Wang Liqun, Si Wenping, Ye Yuhang, Wang Sihui, Hou Feng, Hou Xinggang, Cai Hongkun, Dou Shi Xue, Liang Ji
Applied Physics Department, College of Physics and Materials Science, Tianjin Normal University, Tianjin 300387, China.
Key Laboratory for Advanced Ceramics and Machining Technology of Ministry of Education, School of Materials Science and Engineering, Tianjin University, Tianjin 300350, China.
ACS Appl Mater Interfaces. 2021 Sep 22;13(37):44184-44194. doi: 10.1021/acsami.1c09665. Epub 2021 Sep 9.
Photoelectrochemical (PEC) water splitting over TiO photoanodes is a promising strategy for hydrogen production due to its eco-friendly, energy-saving, and low-cost nature. However, the intrinsic drawbacks of TiO, ., the too wide band gap and rapid exciton recombination, significantly limit further enhancement of its performance. Herein, we report a TiO nanotube array (TNA), which is implanted by Cu ions and decorated by polymeric carbon nitride (PCN) nanosheets, as a photoanode for the high-efficiency PEC water splitting. In such designed material, Cu-ion implantation can effectively tailor the electronic structure of TiO, thus narrowing the band gap and enhancing the electronic conductivity. Meanwhile, the PCN decoration induces TiO/PCN heterojunctions, enhancing the visible light absorption and accelerating the exciton separation. Upon this synergistic effect, the modified TNA photoanode shows significantly improved PEC capability. Its photocurrent density, solar-to-hydrogen efficiency, and applied bias photon-to-current efficiency achieve 1.89 mA cm at 1.23 V (V reversible hydrogen electrode), 2.31%, and 1.20% at 0.46 V, respectively. Importantly, this modified TNA supported on a meshlike Ti substrate can be readily integrated with a perovskite solar cell to realize unassisted PEC water splitting.
基于TiO光阳极的光电化学（PEC）水分解因其环保、节能和低成本的特性，是一种很有前景的制氢策略。然而，TiO的固有缺点，即宽带隙和快速激子复合，显著限制了其性能的进一步提高。在此，我们报道一种通过铜离子注入并由聚合氮化碳（PCN）纳米片修饰的TiO纳米管阵列（TNA），作为用于高效PEC水分解的光阳极。在这种设计的材料中，铜离子注入可以有效地调整TiO的电子结构，从而缩小带隙并提高电子导电性。同时，PCN修饰诱导形成TiO/PCN异质结，增强可见光吸收并加速激子分离。基于这种协同效应，修饰后的TNA光阳极表现出显著提高的PEC性能。其光电流密度、太阳能制氢效率和外加偏压下的光子到电流效率在1.23 V（相对于可逆氢电极）时分别达到1.89 mA cm²，在0.46 V时分别达到2.31%和1.20%。重要的是，这种支撑在网状Ti基底上的修饰TNA可以很容易地与钙钛矿太阳能电池集成，以实现无辅助的PEC水分解。
