水热法制备纤维素基CdS纳米复合材料及其光催化性能研究

以棉花为纤维素基质,CdCl_2·21/2H_2O和L-半胱氨酸为原料,采用水热法制备了纤维素基CdS纳米复合材料。以亚甲基蓝(MB)为目标降解物,研究了反应时间和反应温度对该复合材料光催化性能的影响,通过XRD、SEM、FT-IR和UV-VisDRS对不同温度下制得的复合材料进行了结构表征。结果表明,反应温度为影响纤维素基CdS样品光催化活性的关键因素,且对样品中CdS的微观结构有显著影响。当反应温度为120℃时,样品的光催化活性最佳,反应50min对MB溶液的光降解率达到94.78%。经过3次循环其光降解率基本保持不变,表明纤维素基CdS是一种稳定有效的光催化剂。光催化增强机理分析表明,CdS光生电子迁移至纤维素表面,实现了与光生空穴的有效分离,从而增强了材料的光催化性能。

Photocatalytic Performance of Cellulose/CdS Nanocomposites Prepared by Hydrothermal Method

Cellulose/CdS nanocomposites were successfully synthesized via hydrothermal process using natural cotton as cellulose substrates,CdCl2 ·21/2H2 O and L-cysteine as raw materials.The photocatalytic activity of the prepared composites were evaluated by degradation of methylene blue (MB),and the effects of reaction temperature and time on the photocatalytic activity were investigated.The structures and properties of the samples prepared at dif-ferent reaction temperatures were characterized by XRD,SEM,FT-IR and UV-Vis DRS.The results indicated that reaction temperature was a crucial factor for the photocatalytic activity of the samples and had a strong influence on the microstructure of CdS nanoparticles.The composites prepared under 120 ℃ for 12 h showed the highest MB phtoto-degradation rate of 94.78% in 50 min.After three photocatalytic cycles,the degradation rate of cellulose/CdS re-mained 94%,indicating that the cellulose/CdS nanocomposites are stable and durable under considered conditions. The enhanced photocatalytic activity can be ascribed to the efficient transport of photo-induced electrons of CdS to the surface of cellulose,which can reduce the recombination of the photo-induced electrons-hole pairs,thus enhancing the photocatalytic performance.