Ali Wajid, Li Xinyang, Yang Yuxiao, Li Na, Huang Bo, Wu Chengzhang, Ding Shujiang
School of Chemistry, Xi'an Key Laboratory of Sustainable Energy Materials Chemistry, State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, P. R. China.
College of Chemistry and Materials Science, Zhejiang Normal University, Jinhua 321004, Zhejiang, China.
ACS Appl Mater Interfaces. 2023 Aug 2;15(30):36167-36178. doi: 10.1021/acsami.3c05308. Epub 2023 Jul 19.
Magnesium hydride (MGH) is a high-capacity and low-cost hydrogen storage material; however, slow kinetic rates, high dehydrogenation temperature, and short cycle life hindered its large-scale applications. We proposed a strategy of designing novel delaminated 3D bimetal MXene (-TiNbCT) nanostructure to solve these problems. The on-set dehydrogenation temperature of MGH@-TiNbCT composition was reduced to 150 °C, achieving 7.2 wt % of hydrogen releasing capacity within the range of 150-250 °C. This composition absorbed 7.2 wt % hydrogen within 5 min at 200 °C and 5.5 wt % at 30 °C within 2 h, while the desorption capacity (6.0 wt %) was measured at 275 °C within 7 min. After 150 cycles at 250 °C, the 6.5 wt % capacity was retained with negligible loss of hydrogen content. These results were attributed to the catalytic effect of -formed TiH/NbH nanocatalysts, which lead to dissociate the Mg-H bonds and promote of kinetic rates. This unique structure paves great opportunities for designing of highly efficient MGHs/MXene nanocomposites to improve the hydrogen storage performance of MGHs.
氢化镁（MGH）是一种高容量且低成本的储氢材料；然而，缓慢的动力学速率、较高的脱氢温度以及较短的循环寿命阻碍了其大规模应用。我们提出了一种设计新型分层三维双金属MXene（-TiNbCT）纳米结构的策略来解决这些问题。MGH@-TiNbCT组合物的起始脱氢温度降低到了150℃，在150 - 250℃范围内实现了7.2 wt%的氢释放容量。该组合物在200℃下5分钟内吸收了7.2 wt%的氢，在30℃下2小时内吸收了5.5 wt%的氢，而在275℃下7分钟内测得解吸容量为6.0 wt%。在250℃下进行150次循环后，保留了6.5 wt%的容量，氢含量损失可忽略不计。这些结果归因于形成的TiH/NbH纳米催化剂的催化作用，其导致Mg - H键解离并提高了动力学速率。这种独特的结构为设计高效的MGHs/MXene纳米复合材料以改善MGHs的储氢性能提供了巨大机遇。
