Enhanced electrocatalytic activity by chemical nitridation of two-dimensional titanium carbide MXene for hydrogen evolution

Abstract

We report a strategy to turn non-electrocatalytic 2D-titanium carbide MXene (Ti2CTx) into a highly active electrocatalyst by nitridation with sodium amide (NaNH2).

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

“…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) …”

“…Therefore, many research groups have attempted to improve electrocatalytic properties through modification of the terminal functional groups on the basal plane of MXenes, and as a representative study, the HER performance of Mo 2 CT x is improved through controlling the terminal functional group coverages on the basal planes by using various etchants . In addition, it has been reported that nonelectrocatalytic Ti‐based MXene can be turned into an active electrocatalysts for water splitting (both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER)) by chemical modifications . Besides, transition‐metal modification of the surface of the Ti‐based MXene was shown to greatly benefit the performance of the electrocatalyst .…”

Solution-phase phosphorus substitution for enhanced oxygen evolution reaction in Cu2WS4

“…Although a certain degree of defect formation is benecial for catalytic activity, excessive defects can hinder performance by reducing electrical conductivity. 40,41 Because Cu 2 WS 3.2 P 0.8 was shown to have many amorphous regions and a heavily strained lattice in the previously discussed XRD and TEM data, we suspect that the electrical conductivity is negatively impacted as a result. However, the catalytic activity of Cu 2 WS 3.6 P 0.4 (onset potential 1.70 V vs. RHE at 10 mA cm À2 with Tafel slope 272 mV dec À1 ) sample reveals that $6 at% P is not enough to utilize the basal planes of Cu 2 WS 4 for OER activity.…”

MXene‐Based Nanocomposites for Energy Conversion and Storage Applications

“…Typically, the CoP‐3D MXene hybrid exhibits high electrocatalytic activity for oxygen and hydrogen in alkaline electrolyte. An's group reported a strategy to transform the non‐electrocatalytic Ti 2 CT x into active electrocatalyst by nitriding the Ti 2 CT x with sodium amide (NaNH 2 ) . The nitrided‐Ti 2 CT x (N‐Ti 2 CT x ) showed high electrocatalytic activity at 10 mA cm −2 and the overpotential for hydrogen evolution was measured to be −215 mV vs. NHE.…”