陈曦教授课题组在三维光电极的制备及其光电催化水解应用方面取得重要进展，相关成果以“Enhanced performance of photoelectrochemical water oxidation using a three-dimensional interconnected nanostructural photoanode via simultaneously harnessing charge transfer and coating with an oxygen evolution catalyst”（DOI: 10.1016/j.nanoen.2016.05.039）发表在Nano Energy (一区，IF=10.325)。
氢气燃烧时会产生大量的热量，而副产品只有水，没有污染，来源也可以是无穷尽的海水。因此氢气一直被看成是人类向清洁能源过渡的关键要素。光电水解能方便地利用太阳光将水分解为氢气和氧气，制备成本低廉的材料用于光电水解意义重大。研究工作以n-型半导体硅片为电极基底，通过化学方法在硅片上刻蚀出纳米线阵列，之后在阵列上长上另外一种n-型半导体Bi2MoO6 纳米片，由于两者能带匹配，能有效地提高电子空穴的分离效率。这种三维结构不仅能使内反射最大化，提高电极吸收光的能力，同时几乎所有波段的太阳光都能被这两种半导体吸收，提高了太阳能的利用。随后，在该阵列基底上用水热方法修饰上粒径小于5 nm 的铁镍氧化物催化剂，进一步提高光电性能。当其浸入水中并暴露于阳光下时，通过光电化学反应，可借用太阳能将水分解为氢气和氧气，氢氧结合释放能量后的产物，水，也将为海水制备淡水提供途径。
本篇论文主要工作由博士生蔡志雄完成。研究工作得到国家自然科学基金（项目批准号：21375112、21521004），教育部长江学者和创新团队发展计划，福建省海洋与渔业厅海洋高新产业发展专项，福建省重大科技项目等相关项目的支持。
摘要: The most important factors dominating photoelectrochemical (PEC) water splitting performance include light absorption, charge separation and transport, and surface chemical reactions. In order to meet these factors, a novel FexNi1-xO/Bi2MoO6/Si nanowire hierarchical nanostructure was produced using a metal-assisted chemical-etching and hydrothermal growth process, in which Si nanowires were used as backbones, Bi2MoO6 nanosheets as coating, and FexNi1-xO nanoparticles (NPs) as surface catalysts. This integrated three-dimensional (3D) hierarchical nanostructure was applied as a photoanode in a PEC water reaction, and higher photostability and photocurrent density were gained. The excellent PEC performance was due to the 3D hierarchically structural effect, resulting in the enhancement of the surface-to-volume ratio, light harvest and high speed electron transport, and at the same time, terminal FexNi1-xO NPs played the role of the surface catalyst effectively in order to accelerate the water splitting reaction and enhance photostability. Based on such an environmentally friendly hierarchical nanostructure, the study provided an efficient route to improve water-splitting performance and it could also be a model structure for similar electrode materials.
论文链接：http://www.sciencedirect.com/science/article/pii/S2211285516301616 |
