【摘要】 为满足市场对天然苯甲醛日益增长的需求，采用热聚合法制备石墨相氮化碳（g-C₃N₄）催化剂，对其形貌进行表征；以肉桂醛为模型反应物，在氧气（O₂）作为氧化剂的条件下，分析不同溶剂（乙腈、无水乙醇、N,N-二甲基甲酰胺和甲醇）和催化剂含量等对光催化性能的影响，优化反应条件；通过不同反应物（苯乙烯、肉桂酸和反式-4-苯基-3-丁烯-2-酮）对比试验、理论计算和猝灭试验，探究反应机制。结果表明，g-C₃N₄对选择性氧化肉桂醛制备苯甲醛表现出高效催化性能。在催化剂含量为0.250 mmol、有氧气和光照及溶剂为乙腈条件下，反应效果最佳。反应物分子中的醛基有助于提升苯甲醛选择性，分子内弱相互作用（如范德华力、氢键）和空间结构影响反应物在催化剂表面的吸附和反应路径。反应主要由自由基驱动，超氧阴离子自由基（·O₂^-）是生成苯甲醛的关键活性中间体，光生空穴（h+）对·O₂^-生成起重要作用；羟基自由基（·OH）和单线态氧（¹O₂）主要参与副反应路径，使副产物产生。更多还原

【Abstract】 In order to meet growing market demand for natural benzaldehyde, graphene phase nitrocarbon（g-C₃N₄）catalyst was prepared via thermal polymerization and morphology was characterized. Using cinnamaldehyde as model reactant and oxygen（O₂） as oxidant, effects of different solvents（acetonitrile, ethanol, N,N-dimethylformamide and methanol） and catalyst contents on photocatalytic performance were analyzed to optimize reaction conditions. Reaction mechanism was investigated through comparative experiments with different reactants（styrene, cinnamic acid and trans-4-phenyl-3-buten-2-one）, theoretical calculations and quenching experiments. Results showed that g-C₃ N₄ exhibited high catalytic performance for selective oxidation of cinnamaldehyde to benzaldehyde. Optimal reaction effect was achieved with catalyst content of 0.250 mmol, under oxygen atmosphere with light irradiation, using acetonitrile as solvent. Aldehyde group in reactant molecules contributed to enhancing benzaldehyde selectivity. Intramolecular weak interactions（e.g., van der Waals forces, hydrogen bonding） and spatial structure influenced adsorption of reactants on catalyst surface and reaction pathways.Reaction was primarily driven by free radical, with superoxide anion radical（·O₂^-） being key active intermediate for benzaldehyde formation. Photogenerated holes（h+） played important role in generation of ·O₂^-. Hydroxyl radical（·OH） and singlet oxygen（¹O₂） were mainly involved in side reaction pathway, leading to formation of by-products.更多还原