Photo-Induced Performance Enhancement of Tantalum Nitride for Solar Water Oxidation
Photo-Induced Performance Enhancement of Tantalum Nitride for Solar Water Oxidation
复制标题
DOI：
10.1016/j.joule.2017.09.005
复制
发表时间：
2017-12-20
期刊：
影响因子：
39.8
通讯作者：
Wang, Dunwei
中科院分区：
文献类型：
--
作者：
He, Yumin;Ma, Peiyan;Wang, Dunwei
半导体/电解质界面在定义光催化剂的性能方面发挥着重要作用，但研究很少。在这里，我们报告了一个令人惊讶的观察结果，即光电化学（PEC）条件下该界面上的独特反应导致 Ta3N5 在太阳能水氧化反应中的性能异常增强。仅当引入 Co(OH)(2) 作为水氧化助催化剂时才观察到增强作用。照明和正偏压对于增强效果也至关重要。有人提出，光照诱导的 Od 自由基形成会导致 Ta-O-Co 键的形成，与正常 PEC 条件下在裸 Ta3N5 上更常见的 Ta-O-Ta 键相比，Ta-O-Co 键表现出不太严重的费米能级钉扎。当将高性能析氧催化剂如磷酸钴(Co-Pi)添加到Ta3N5/Co(OH)(2)体系中时，同时实现了高光电流密度和良好的稳定性。
The semiconductor/electrolyte interface plays important roles in defining the performance of photocatalysts but is poorly studied. Here, we report a surprising observation that unique reactions at this interface under photo-electrochemical (PEC) conditions lead to unusual performance enhancement of Ta3N5 for solar water oxidation reactions. The enhancement was only observed when Co(OH)(2) was introduced as a water oxidation co-catalyst. Illumination and positive bias were also critical to the enhancement. It was proposed that Od radical formation induced by illumination results in the formation of Ta-O-Co bonds, which exhibit less severe Fermi-level pinning when compared with Ta-O-Ta bonds that are more commonly observed on bare Ta3N5 under normal PEC conditions. When a high-performance oxygen evolution catalyst such as cobalt phosphate (Co-Pi) was added to the Ta3N5/Co(OH)(2) system, high photocurrent densities and good stability were achieved simultaneously.