泡沫镍铁合金自支撑NiFeOOH纳米片的制备及析氧性能研究

NiFeOOH Nanosheets Self-supported on the NiFe Alloy Foam for Oxygen Evolution Reaction

电催化析氧反应(OER)是电解水制氢的重要半电池反应.然而,OER的缓慢动力学仍需研究高效的电催化剂.在非贵金属催化剂中,NiFe基材料是OER催化剂研究热点.我们通过食人鱼溶液简单一步浸渍刻蚀法将不同Fe含量的泡沫NiFe合金进行氧化,制备了表面具有纳米片形貌的NiFeOOH自支撑电催化剂,并深入研究其电催化析氧性能.通过SEM、XRD、XPS等对电催化剂的形貌结构及成分进行表征,证实了三维多孔基底上NiFeOOH纳米片结构的形成.由于高价镍、铁物种的存在以及二维纳米片结构的生成,NiFeOOH/NF的析氧性能大幅度提高,在10 mA∙cm^(−2)的电流密度下过电位仅155.68 mV,Tafel斜率为88.2 mV∙dec^(-1).这为研制高效、耐用的自支撑非贵金属电极提供了新思路.

The electrocatalytic oxygen evolution reaction(OER)is a critical half-cell reaction for hydrogen production via water electrolysis.However,the practical OER suffers from sluggish kinetics and thus requires efficient electrocatalyst.Among the non-noble metal catalysts,NiFe-based materials represent one of the most active classes of OER catalysts.In the present work,the self-supporting NiFeOOH catalysts with nanosheet morphology were prepared by oxidation of NiFe alloy foam(NF)via a simple one-step impregnation etching method using piranha solution and their OER performances in alkaline were studied in depth.The morphology,structure and composition of electrocatalysts were characterized by SEM,mapping,XRD and XPS,which confirmed the formation of NiFeOOH nanosheet structure on 3D porous substrate.Due to the presence of high-valence Ni,Fe species and the formation of two-dimensional nanosheet structure,the OER performance of NiFeOOH/NF is greatly improved,the overpotential is only 155.68 mV at 10 mA∙cm−2,Tafel slope is only 88.2 mV∙dec^(-1).The results provide a new idea for the development of efficient and durable self-supporting non-noble metal electrode.