等离子体Ag/TiO_(2-x)光阳极用于光电催化分解水

Plasma Ag/TiO_(2-x) Photoanode for Photocatalytic Water Splitting

环境污染和破坏以及缺乏足够的清洁能源是目前全球范围内面临的严重的问题。半导体光催化材料因其可以利用太阳能且催化效率高等优点受到广泛关注,是当前研究的热点。二氧化钛(TiO_(2))具有良好的化学稳定性和环境兼容性,是传统半导体光催化材料之一。然而,其仍存在如催化活性易受光生载流子复合的影响及对太阳光的利用率低等缺陷。为了改善TiO_(2)的光电催化性能,使用硼氢化钠(NaBH4)氢化处理以及复合等离子体金属银(Ag)纳米粒子的方法制备得到Ag/TiO_(2)-x异质结构。借助SEM、TEM、XRD、XPS和固体紫外—可见漫反射测试手段对样品的形貌、结构、组成、表面元素以及光吸收性能进行表征。通过光电流密度、电化学阻抗谱以及光电转换效率(IPCE)对样品的光电活性进行测试,结果表明,Ag/TiO_(2-x)异质结构的光电流密度约为TiO_(2)的5倍,且具有较小的阻抗以及较高的IPCE活性。因此,富缺陷TiO_(2)-x和等离子体金属Ag纳米粒子的协同作用能促进其光电催化性能的提升。

Environmental pollution and destruction,as well as the lack of sufficient clean energy,are currently one of the most serious problems facing the world.Semiconductor photocatalytic materials have attracted wide attention due to their advantages of using solar energy and high catalytic efficiency,which are currently the focus of research.Titanium dioxide(TiO_2) is one of the traditional semiconductor photocatalytic materials with good chemical stability and environmental compatibility.However,there are still some limits such as the catalytic activity is easily affected by photo-generated carriers recombination and low utilization rate of sunlight.In order to improve the photoelectrocatalytic performance of TiO_2,Ag/TiO_(2-x) heterostructures were prepared by hydrogenation of sodium borohydride(NaBH4) and composite plasma metal silver(Ag) nanoparticles.The morphology,structure,composition,surface elements and light absorption properties of the samples were characterized by SEM,TEM,XRD,XPS and solid UV-visible diffuse reflection.The photocurrent density,electrochemical impedance spectroscopy and incident photonto-electron conversion efficiency(IPCE) were used to test the photoelectrochemical activity of the samples.The results showed that the photocurrent density of the Ag/TiO_2-xheterostructure was about 5 times higher than that of TiO_2,and it had smaller impedance and higher IPCE activity.Therefore,the synergistic effect of defect-rich Ag/TiO_2-xand plasma metal Ag nanoparticles promotes the improvement of photoelectrocatalytic performance.