Cu_2O微晶的可控制备及可见光催化亚甲基蓝降解性能

Controllable Preparation of Cu_2O Microcrystals and Their Visible-light Photocatalytic Activity Toward Degradation of Methylene Blue

以醋酸铜为铜源,柠檬酸钠为形貌导向剂,乙二醇和水为溶剂,采用溶剂热法制备了立方状形貌的Cu2O微晶.利用X射线衍射（XRD）、X射线光电子能谱（XPS）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）和紫外-可见漫反射光谱（UV-Vis DRS）等对Cu2O微晶进行了表征.结果表明,在柠檬酸钠与醋酸铜摩尔比为1.0时,于180℃反应5 h可以制备出尺寸分布在0.6~1.5μm间的均一立方状形貌Cu2O微晶.研究了该微晶对亚甲基蓝（MB）在可见光下降解反应的光催化性能.结果表明,在H2O2存在下,Cu2O微晶（0.3 g/L）在100 min内对30 mg/L MB溶液的降解率可以达到98%.该催化剂经过8次循环使用对MB的降解率仍保持在96%以上,展现了较高的催化活性及良好的稳定性.通过活性物种的分析对催化体系的光催化机理进行了推测.

Cuprous oxide microcubes were prepared by solvothermal method in glycol and water medium using copper acetate as copper source, citrate as a shape directing agent. The samples were characterized by X-ray powder diffraction （ XRD）, X-ray photoelectron spectroscopy （XPS） , scanning electron microscopy （ SEM ） , transmission electron microscopy（TEM） and UV-Vis diffuse reflectance spectroscopy（UV-Vis DRS）. The resuits indicate that uniform cubic Cu2O microcrystals with the size of 0. 6-1.5 μm were synthesized at 180 ℃ for 5 h by controlling the molar ratio of sodium citrate to copper acetate. The visibLe-driven photocatalytic activity of Cu2O microcrystals toward the degradation of methylene blue （MB） was investigated. The results show that after 100 min visible light irradiation, the degradation rate of methylene blue with initial concentration of 30 mg/L reached 98% by using 0. 3 g/L Cu2O microcrystals in the presence of H2O2. The decomposition rate of MB was stilL above 96% even after 8 recycling uses, thus Cu2O microcrystals show high catalytic activity and excellent stability. The photocatalytie mechanism was discussed based on the active species during photocatlytie process.