Pandey Deepak K, Kagdada Hardik L, Materny Arnulf, Singh Dheeraj K
Department of Basic Sciences, Institute of Infrastructure Technology Research And Management, Ahmedabad 380026, India.
Department of Physics and Earth Sciences, Jacobs University Bremen, Bremen 28759, Germany.
J Phys Chem A. 2021 Apr 1;125(12):2653-2665. doi: 10.1021/acs.jpca.0c10912. Epub 2021 Mar 18.
Hydrogen energy has received significant attention in the renewable energy sector due to its high energy density and environmentally friendly nature. For the efficient hydrogen generation from water, the hydrogen evolution reaction (HER) has to be optimized, which requires a highly efficient electrocatalyst. In this work, a hybrid structure of the ionic liquid (IL) 1-ethyl-3-methylimidazolium trifluoromethanesulfonate (Cmim TfO) and (TiO) nanoclusters with = 2-12 has been investigated in the pursuit of new catalyst materials for effective HER. We have employed state-of-the-art density functional theory (DFT) computations to depict the HER catalytic performance of IL/(TiO) hybrid systems through Gibbs free energy (Δ) and an exchange-current-based "volcano" plot. We have explored the effect of the TiO nanoclusters on the structural and electronic characteristics of the IL, calculating the adsorption energy, the energies of the highest occupied (HOMO) and lowest unoccupied molecular orbitals (LUMO), the HOMO-LUMO band gap , and the work function ϕ. The variation in size of the TiO nanocluster in the IL/(TiO) hybrid system was found to have a significant influence on the electronic properties. The obtained results suggest that the Δ of the hydrogen adsorption is remarkably close to the ideal value (0 eV) for the IL/(TiO) system, which also reflects from the volcano plot, suggesting that this complex is the best HER catalyst among the studied systems; it might be even better than the traditional Pt-based catalyst. Thus, the present work suggests ways for the experimental realization of low-cost and multifunctional IL-based hybrid catalysts for clean and renewable hydrogen energy production.
由于氢能具有高能量密度和环境友好的特性，其在可再生能源领域受到了广泛关注。为了实现高效的水制氢，析氢反应（HER）必须得到优化，这就需要一种高效的电催化剂。在这项工作中，为了寻找用于有效析氢反应的新型催化剂材料，研究了离子液体（IL）1-乙基-3-甲基咪唑三氟甲磺酸盐（Cmim TfO）与壳层厚度为2-12的（TiO）纳米团簇的混合结构。我们采用了最先进的密度泛函理论（DFT）计算，通过吉布斯自由能（Δ）和基于交换电流的“火山”图来描述IL/（TiO）混合体系的析氢催化性能。我们研究了TiO纳米团簇对IL的结构和电子特性的影响，计算了吸附能、最高占据分子轨道（HOMO）和最低未占据分子轨道（LUMO）的能量、HOMO-LUMO带隙以及功函数ϕ。结果发现，IL/（TiO）混合体系中TiO纳米团簇尺寸的变化对电子性质有显著影响。所得结果表明，IL/（TiO）体系的氢吸附吉布斯自由能（Δ）非常接近理想值（0 eV），这也从“火山”图中得到反映，表明该复合物是所研究体系中最佳的析氢催化剂；它甚至可能比传统的铂基催化剂更好。因此，本研究为低成本、多功能的基于离子液体的混合催化剂用于清洁和可再生氢能生产的实验实现提供了方法。
