Nanohybrids of Ti3C2Tx MXene with Ni-based structures: Enabling high performance electrocatalyst for water splitting

Abstract

In hydrogen production technologies, the greener way of electrocatalytic water splitting techniques has gained considerable attention in the recent pasts because of utilizing renewable energy as a source and producing hydrogen without any harmful emissions. The hydrogen production via electrocatalytic water splitting techniques majorly depends on the activity of the electrocatalyst. Thus, the key attempts are focused on searching for novel electrocatalysts with high performance and stability to replace the traditional high-cost platinum group metal-based (PGM, such as Pt, RuO2, and IrO2) electrocatalysts. The MXene (Mn+1XnTx) nanostructure of Ti3C2Tx has been significantly considered as an effective and high-performance material for electrocatalytic water splitting applications because of its intrinsic properties, such as large active surface area, hydrophilicity, efficient metallic conductivity, low ion diffusion barriers, higher electron transport, and efficient formation of composites via surface functional groups. However, the utilization of Ti3C2Tx alone as an electrocatalyst has certain drawbacks, such as the possibility of a higher oxidation rate, restacking/aggregation, and structure breakdown during increased surface energy, which significantly affects the benefits for HER and OER. The formation of nanohybrid structures of Ti3C2Tx with different phases of nickel (Ni) significantly influences the enhancement of overall water splitting through multiple mechanisms, such as the strong coupling effect with the interface effect, improved electron and ion transport, increased electrical conductivity, altering the surface energy, increasing the active surfaces, and prohibiting the activation barrier. In this review, we comprehensively explained the impact of Ti-MXene and its performance modification through the various kinds of Ni-based compounds for water splitting applications. Thus, the review is structured into nine main sections of Ti3C2Tx with different kinds of Ni-based compounds, namely (i) Ni single atom, Ni-doped, and Ni nanoparticles; (ii) Ni-containing alloys and composites; (iii) NiO, Ni(OH)2 and Ni-containing bimetallic/trimetallic/high-entropy oxides; (iv) Ni-Phosphide; (v) Ni-Sulphides; (vi) Ni-Selenides; (vii) Ni-based telluride, nitride, and carbide; (viii) Ni-containing LDH and LTH; and (ix) Ni-containing MOF. In each section, the formation of the composite structure and the role of Ti-MXene with Ni-based composites towards efficient HER and OER have been explained in detail. This review provides a comprehensive overview of recent developments, research gaps, and future perspectives on nanohybrids of Ni-based compounds with Ti-MXene.