CuCrO2的合成及其复合催化剂的光催化性能

Preparation of CuCrO_2 and the photocatalytic properties of its composites

以硝酸铬和硝酸铜为原料,通过半湿法经两种不同路径合成了CuCrO2半导体物质。分别采用热重-差示扫描(TGDSC)、X射线衍射(XRD)、紫外-可见漫反射(UV-vis DR)、扫描电镜(SEM)及X射线光电子能谱(XPS)对样品进行了表征分析。确立了以氨水为Cr3+沉淀剂制得的氢氧化铬沉淀中加入硝酸铜溶液是合成CuCrO2较适宜的路径。借助TG-DSC和XRD的分析结果确立前驱体在热处理的过程中,含Cr物相的变化历程为Cr(OH)3→CuCrO4→CuCr2O4→CuCrO2。通过机械研磨的方法合成了CuCrO2-WO3和CuCrO2-ZnO复合型催化剂,对其进行了XRD、SEM和XPS表征分析,并测试了复合催化剂的光催化活性。结果表明,与单独使用CuCrO2相比,无论是以高压汞灯,还是以氙灯为光源,CuCrO2-WO3和CuCrO2-ZnO的光催化产氢活性都有显著提高。

Delafossite CuCrO2 was prepared with Cr（ NO3）3 and Cu（ NO3）2 by the semi-wet method via two different routes. The samples were characterized with thermogravimetry-differential scanning calorimetry,X-ray diffraction, diffuse reflectance ultraviolet-visible spectroscopy, scanning electron microscopy and X-ray photoelectron spectroscopy techniques. It was shown that addition of Cr（ OH）3 precipitated with aqueous ammonia solution into aqueous Cu（ NO3）2 solution is a suitable route to synthesize CuCrO2. In the calcination process,the precursor transformed into CuCrO2 in the sequence： Cr（ OH）3 → CuCrO4 → CuCr2O4 → CuCrO2,as verified by the TG-DSC and XRD results. The composites of CuCrO2-WO3 and CuCrO2-ZnO prepared by the grinding method showhigher activity than CuCrO2 in the photocatalytic splitting of water into hydrogen under the irradiation of a high-pressure mercury lamp or a xenon lamp.