类石墨相氮化碳的制备及光催化还原CO2 性能研究

Syntheses of the graphite phase carbonic nitrogen(g-C3N4) for photocatalytically reducing CO2

摘要:

分别以尿素、三聚氰胺为前驱体，采用缩聚法制备不同形貌及性能的类石墨相氮化碳(g-C3N4)半导体催化剂，探究不同前驱体对催化剂的形貌及光催化还原CO2活性的影响。采用X射线衍射（XRD）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）、紫外-可见光分光光度计（Uv-vis）、傅氏转换红外线光谱分析（FTIR）、比表面积测试（BET）、荧光光谱（PL）对所得g-C3N4进行各方面性能的探究，从而分析前驱体对所得产物性能的影响。实验结果表明，以尿素为前驱体制备出的g-C3N4在甲醇溶液中光催化还原CO2制备甲酸甲酯的产率 为512.8μmol/gcat•h ，以三聚氰胺为前驱体制备出的g-C3N4光催化产率为257.3 μmol/gcat•h。

Abstract:

Abstract: The graphite phase carbon nitride (g-C3N4) semiconductors with different morphologies and photocatalytic performance were prepared by polycondensation method, using urea and melamine as precursors respectively. The catalytic performance of the g-C3N4 was measured by the reduction of CO2 in methanol under light irradiation. X-ray diffraction (XRD)、Scanning electron microscope (SEM)、Transmission electron microscope (TEM)、UV-vis spectrophotometry (UV-vis)、Fourier transform infrared spectroscopy (FTIR)、Specific surface area measurements (BET) and Fluorescence spectrum (PL) were applied to analyze the influence of different precursors to the photocatalytic activity of g-C3N4. Results showed that g-C3N4 using urea as precursor had better photocatalytic activity for CO2 reduction and the formation rate of methyl formate (MF) in methanol reached up to 512.8μmol/gcat.h, nevertheless that of the g-C3N4 made from melamine was only 257.3 μmol/gcat.h.