三维自支撑Ni2P纳米片阵列的制备及析氢性能

Preparation and hydrogen evolution performance of three-dimensional self-supported Ni2P nanosheets

开发性能优异的电解水析氢催化剂,减小析氢反应的过电位,降低氢燃料制备成本是电解水制氢技术应用的关键。采用恒电位沉积技术在镍泡沫上制备出镍羟基氧化物(Ni-LDH)纳米片前驱体,再通过低温磷化得到Ni2P纳米片阵列,并作为自支撑电极用于碱性环境下的催化析氢反应。结果表明:调整恒电位沉积时间能够有效调节Ni-LDH纳米片的尺寸及分布;当电沉积时间为7min时,前驱体形成均匀的纳米片阵列且没有明显堆积;经过磷化得到的Ni2P纳米片具有最大的双电层电容(40.1mF/cm2),催化析氢电流密度为10.0mA/cm2时所需的过电位最小(134.0mV),塔菲尔斜率最低(91.0mV/dec);三维自支撑Ni2P纳米片阵列连续测试24h后得到的析氢电流稳定,表明Ni2P纳米片阵列具有很好的析氢稳定性,在碱性环境下有电解水获得氢气的潜力。

Developing excellent catalysts for hydrogen evolution from water electrolysis,reducing the overpotential of hydrogen evolution reaction and decreasing the cost of hydrogen fuel preparation are the keys to the application of hydrogen production from water electrolysis.In this paper,Ni oxyhydroxide(NiLDH)precursor was prepared on Ni form by potentiostatic electrodeposition technology,and then the Ni2P nanosheet arrays were gained by low-temperature phosphorization as self-supported electrode for catalytic hydrogen evolution reaction(HER)in the alkaline condition.The experimental results showed that the size and distribution of Ni-LDH nanosheets could be effectively regulated by changing the electrodeposition time of Ni-LDH.The uniform and unstacked Ni-LDH nanosheets were obtained when the deposition time was 7 min.Consequently,the corresponding Ni2P nanosheets presented the maximum double-layer capacitance(40.1 mF/cm2).The overpotential was lowest(134.0 mV)at the current density of 10.0 mA/cm2,and the Tafle slope wassmallest(91.0 mV/dec).Meanwhile,the hydrogen evolution current of the three-dimensional self-supported Ni2P nanoplate array was still stable after a continuous test for 24 h,indicating that the three-dimensional self-supported Ni2P nanosheet arrays has good stability of hydrogen evolution and a potential of hydrogen evolution by electrolysis of water in thealkaline condition.