负的导带位置,能够产生更高的光生电荷效率。结果表明:金属活性中心的选择能够有效调控MOF的光催化性能。

Converting CO into CH by solar energy can relieve energy crisis and greenhouse effect. In this study, two-dimensional (2D) metal organic frameworks (MOF), Cu-BDC (BDC=1,4-benzenedicarboxylate) and Ni-BDC were successfully prepared by the reaction of terephthalic acid (H BDC) and cuprum (Cu) or nickel (Ni) salt through ultrasonic treatment. The structure and the morphology were well represented by X-ray diffraction, X-ray photoelectron spectroscopy and electron microscopes. The photoelectric properties were investigated by UV-visible diffuse reflectance spectrum, impedance, and photocurrent response. Under simulated sunlight, Ni-BDC could be used as photocatalyst for CO to CH conversion, showing excellent efficiency with a CH production rate as high as 95.22 μmol·g ·h , a selectivity of 75%, and perfect stability, which was superior to Cu-BDC. This was attributed to the more negative conduction band position for n-type semiconductor Ni-BDC, which was beneficial to improve the efficiency of photo-generated electrons. The results show that the selection of metal active centers can effectively regulate the photocatalytic performance of MOF.

国家自然科学基金项目(22001240);中国地质大学(北京)2024年度研究生教育教学改革专项;中国地质大学(北京)2023年度本科教育质量提升建设项目