蜂窝状C3N4/CoSe2/GA复合光催化剂的制备及CO2还原性能

以六水金氯化钴、 硒粉和尿素为前驱体, 通过水热法合成C₃N₄/CoSe₂纳米粒子， 再将其锚定在石墨烯气凝胶（Graphene aerogel， GA）表面， 制备蜂窝状C₃N₄/CoSe₂/GA光催化剂. 采用X射线衍射(XRD)、 X射线光电子能谱(XPS)、 扫描电子显微镜(SEM)、 透射电子显微镜(TEM)和紫外-可见漫反射光谱(UV-Vis DRS)等手段对材料的结构、 形貌和光学性能进行表征. 同时以氙灯作为模拟可见光光源, 通过CO₂光催化还原为CO考察所制备纳米材料的光催化活性. 结果表明, 在C₃N₄纳米片表面引入了CoSe₂和GA并制备出蜂窝状结构 C₃N₄/CoSe₂/GA催化剂, 通过GA, CoSe₂与C₃N₄耦合可以显著提高光吸收密度以及扩展光响应范围, 呈现了更低的荧光强度和最大的电子转移速率. 在同种光催化下, C₃N₄/CoSe₂/GA对CO₂还原催化效率最大, CO产量达到5.75 μmol·g^-1·h^-1, 并且重复使用性能良好.

Preparation of Cellular C3N4/CoSe2/GA Composite Photocatalyst and Its CO2 Reduction Activity

C₃N₄/CoSe₂ nanoparticles were synthesized by hydrothermal method using cobalt chloride hexahydrate， selenium powder and urea as precursors， and then were anchor on the surface of graphene aerogel（GA） to prepare C₃N₄/CoSe₂/GA photocatalyst. The structure， surface morphology and optical properties of the materials were characterized by X-ray diffraction（XRD）， X-ray photoelectron spectroscopy（XPS）， scanning electron microscopy（SEM）， transmission electron microscopy（TEM） and UV-Vis diffuse-relective spectroscopy（UV-Vis DRS）. At the same time， the photocatalytic activity of the prepared nanomaterials was investigated by reduction of CO₂ to CO with using the xenon lamp as visible light source. The results showed that the cellular C₃N₄/CoSe₂/GA catalyst was successfully prepared by introducing CoSe₂ and GA on the surface of C₃N₄ nanometer sheet， and the coupling of GA and CoSe₂ with C₃N₄ could significantly improve the optical absorption density and expand the optical response range， showing lower fluorescence intensity and maximum electron transfer rate. Under the same photocatalysis condition， C₃N₄/CoSe₂/GA displayed the highest catalytic efficiency for CO₂ reduction， the CO yield reached 5.75 μmol·g^-1·h^-1， and the photocatalytic performance was good in repeating process.