Cu_2O/(rGO-TiO_2)复合薄膜的制备及其光催化产氢性能

Fabrication of a Cu_2O/(rGO-TiO_2) Composite Film for Efficient Photocatalytic Hydrogen Production

在氧化亚铜(Cu_2O)和二氧化钛(TiO_2)的复合材料中,引入石墨烯(rGO),制备出新型的Cu_2O/(rGO-TiO_2)光催化薄膜.首先通过电化学沉积法在铜片上制备Cu_2O;然后通过水热法在TiO_2悬浊液中,将氧化石墨烯(GO)还原为rGO,并制备出rGO-TiO_2复合光催化颗粒;最后将rGO-TiO_2涂覆在Cu_2O表面制备出Cu_2O/(rGO-TiO_2)光催化剂.催化剂的形貌和表面特征采用扫描电镜(SEM)、透射电镜(TEM)进行表征,材料晶体结构采用X射线衍射(XRD)和拉曼光谱(Raman)分析,其光学特性采用紫外-可见漫反射分光光度计(UV-Vis DRS)、荧光分光光度计(PL)进行表征.结果表明:与Cu_2O-TiO_2比较,Cu_2O/(rGO-TiO_2)薄膜表现出很强的光催化产氢性能,其中负载rGO质量分数为1.0%的样品Cu_2O/(1.0%rGO-TiO_2)薄膜在300 W氙灯的照射下,对体积分数为20%的甲醇溶液进行光催化反应,其产氢速率(326 mmol·h-1·m-2)是Cu_2O-TiO_2薄膜产氢速率的3.5倍.此外,分别探讨牺牲剂类型和pH对Cu_2O/(rGO-TiO_2)光催化薄膜的光催化产氢活性的影响.结果表明:在体积分数为20%的甲醇水溶液(中性)中,该催化剂的产氢性能最佳.

A novel and environmentally friendly photocatalyst film,Cu2O/（rGO-TiO2）,was synthesized by introducing rGO into Cu2O and TiO2 composite. The composite catalyst film had a multi-layer structure and could effectively produce hydrogen and decompose organic matters simultaneously under solar light irradiation. Firstly,the Cu2O was prepared by electrochemical deposition. Then the GO was reduced to rGO in TiO2 suspension to fabricate the rGO-TiO2 particles. Finally,the rGO-TiO2 suspension was painted on the surface of Cu2O. The morphology of as-prepared composite film was analyzed with SEM and TEM; its crystal structure was examined with XRD and Raman and its optical characteristics was investigated with UV-Vis DRS and PL. The composite film was applied for hydrogen generation with 20%（volume percentage） methanol under 300 W Xe lamp irradiation. Compared with Cu2OTiO2 film,the photocatalytic hydrogen production of the composite film（326 mmol·h^-1·m^-2） was improved（3.5 folds） significantly after coupling 1.0%（mass percentage） rGO to Cu2O-TiO2. Besides,the photocatalytic hydrogen productivity was also examined with different electron donors and with 20% methanol at different pH. The results showed that the highest hydrogen production rate was achieved in 20%（volume percentage） methanol with neutral pH.