CdS/g-C_3N_4复合材料的制备及其光催化性能研究

Study on the preparation and photocatalytic performance of CdS/g-C_3N_4 composite catalyst

采用沉淀法制备CdS/g-C_3N_4复合光催化剂.利用XRD、SEM、FTIR、EDS、UV-Vis-DRS等对合成样品的结构、形貌、组分及光吸收性能进行表征.通过甲基橙(MO)水溶液的光催化降解评价产品的光催化活性.结果表明:CdS/g-C_3N_4复合光催化剂由CdS和g-C_3N_4两相组成,将g-C_3N_4与CdS复合明显增强了光催化活性,其中,质量比为5∶3的CdS/g-C_3N_4光催化活性最高,紫外光照150 min,MO降解率达97.88%,MO表观降解速率常数分别是纯CdS和g-C_3N_4催化时的6.24和11.91倍.稳定性测试结果表明CdS/g-C_3N_4复合光催化剂在光催化反应中拥有优异的稳定性和可重复性.

CdS/g-C3N4 composite photocatalyst was prepared by a precipitation method. The structure, morpholo- gy, component and spectral properties of the as-obtained products were characterized by means of XRD, SEM, FTIR, EDS and UV-Vis-DRS, respectively. The photocatalytic activities of the products were evaluated by the degradation of methyl orange （MO） aqueous solution. The results showed that CdS/g-C3N4 composite photocatalyst was comprised of CdS nanoparticles and g-C3N4 thin film. The incorporation of g-C3N4 film into CdS nanoparticles could significantly improve the photocatalytic activity of both. The CdS/g-C3N4 composite photocatalyst exhibited the best photocatalytic acitvity when the mass ratio of CdS to g-C3N4 is 5 ： 3. The degradation rate of MO reached 97.88% after 150 rain of UV irradiation.The apparent degradation rate constant of MO with 5 ： 3CdS/g-C3N4 composite photocatalyst was 6.24 and 11.91 times higher than that with pure CdS and g-C3N4, respectively. The results of stability test showed that 5 ： 3CdS/g-C3N4 composite photocatalyst had an outstanding stability and repeatability in photocatalytic reaction.