【摘要】 g-C₃N₄是一种典型的聚合物半导体，具有优异的热稳定性、化学稳定性，颇具催化应用前景。采用水热法制备了Bi₂S₃/g-C₃N₄异质结复合材料，通过XRD、SEM、TEM、UV-Vis、FS等手段对样品的组成、形貌、结构和性能进行了表征分析，并模拟了可见光条件下，以甲基橙为降解对象时复合材料的催化性能。结果表明，复合催化剂的异质结结构显著提高了g-C₃N₄的光催化性能：光照3 h时，Bi₂S₃/g-C₃N₄复合材料（Bi₂S₃质量分数达到50%）对甲基橙的降解率达到了97.4%，远超Bi₂S₃的8.9%与g-C₃N₄的38.6%。对Bi₂S₃/g-C₃N₄催化机理进行了研究：Bi₂S₃的加入拓宽了g-C₃N₄的光吸收范围，与g-C₃N₄的异质结结构使光生电子-空穴对的分离效率得到了进一步提高，并延长了光生载流子的寿命，进而提高了g-C₃N₄的光催化性能。更多还原

【Abstract】 As one kind of typical polymer semiconductor, g-C₃N₄ is a promising photocatalyst material with excellent thermal and chemical stability. In this paper, Bi₂S₃/g-C₃N₄ composite catalysts were prepared by hydrothermal method. The composition, morphology, structure and properties of the sample were characterized by XRD, SEM, TEM, UV-Vis and FS, respectively. The catalytic properties of Bi₂S₃/g-C₃N₄ composites were evaluated through degradation of methyl orange（MO） under the condition of simulating solar light. The results showed that the heterojunction structure of the composite catalyst significantly enhanced the photocatalytic performance of g-C₃N₄. The decomposition rate of MO by Bi₂S₃/g-C₃N₄ composite photocatalyst for3 h was far higher than that of pure Bi₂S₃ and g-C₃N₄, which was 8.9% and 38.6%, respectively,with the highest value of 97.4% when the mass fraction of Bi₂S₃ reached 50%. The mechanism of Bi₂S₃/g-C₃N₄ composites with enhanced photocatalytic activity was studied. The addition of Bi₂S₃significantly expanded the light absorption range of g-C₃N₄ and the construction of heterojunction with g-C₃N₄, which could promote the effective separation of photogenerated carriers and extend the carrier life, thus improving the photocatalytic performance of Bi₂S₃/g-C₃N₄ composite catalysts.更多还原