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评估用于储氢应用的过渡金属（M = Hf、Ti 和 Zr）装饰碳化硅纳

来源：花匠小妙招时间：2025-01-08 03:40

评估用于储氢应用的过渡金属（M = Hf、Ti 和 Zr）装饰碳化硅纳米管（M@SiCNTs）的性能：理论计算的启示

Udochukwu G. Chukwu, Tomsmith O. Unimuke, Youssef Trabelsi, Sopuruchukwu E. Ogbodo, Ali Shawabkeh, Ernest C. Agwamba, Terkumbur E. Gber, Adedapo S. Adeyinka and Hitler Louis*,

摘要

本研究对过渡金属（钛、铪和锆）功能化的碳化硅纳米管（SiCNTs）的储氢能力进行了全面评估。研究采用了 B3LYP/def2svp 理论水平的色散校正 D3(BJ) 密度泛函理论 (DFT) 计算方法。主要目的是评估金属装饰纳米管在高效分子储氢方面的潜力，同时考察过渡金属作为吸附位点的影响。原始 SiCNT 的电子特性能隙为 3.447 eV，在装饰了特定金属（Ti@SiCNT、Zr@SiCNT 和 Hf@SiCNT）后，其电子特性有了显著改善。由此产生的能量值分别为 2.419、1.559 和 1.875 eV。我们进一步研究了 Ti@SiCNT、Zr@SiCNT 和 Hf@SiCNT 在吸附 nH2（n = 1-4）分子过程中的吸附能和储氢能力。吸附能量在 -0.245 至 0.375 eV 之间变化，完全符合美国能源部建议的储氢材料范围。这项研究为了解过渡金属功能化 SiCNT 在储氢应用方面的潜力提供了宝贵的见解。当氢分子被逐步吸附时，吸附能按照 Ti > Zr > Hf 的顺序排列，凸显了 Ti 和 Zr 在多种氢吸附情况下的优异性能。为了评估氢的储存能力和释放情况，我们考虑了重量分析、解吸温度和能量。计算得出 4H2_Ti@SiCNT、4H2_Zr@SiCNT 和 4H2_Hf@SiCNT 的平均解吸能分别为 -3.544、-3.324 和 -3.537eV。随着更多氢分子被移除，解吸能变得更负，这表明所有系统都更有利于氢的释放。根据计算得出的纳米材料的吸附能、电子特性、解吸能和重量百分比（符合 DoE 标准），可以得出结论：所研究的材料在储氢应用方面表现出了极具潜力的特性。

本文章由计算机程序翻译，如有差异，请以英文原文为准。

摘要图片

Assessing the Performance of Transition Metals (M = Hf, Ti, and Zr) Decorated Silicon Carbide Nanotubes (M@SiCNTs) for Hydrogen Storage Applications: Insights from Theoretical Calculations

This study conducted a thorough evaluation of the hydrogen storage capabilities exhibited by silicon carbide nanotubes (SiCNTs) functionalized with transition metals (Ti, Hf, and Zr). The investigation utilized dispersion-corrected D3(BJ) density functional theory (DFT) computational methods at the B3LYP/def2svp level of theory. The primary objective was to evaluate the potential of metal-decorated nanotubes for efficient molecular hydrogen storage while also examining the impact of transition metals as adsorption sites. The electronic characteristics of the pristine SiCNT, featuring an energy gap of 3.447 eV, underwent significant improvement upon decoration with specific metals (Ti@SiCNT, Zr@SiCNT, and Hf@SiCNT). The resulting energy values were 2.419, 1.559, and 1.875 eV, respectively. We further investigated the adsorption energy and hydrogen storage capacity of Ti@SiCNT, Zr@SiCNT, and Hf@SiCNT in the adsorption process of the nH2 (n = 1–4) molecule. The adsorption energies varied from −0.245 to 0.375 eV, falling well within the hydrogen storage material range suggested by the US Department of Energy. This research contributes valuable insights into the potential of transition metal-functionalized SiCNTs as promising candidates for hydrogen storage applications. As hydrogen molecules were stepwise adsorbed, the adsorption energy followed the order of Ti > Zr > Hf, highlighting Ti and Zr’s superior performance in multiple hydrogen adsorption scenarios. To assess hydrogen storage capacity and release, gravimetric analysis, desorption temperatures, and energies were considered. The average desorption energies were calculated as −3.544, −3.324, and −3.537 eV for 4H2_Ti@SiCNT, 4H2_Zr@SiCNT, and 4H2_Hf@SiCNT, respectively. As additional hydrogen molecules were removed, the desorption energy became more negative, indicating a greater favorability for hydrogen release across all systems. Based on the calculated adsorption energy, electronic properties, desorption energy, and weight percent of the nanomaterials, which align with DoE standards, it can be concluded that the studied materials exhibit highly promising attributes for hydrogen storage applications.

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