Synergy of Nb Doping and Surface Alloy Enhanced on Water–Alkali Electrocatalytic Hydrogen Generation Performance in Ti‐Based MXene

Abstract

Presented are the theoretical calculation and experimental studies of a Ti 3 C 2 T x MXene‐based nanohybrid with simultaneous Nb doping and surface transition metal alloy modification. Guided by the density functional theory calculation, the Nb doping can move up the Fermi energy level to the conduction band, thus enhancing the electronic conductivity. Meanwhile, the surface modification by Ni/Co alloy can moderate the surface M–H affinity, which will further enhance the hydrogen evolution reaction (HER) activity. A series of Ni/Co alloy attached on Nb‐doped Ti 3 C 2 T x MXene nanohybrids (denoted as NiCo@NTM) are successfully prepared. As expected, the Ni 0.9 Co 0.1 @ NTM nanohybrids present an extraordinary HER activity in alkaline solution, which only needs an overpotential (η) of 43.4 mV to reach the current density of 10 mA cm −2 in 1 m KOH solution and shows good stability. The performance of the Ni 0.9 Co 0.1 @ NTM nanohybrids is comparable to the commercial 10% Pt/C electrode (34.4 mV@10 mA cm −2 ) and is better than most state‐of‐the‐art Pt‐free HER catalysts. Inspired by the facile synthesis process and chemical versatility of both MXene and transition metal alloys, the nanohybrids reported here are promising non‐noble metal electrocatalysts for water–alkali electrolysis.

Rational Design of Two-Dimensional Transition Metal Carbide/Nitride (MXene) Hybrids and Nanocomposites for Catalytic Energy Storage and Conversion

“…Du et al modified the Ti3C2Tx surface with Ni/Co alloyed QDs to reduce the overly strong Ti-H interaction. 177 Nb was also doped into Ti3C2Tx to raise the Fermi level to the conduction band, improving the electronic conductivity of the Ti3C2Tx support.…”

Rare-earth-regulated Ru-O interaction within the pyrochlore ruthenate for electrocatalytic oxygen evolution in acidic media

“…S4. To compare the intrinsic activities, all the current densities were normalized to the ECSA ( Figs S5, S6) [32]. As shown in Fig.…”

Design of efficient electrocatalysts for hydrogen evolution reaction based on 2D MXenes

“…The substitution is another common strategy to improve the performance of the catalyst. Yan et al used niobium (Nb) to substitute Ti atoms in Ti 3 C 2 T x -MXenes, providing extra electrons to raise the Fermi energy level to the conduction band, thus improving the charge transport properties [65]. At the same time, Ni/Co alloy was doped with MXenes using self-assembly and low-temperature reduction process, which adjusted the affinity between the surface ''M" and H* to a moderate equilibrium position.…”