Introducing an inexpensive non-noble metal electrocatalyst is an ongoing challenge in oxygen evolution reaction (OER). Here, a bimetallic cobalt-nickel-based catalyst is introduced by metal loading over hydroxyapatite multiwalled carbon nanotube substrate (Co-Ni/HA-MWCNTs). The proposed catalyst is promising and inexpensive and could be favorably applied in water electrolyzing systems. The HA-MWCNTs substrate was produced via the solid-state approach and the loading of Ni and Co species was achieved via the simple impregnation process. Structural characterization of the catalyst was achieved using transmission electron microscopy (TEM), X-Ray diffraction (XRD), and energy-dispersive X-ray analysis (EDX). Electrochemical efficiency of the catalyst for the OER was concluded from low onset potential at 1.50 V (vs RHE) with Tafel slope of 41.8 mV dec⁻¹. In comparison with the HA-free catalyst (Co-Ni/MWCNTs), the Co-Ni/HA-MWCNTs catalyst exhibits an excellent long-term stability up to 10,000 s to bear the current density of 10.0 mA cm⁻².

Graphical Abstract

引入廉价的非贵金属电催化剂是氧释放反应（OER）中的一个持续挑战。在此，通过在羟基磷灰石多壁碳纳米管基底（Co-Ni / HA-MWCNT）上进行金属负载，引入了双金属钴镍基催化剂。所提出的催化剂是有前途且廉价的，并且可以有利地应用于水电解系统中。HA-MWCNTs基材是通过固态方法生产的，而Ni和Co物种的负载量是通过简单的浸渍工艺实现的。使用透射电子显微镜（TEM），X射线衍射（XRD）和能量色散X射线分析（EDX）实现了催化剂的结构表征。OER催化剂的电化学效率由1.50 V（vs RHE）的低启动电位和41.8 mV dec的Tafel斜率得出。^-1。与不含HA的催化剂（Co-Ni / MWCNTs）相比，Co-Ni / HA-MWCNTs催化剂在长达10,000 s的时间内表现出出色的长期稳定性，可承受10.0 mA cm ^-2的电流密度。

图形概要