Boosting electrochemical water splitting via ternary NiMoCo hybrid nanowire arrays
Boosting electrochemical water splitting via ternary NiMoCo hybrid nanowire arrays
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DOI：
10.1039/c8ta11250a
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发表时间：
2019-02-07
影响因子：
11.9
通讯作者：
Ito, Yoshikazu
中科院分区：
文献类型：
--
作者：
Hu, Kailong;Wu, Mingxing;Ito, Yoshikazu
电化学水分解制氢技术是一项有潜力满足全球对可持续和清洁能源日益增长的需求的技术。然而，开发具有成本效益的催化剂来取代贵金属，如铂或钌，对于大规模制氢仍然至关重要。本研究在1.0 M KOH电解质中合成了一种过渡非贵金属基三元NiMoCo杂化纳米线阵列，作为一种高效的双功能电催化剂。该催化剂具有1.56 V的低电池电压，可实现10 mA cm（-2）的水分解电流密度，并具有长期稳定性，100小时后仅损失5%的初始电流。x射线吸收光谱证实，Co加入到二元Ni-Mo体系中，导致高度混合的化学结合态和调制的电子结构。密度泛函理论（DFT）计算表明，与二元合金相比，三元合金上的Co原子成为催化活性位点，并通过确保反应物与催化剂表面之间更好的相互作用来促进中间体的吸附。本研究为进一步激活二元合金以提高其整体水裂解能力提供了新的方向。
Hydrogen production by electrochemical water splitting is a technology with the potential to meet the growing worldwide demand for sustainable and clean energy. However, the development of cost-effective catalysts to replace noble metals, such as platinum or ruthenium, remains crucial for large-scale hydrogen production. This study presents the synthesis of a transition non-noble metal-based ternary NiMoCo hybrid nanowire array as an efficient bifunctional electrocatalyst for overall water splitting in 1.0 M KOH electrolyte. The catalyst exhibits a low cell voltage of 1.56 V to achieve a water-splitting current density of 10 mA cm(-2) together with long-term stability with only 5% of the initial current lost after 100 hours. X-ray absorption spectroscopy confirms that the addition of Co to the binary Ni-Mo system results in a highly mixed chemical binding state with modulated electronic structures. Density functional theory (DFT) calculations reveal that the Co atoms on the ternary alloy become catalytically active sites and facilitate adsorption of intermediates by ensuring preferable interactions between the reactants and the catalyst surface in comparison to the binary counterpart. This work provides a new direction along which to activate binary alloys to further enhance their catalytic abilities in overall water splitting.