Fabrication of nickel nanoparticles anchored on a 2D double transition metal MXene for efficient hydrogen and oxygen evolution reactions

Abstract

Creating cost-effective and high-performing bifunctional electrocatalysts is a viable alternative to expensive noble metal electrocatalysts for water-splitting applications. A double transition metal MXene (Mo2TiC2Tx) has recently shown exceptional electrocatalytic activity because of its high conductivity, hydrophilicity, mechanical stability, electron mobility, and rich surface chemistry. In this study, we have created efficient bifunctional electrocatalytic properties of nano Ni decorated Mo2TiC2Tx MXene (Ni–Mo2TiC2Tx). The efficient and homogeneous incorporation of Ni on the 2D Mo2TiC2Tx surface and between the layers demonstrates remarkable electrocatalytic efficiency for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). Among the different combinations, the 15 mmol Ni–Mo2TiC2Tx showed lower overpotential for the HER (ƞ10 = 153.9 mV) and OER (ƞ10 = 200.5 mV). Moreover, the Ni–Mo2TiC2Tx based electrocatalysts exhibit satisfactory electrochemical stability up to 5000 cycles. During the HER and OER process, Ni and Mo cations form a new oxy-hydroxide layer on the surface in the OH− environment indicating a faster surface self-reconstruction process of the surface structure and Ni/Mo oxy-hydroxide layer interacts with O and H atoms of adsorbed water and thus leading to superior HER and OER activity. This study introduces a straightforward and effective approach to creating a new category of MXene heterostructures, which significantly boosts the performance and durability of catalysts for the HER and the OER showing promise for future applications.