Revealing the Bonding Nature and Electronic Structure of Early-Transition-Metal Dihydrides
Revealing the Bonding Nature and Electronic Structure of Early-Transition-Metal Dihydrides
复制标题
DOI：
10.1103/prxenergy.3.013003
复制
发表时间：
2023-05
期刊：
影响因子：
--
通讯作者：
C. Kalha;L. Ratcliff;G. Colombi;C. Schlueter;B. Dam;A. Gloskovskii;Tien-Lin Lee;P. Thakur;Prajna Bhatt;Yujiang Zhu;J. Osterwalder;F. Offi;G. Panaccione;A. Regoutz
中科院分区：
文献类型：
--
作者：
C. Kalha;L. Ratcliff;G. Colombi;C. Schlueter;B. Dam;A. Gloskovskii;Tien-Lin Lee;P. Thakur;Prajna Bhatt;Yujiang Zhu;J. Osterwalder;F. Offi;G. Panaccione;A. Regoutz
氢作为燃料在推动向净零温室气体排放过渡方面发挥着至关重要的作用。为了实现其潜力，获得有效的存储手段至关重要。一种解决方案是使用金属氢化物，由于它们良好的化学吸收性质和有效的储氢。虽然与许多其他能源材料相比，金属氢氧化物看起来很简单，但了解其中氢的电子结构和化学环境仍然是一个关键挑战。这项工作提出了一种新的分析途径，探索这些方面的技术相关的系统，使用硬X射线光电子能谱（HAXPES）的薄膜上的两个原型金属双稳态：YH$_{2-\delta}$和TiH$_{2-\delta}$。利用同步辐射的可调谐性，利用芯能级谱获得了化学态的非破坏性深度分布。结合实验的价带光谱收集在不同的光子能量与理论的见解，从密度泛函理论（DFT）计算，描述的成键性质和作用的d与sp的贡献附近的费米能的状态。此外，提出了一个可靠的确定的生成焓的实验值的金属s带功能的能量位置接近费米能的HAXPES价带谱。
Hydrogen as a fuel plays a crucial role in driving the transition to net zero greenhouse gas emissions. To realise its potential, obtaining a means of efficient storage is paramount. One solution is using metal hydrides, owing to their good thermodynamical absorption properties and effective hydrogen storage. Although metal hydrides appear simple compared to many other energy materials, understanding the electronic structure and chemical environment of hydrogen within them remains a key challenge. This work presents a new analytical pathway to explore these aspects in technologically relevant systems using Hard X-ray Photoelectron Spectroscopy (HAXPES) on thin films of two prototypical metal dihydrides: YH$_{2-\delta}$ and TiH$_{2-\delta}$. By taking advantage of the tunability of synchrotron radiation, a non-destructive depth profile of the chemical states is obtained using core level spectra. Combining experimental valence band spectra collected at varying photon energies with theoretical insights from density functional theory (DFT) calculations, a description of the bonding nature and the role of d versus sp contributions to states near the Fermi energy are provided. Moreover, a reliable determination of the enthalpy of formation is proposed by using experimental values of the energy position of metal s band features close to the Fermi energy in the HAXPES valence band spectra.