Phosphorized MXene-Phase Molybdenum Carbide as an Earth-Abundant Hydrogen Evolution Electrocatalyst

Abstract

MXenes with good conductivity and hydrophilicity are a new family of potential electrocatalysts (e.g., for hydrogen evolution). However, pristine MXenes usually show unsatisfactory catalytic activity compared with traditional platinum group metal electrocatalysts. We introduce both phosphorus and oxygen into Mo 2 CT x MXenes through a simple phosphorization course. The phosphorized Mo 2 CT x MXenes exhibit significantly improved electrocatalytic performance toward hydrogen evolution reaction compared with pristine Mo 2 CT x MXenes, with a dramatic decrease in overpotential (more than 100 mV at 10 mA cm −2 ). Theoretical computation suggests that P and O doped Mo 2 CT x MXenes possess a metallic band structure and an optimal hydrogen adsorption, which lead to improved conductivity and electrocatalytic kinetics, respectively. This work not only advances the understanding of property-tuning of the latest two-dimensional MXene materials but also paves the way for the development of MXene-based materials that can be applied in the field of energy conversion and storage.

Precious‐Metal‐Free Electrocatalysts for Activation of Hydrogen Evolution with Nonmetallic Electron Donor: Chemical Composition Controllable Phosphorous Doped Vanadium Carbide MXene

“…Thus, a simple post‐chemical treatment or modification on the basal plane of MXenes makes it possible to improve electrocatalytic performances as one of activation processes on HER without consideration of inactive surface, further sample preparations and morphological control. Not only, these results are the first attempt in V 2 CT x MXene electrocatalysts, but also the electrocatalytic performances are comparable to previously reported results, such as Ti‐based and Mo‐based MXene electrocatalysts . Our work shows that the composition tuning approach with nonmetallic electron donor doping is powerful way to design active and stable electrocatalysts for HER, further to verify the importance of electron donor doping in other MXene based materials for HER.…”

“…Especially, CP bonds at 283.5 eV newly appeared after heat treatment at 300 °C and gradually increased further as phosphorization reaction temperature increased up to 500 °C. This proves that such heteroatom can be doped or substituted not only in surface terminated O but also in V defect sites, which are typically observed in other carbon materials and MXene phases . In contrast, the intensities of the CO (286.3 eV) and COOH (288.8 eV) peaks remain more or less constant.…”

“…As shown in the summary of recent reports in Figure f, very high overvoltage (>−600 mV) is required in case of Ti‐ (Ti 2 CT x and/or Ti 3 C 2 T x ), V‐based MXene catalysts which are not chemically modified, and Mo‐based (Mo 2 CT x and Mo 2 TiC 2 T x ) or its composite material (MoS 2 /Ti 2 CT x ) . However, previous results mentioned so far show that electrocatalytical activation of the most frequently used Ti‐based MXene can easily induce electrochemical activation via chemical modification, likely simple doping or complexing with heteroatoms such as nitrogen (N) …”

Hetero‐MXenes: Theory, Synthesis, and Emerging Applications

“…Reproduced with permission. [ 218 ] Copyright 2018, American Chemical Society. e) Synthesis of P‐doped V 2 CT x by using triphenyl phosphine.…”

“…Generally, simple substance phosphorus can be directly used to modify the as‐synthesized MXene flakes by various methods. [ 198,217,218,220 ] Meng et al. established a liquid‐solid‐phase assembly approach to anchor black phosphorus (BP) QDs on Ti 3 C 2 nanosheets by a facile solution mixing (Figure 13c).…”