Nanostructure of Cr₂CO₂ MXene Supported Single Metal Atom as an Efficient Bifunctional Electrocatalyst for Overall Water Splitting

Abstract

Nanostructure-supported single-atom bifunctional catalysts can reduce the usage of catalyst and improve the catalytic activity compared with unifunctional catalysts. Developing effective bifunctional electrocatalysts for water splitting is one of the central issues to the area of renewable energy. Herein, we report a single transition-metal atom anchoring on the Cr2CO2 MXene surface as bifunctional eletrocatalyst for water splitting through density functional theory calculations. Results show that Ni anchored on Cr2CO2 (Ni/Cr2CO2) MXene exhibits satisfactory catalytic activity producing low overpotentials of 0.16 and 0.46 V for HER and OER, respectively. Large amounts of electrons were transferred from Ni to the surface O* of Cr2CO2, promoting the binding strength between Ni and Cr2CO2 (binding energy is −5.16 eV). The ultrahigh Ni oxide formation pressure (O2 pressure is higher, at 3 × 1019Pa) ensures the stability of Ni/Cr2CO2 during electrocatalytic water splitting. Moreover, ab initio molecular dynamics simulations and climbing nudged elastic band calculations suggest that Ni atom can be stably immobilized on Cr2CO2 substrate to prevent its aggregation to form Ni3 and Ni4 clusters. In addition, the possible synthesis route is predicted for a Cr2CO2-supported Ni single-atom catalyst (SAC) system showing that Ni/Cr2CO2 can be experimentally synthesized. This work shows that Cr2CO2-supported Ni SAC can be a potential catalyst for water splitting and therefore provides an opportunity for energy conversion.

Cu Anchored Ti2NO2 as High Performance Electrocatalyst for Oxygen Evolution Reaction: A Density Functional Theory Study

“…MXenes, a novel new family of two‐dimension material, have been combined with other materials to catalyze OER . Experimental and theoretical studies demonstrate that MXenes are the efficient supporting materials for stabilizing single metal atoms . Particularly, Ti 3 C 2 T x , Ti 2 CO 2 , Ti 2 NO 2 , V 2 NO 2 , CrNO 2 , Cr 2 CO 2 , Mo 2 TiC 2 T x, Ti 3 C 2 O 2 , Ti 3 CNO 2 , and Mo 2 CO 2 , are reported as effective supporting materials for monoatomic Pd, Ti, Cu, Mo, Pt, Ni catalysts for CO 2 conversion, CO oxidation, ORR, NRR and HER.…”

“…But there are still lack of studies on MXenes supporting metal atom as OER catalysts, except that Cheng et al. predicted Ni anchored on Cr 2 CO 2 as active SAC for both OER and HER …”

MXene‐Based Nanocomposites for Energy Conversion and Storage Applications

“…Developing effective bifunctional electrocatalysts for water splitting is one of the central issues in the area of renewable energy. Zhang's team reported a bifunctional electrocatalyst prepared by anchoring the transition metal atoms on the surface of Cr 2 CO 2 MXene for water splitting (Figure b) . The results show that Ni atoms anchored on Cr 2 CO 2 (Ni/Cr 2 CO 2 ) MXene has a low overpotential of 0.16 and 0.46 V for HER and OER, respectively.…”

Recent Progress in Non‐Precious Metal Single Atomic Catalysts for Solar and Non‐Solar Driven Hydrogen Evolution Reaction

“…Other non-noble metal SAs such as Ni and Cu with mass loading of 0.29 wt% and 3.92 wt%, respectively, were also introduced into Mo 2 C. Other MXenes, such as CrCO 2 were also predicted as potential supports. [66] Novel synthetic strategies are further needed to incorporate single atoms into these supports.…”

“…Cheng et al predicted that Cr 2 CO 2 , another kind of MXene, was a promising support for SACs. [ 66 ] Their calculation results showed that Ni anchored on Cr 2 CO 2 could be quite stable and active in the catalysis of both HER and OER. Besides, in recent years, 2D transition‐metal borides (MBenes), which has similar structure with MXenes, has attracted lots of attention.…”