通过构建异质结的策略，利用光催化材料石墨相氮化碳（g-C₃N₄）和导电聚合物聚苯胺（PANI）耦合制备了g-C₃N₄/PANI复合材料。采用X射线衍射（XRD）、傅里叶红外光谱（FT-IR）、X射线光电子能谱（XPS）、扫描电镜（SEM）、紫外-可见漫反射光谱（UV-vis DRS）、稳态/瞬态光致发光光谱（PL和TRPL）、瞬态光电流谱（TPC）和电化学交流阻抗谱（EIS）等技术手段对复合材料的形貌、元素组成和光电化学等性质进行了表征和性能评价。结果表明，g-C₃N₄/PANI复合材料的结构是PANI均匀地覆盖在g-C₃N₄表面，并且g-C₃N₄和PANI之间存在异质结结构。经PANI包裹后，g-C₃N₄的比表面积从21.31 m²/g显著提升至66.13 m²/g，增大了约2.10倍，有效地提升了光催化性能。通过优化PANI添加量，g-C₃N₄/PANI（3%，质量分数，下同）复合材料表现出最佳的可见光光催化还原CO₂性能，CH₃OH的时空产率达到3.12 μmol/（g·h），是纯g-C₃N₄的4.27倍。异质结的构建拓宽了g-C₃N₄/PANI（3%）复合材料在可见光区光谱响应的范围，有效促进了光生载流子的分离，交流阻抗显著降低，电荷转移速率明显提升，从而使光催化还原CO₂性能得到显著提升。气相色谱分析表明，反应的主要产物为CH₃OH，同时伴有少量的CO生成，证实了g-C₃N₄/PANI（3%）复合材料作为催化剂具有较好的选择性。循环5次后，CH₃OH的时空产率仍高于2.97 μmol/（g·h），保持了95%以上的活性。最后，通过价带X射线光电子能谱（VB-XPS）表征和Mott-Schottky曲线分析得到了能带结构，g-C₃N₄/PANI复合材料可见光光催化还原CO₂机理遵循Type-Ⅱ机理。

The g-C₃N₄/PANI composite was prepared by coupling the photocatalytic material graphite carbon nitride（g-C₃N₄） and the conductive polymer polyaniline（PANI） by constructing a heterojunction strategy.The morphology，elemental composition and photoelectrochemical properties of the composites were characterized and evaluated by X-ray diffraction（XRD），Fourier transform infrared spectroscopy（FT-IR），X-ray photoelectron spectroscopy（XPS），scanning electron microscopy（SEM），UV-vis diffuse reflectance spectroscopy（UV-vis DRS），steady-state/transient photoluminescence spectroscopy（PL and TRPL），transient photocurrent spectroscopy（TPC） and electrochemical impedance spectroscopy（EIS）.The results showed that the structure of g-C₃N₄/PANI composites was PANI uniformly covered on the surface of g-C₃N₄，and there was a heterojunction structure between g-C₃N₄ and PANI.After coated by PANI，the specific surface area of g-C₃N₄ was significantly increased from 21.31 to 66.13 m²/g，an increase of about 2.10 times，which effectively improved the photocatalytic performance.By optimizing the amount of PANI，the g-C₃N₄/PANI（3%） composite exhibited the best visible light photocatalytic reduction of CO₂ performance，and the space-time yield of CH₃OH reached 3.12 μmol/（g·h），which was 4.27 times that of pure g-C₃N₄.The construction of heterojunction broadened the spectral response range of g-C₃N₄/PANI（3%） composites in the visible light region，effectively promoted the separation of photogenerated carriers，significantly reduced the AC impedance，and significantly improved the charge transfer rate，thereby significantly improving the photocatalytic reduction of CO₂ performance.Gas chromatography analysis showed that the main product of the reaction was CH₃OH，accompanied by a small amount of CO formation，which confirmed that the g-C₃N₄/PANI（3%） composite had good selectivity as a catalyst.After 5 cycles，the space-time yield of CH₃OH was still higher than 2.97 μmol/（g·h），and the activity was maintained above 95%.Finally，the spuce-time energy band structure was obtained by valence band-X-ray photoelectron spectroscopy（VB-XPS） characterization and Mott-Schottky curve analysis.The visible light photocatalytic reduction of CO₂ by g-C₃N₄/PANI composites followed the Type-Ⅱ mechanism.