一步法制备二氧化钛-金复合材料及其光解水制氢性能

以钛粉为还原剂,氯金酸为氧化剂,将二者在180 ℃水热反应釜中发生氧化还原反应,最终生成直径800 nm左右的TiO₂,比表面积为3.5 m²/g左右,其表面均匀担载了直径20 nm左右的金纳米颗粒。 采用X射线衍射(XRD)、场发射扫描电子显微镜(FE-SEM)、X射线光电子能谱分析(XPS)、紫外可见漫反射光谱、光电流密度、光催化制氢性能等测试表征了该复合催化剂的结构及性能。 结果表明,一步法制备的复合催化剂形貌规整,TiO₂为锐钛矿晶型,金纳米颗粒的局域表面等离子体共振(LSPR)作用促进了催化剂对可见光有较强的吸收,催化剂催化产氢性能伴随金含量增大存在先增后减规律,可见光下最大产氢速率为0.1 μmol/(g·h),光催化活性表现稳定。

One-Step Synthesis of TiO2-Au Composite and Its Performance for Photocatalytic Hydrogen Evolution

Titanium powders as the reductant and HAuCl₄ were used as the oxidant to prepare TiO₂-Au composite in the hydrothermal reactor at 180 ℃. Finally, the surface of TiO₂ with 800 nm diameter was evenly coated by gold nanoparticles with 20 nm diameter. The specific surface area is about 3.5 m²/g. The structures and properties of the samples were characterized by X-ray diffraction(XRD), field emission scanning electron microscopy(FE-SEM), X-ray photoelectron spectroscopy(XPS), ultraviolet-visible diffuse reflectance spectroscopy, photocurrent density and photocatalytic hydrogen production performance. The morphology of the catalyst synthesized by the one-step method is regular. The final TiO₂ is anatase. The catalyst has a strong absorption in the visible region, benefitting from the local surface plasmon resonance(LSPR) of gold nanoparticles. The hydrogen production performance of the catalyst increases firstly and then decreases with the increase of Au. Under visible light, the maximum hydrogen production rate is 0.1 μmol/(g·h) and the photocatalyst has good stability.