Cu2O/Cu2S 复合材料制备及可见光催化降解甲基橙的研究

通过水热法制备Cu₂O/Cu₂S 复合材料对甲基橙(MO) 进行光催化降解实验。在Cu₂O 中引入S 元素, 通过改变Cu/S 投加摩尔比, 从而得到不同Cu/S 的复合材料。利用XRD、SEM、UV-vis、EIS 等手段对材料进行表征, 并对MO 进行光催化降解实验。XRD 结果表明, 随着S 含量的增多, Cu₂S 的衍射强度逐渐上升, Cu₂O 的f111g 晶面衍射强度逐渐降低。SEM 结果表明Cu₂S 能较好地包覆在Cu₂O 八面体的表面。通过UV-vis 和EIS 结果计算得知,复合材料带隙为1.49 eV, 电荷转移电阻大幅降低。降解实验结果表明复合材料最佳Cu/S 投加摩尔比为15 : 1, 其在100 min 时对MO (100 mL, 10 mg/L) 降解率达到91.4%, 明显高于纯Cu₂O 对于MO 的降解率(60.3%)。猝灭实验表明了?OH 和 ?O₂ ^-在光催化过程中起到主要作用。

Preparation of Cu2O/Cu2S Composite and Study on Visible PhotocatalyticDegradation of Methyl Orange

Photocatalytic degradation of methyl orange (MO) by Cu₂O/Cu₂S composite material prepared by hydrothermal method wasstudied. By introducing S element into Cu₂O and changing the molar ratio of Cu/S, different Cu/S composites were obtained. Thematerials were characterized by XRD, SEM, UV-vis and EIS, and photocatalytic degradation of MO was carried out. XRD results showthat with the increase of S content, the diffraction intensity of Cu₂S increases gradually, while the diffraction intensity of f111g planeof Cu₂O decreases gradually. SEM results show that Cu₂S can coat the surface of Cu₂O octahedron well. According to UV-vis andEIS results, the band gap of the composite is 1.49 eV, and the charge transfer resistance is greatly reduced. The results of degradationexperiments show that the optimum Cu/S molar ratio is 15 : 1, and the degradation rate of MO (100 mL, 10 mg/L) reaches 91.4% at 100min, which is significantly higher than that of pure Cu₂O (60.3%). The quenching experiments show that ?OH and ?O₂^- play a majorrole in the photocatalytic process.