Cheng Zibo, Guan Yeqin, Wen Hong, Li Zhao, Cui Kaixun, Pei Qijun, Wang Shangshang, Pistidda Claudio, Guo Jianping, Cao Hujun, Chen Ping
Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian 116023, China.
Center of Materials and Optoelectronics Engineering, University of Chinese Academy of Sciences, Beijing 100049, China.
J Phys Chem Lett. 2024 Jun 27;15(25):6662-6667. doi: 10.1021/acs.jpclett.4c00874. Epub 2024 Jun 18.
Lithium hydride (LiH), a saline hydride with a hydrogen density of 12.6 wt %, is highly thermostable, which hinders its extensive application in hydrogen storage. In this study, we demonstrate a distinct photodecomposition of LiH under ambient conditions. Ultraviolet-visible (UV-vis) illumination induces hydrogen release and creates surface hydrogen vacancies on LiH. The subsequent H migration enables hydrogen desorption and the accumulation of vacancies at the subsurface, resulting in the generation of metallic Li clusters. Rehydrogenation, on the contrary, can be charged under UV-vis illumination in 1 bar H. Such phenomena show that the thermodynamic and kinetic limits in the re/dehydrogenation of LiH can be broken under illumination, which allows hydrogen storage over the LiH surface at temperatures ∼600 K lower than those of the corresponding thermal process. This work provides new insights into the interaction of semiconducting hydrides and photons and opens an avenue for the development and optimization of materials for hydrogen storage and related photodriven reactions.
氢化锂（LiH）是一种氢密度为12.6 wt%的盐类氢化物，具有高度的热稳定性，这阻碍了它在储氢方面的广泛应用。在本研究中，我们展示了LiH在环境条件下独特的光分解过程。紫外-可见（UV-vis）光照会引发氢释放，并在LiH表面产生氢空位。随后的氢迁移使得氢解吸以及空位在次表面积累，从而导致金属锂簇的生成。相反，再氢化过程可以在1 bar氢气氛围下通过UV-vis光照进行充电。这些现象表明，LiH再氢化/脱氢过程中的热力学和动力学限制在光照条件下可以被打破，这使得在比相应热过程温度低约600 K的情况下，能够在LiH表面进行储氢。这项工作为半导体氢化物与光子的相互作用提供了新的见解，并为储氢及相关光驱动反应材料的开发和优化开辟了一条途径。
