Shandong Provincial Key Laboratory of Detection Technology for Tumor Markers, School of Chemistry and Chemical Engineering, Linyi University, Linyi 276005, China.
Nanoscale. 2017 Nov 9;9(43):16632-16637. doi: 10.1039/c7nr06001g.
The rising H economy urgently demands active, durable and cost-effective catalysts for the electrochemical hydrogen evolution reaction (HER). However, improving the HER performance of electrocatalysts in alkaline media is still challenging. Herein, we report the development of a nickel hydroxide-cobalt disulfide nanowire array on a carbon cloth (Ni(OH)-CoS/CC) as a hybrid catalyst to significantly enhance the HER activity in alkaline solutions. Benefitting from heterogeneous interfaces in this 3D hybrid electrocatalyst, Ni(OH)-CoS/CC shows superior HER activity with only 99 mV overpotential to drive a current density of 20 mA cm in 1.0 M KOH, which is 100 mV less than that of CoS/CC. Moreover, Ni(OH)-CoS/CC exhibits long-term electrochemical durability with the maintenance of its catalytic activity for 30 h. Density functional theory calculations are performed to gain further insight into the effect of Ni(OH)-CoS interfaces, revealing that Ni(OH) plays a key role in water dissociation to hydrogen intermediates and CoS facilitates the adsorption of hydrogen intermediates and H generation. This work not only develops a promising electrocatalyst for the alkaline HER, but also paves a way to enhance the alkaline HER activity of CoSvia the interface engineering strategy.
在 H 经济兴起的背景下，人们迫切需要高效、稳定且经济实用的电化学析氢反应（HER）催化剂。然而，在碱性介质中提高电催化剂的 HER 性能仍然具有挑战性。在此，我们报告了一种在碳布上生长镍氢氧化物-硫化钴纳米线阵列（Ni(OH)-CoS/CC）的方法，该方法可作为一种混合催化剂，显著提高碱性溶液中的 HER 活性。得益于这种 3D 混合电催化剂中的异质界面，Ni(OH)-CoS/CC 在 1.0 M KOH 中仅需 99 mV 的过电势即可驱动 20 mA cm 的电流密度，比 CoS/CC 低 100 mV。此外，Ni(OH)-CoS/CC 还具有长期的电化学耐久性，其催化活性可维持 30 h。通过密度泛函理论计算进一步深入了解 Ni(OH)-CoS 界面的作用，结果表明 Ni(OH)在促进水分子解离为氢中间体方面发挥着关键作用，而 CoS 则有利于氢中间体的吸附和 H 的生成。这项工作不仅为碱性 HER 开发了一种很有前途的电催化剂，而且还为通过界面工程策略提高 CoS 的碱性 HER 活性开辟了道路。
