Chen Long, Li Wenzhang, Qiu Weixin, He Gaoshuang, Wang Keke, Liu Yang, Wu Qing, Li Jie
School of Chemistry and Chemical Engineering, Central South University, Changsha410083, China.
Hunan Provincial Key Laboratory of Powder Supply, Central South University, Changsha410083, China.
ACS Appl Mater Interfaces. 2022 Oct 26;14(42):47737-47746. doi: 10.1021/acsami.2c13002. Epub 2022 Oct 13.
Hydrogen generation through photoelectrochemical (PEC) technology is one of the most appropriate ways for delivering sustainable fuel. Simultaneously, anisotropic properties will be exhibited by the materials with low crystal symmetry, allowing the tuning of the PEC properties by controlling the crystallographic orientation and exposed facets. Therefore, we synthesized copper tungstate films (CuWO) with highly exposed (100) crystal facets by regulating anions in the precursor solution. According to experimental characterization and density functional theory calculations, the CuWO film with a high exposure ratio of the (100) crystal facet has promoted charge transport with trap-free mode and reduced recombination of electrons and holes. Meanwhile, the oxygen evolution reaction is promoted on the (100) facet because of the relatively low energy barrier. Compared to the CuWO with other mixed exposure facets, CuWO with a highly exposed (100) facet presents a twofold current density (0.38 mA/cm) and one-fifteenth electron transit time (0.698 ms) and also has great stability (more than 6 h). These results provide an easy way to enhance the PEC performance by modulating the exposure facets of the film electrode.
通过光电化学（PEC）技术制氢是提供可持续燃料的最合适方法之一。同时，晶体对称性低的材料会表现出各向异性，这使得通过控制晶体取向和暴露面来调节PEC性能成为可能。因此，我们通过调节前驱体溶液中的阴离子，合成了具有高度暴露的（100）晶面的钨酸铜薄膜（CuWO）。根据实验表征和密度泛函理论计算，（100）晶面暴露率高的CuWO薄膜以无陷阱模式促进了电荷传输，并减少了电子与空穴的复合。同时，由于能量势垒相对较低，（100）晶面上的析氧反应得到促进。与具有其他混合暴露面的CuWO相比，具有高度暴露的（100）晶面的CuWO呈现出两倍的电流密度（0.38 mA/cm）和十五分之一的电子传输时间（0.698 ms），并且还具有很高的稳定性（超过6小时）。这些结果提供了一种通过调节薄膜电极的暴露面来提高PEC性能的简便方法。
