Synergetic effect of Ni substitution and induced porosity: Enhancing the electrocatalytic performance of cobaltite towards OER and MOR in alkaline medium

• Published in: Journal of alloys and compounds Vol. 1002; p. 175375
• Main Authors: Mishra, Prakhar, Parihar, Reena, Singh, Yamini, Singh, Narendra Kumar
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 15-10-2024
• Subjects: Cobaltite; Methanol oxidation; Porosity; Surfactant; Water electrolysis; Water electrolysis; Porosity; Cobaltite; Surfactant; Methanol oxidation
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2024.175375

The quest for sustainable and efficient energy conversion technologies has intensified research into advanced materials for electrochemical reactions, such as the oxygen evolution reaction (OER) and methanol oxidation reaction (MOR). Transition metal oxides have emerged as promising catalysts due to their abundance, low cost, and adjustable electronic properties. Among these, Nickel (Ni)-based compounds are particularly noteworthy for their catalytic activity and stability. This research paper explores the crucial impact of Nickel (Ni) substitution and introducing porosity on the valence states of metal ions and their mass transport in the context of OER and MOR. In this study, we present a step-by-step surfactant (Brij 58) assisted synthesis approach for the preparation of mesoporous Co3O4 and NiCo2O4. The synthesised material has been physiochemically characterised by Fourier transform Infrared Spectroscopy (FTIR), Scanning electron microscopic/Energy-dispersive X-ray spectroscopy (SEM/EDS) and High-resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD), and inductively coupled plasma mass spectrometry (ICP-MS) analyses. Additionally, the impact of these alterations on electrocatalytic activity, reaction kinetics, and electrochemical stability during OER/MOR has been explored by Cyclic Voltammetry (CV), Linear Sweep Voltammetry (LSV), Tafel, Electrochemical Impedance Spectroscopy (EIS) and chronoamperometric experiments. Mesoporous NiCo2O4 exhibits exceptional electrocatalytic performance with current densities of 46.8 mA/cm2 for OER and 214.5 mA/cm2 for MOR at 550 mV. By shedding light on the intricate interplay between metal substitution, porosity, and valence states, this research aims to provide valuable insights for the evolution of enhanced cobaltite electrocatalysts for sustainable water splitting and MOR.
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•This study explores the effects of Ni substitution and porosity on enhancing cobaltite's electrocatalytic performance for OER/MOR.•Porosity is introduced using a modified surfactant (Brij 58) assisted synthesis route.•Enhanced electrochemical performance is elucidated by CV, Tafel plots, Chronoamperometry, and EIS.•Mesoporous NiCo2O4 stands out, displaying exceptional electrocatalytic performance with high current densities in both OER and MOR.•Mechanistic exploration and comparative analyses were pursued to illuminate the intricacies of electrocatalysis.