The CoNi@C/Mo1.33C i‐MXene Derived from Novel (Mo2/3R1/3)2GaC (R = Dy, Ho, Er, Tm, and Lu) Nanolaminations for Electrochemical Application in Electrocatalytic Hydrogen Evolution and Supercapacitance
Year: 2024
Type: article
Abstract: 2D Mo1.33C i‐MXene is highly promising for electrochemical applications. Here, a synthetic strategy is reported, enabling the uniform distribution of carbon‐coated CoNi (CoNi@C) nanoparticles on the vacancy‐ordered Mo1.33C i‐MXene nanosheets, thereby fully exposing the active sites of CoNi@C. First, five novel Ga‐containing (Mo2/3R1/3)2GaC (R = Dy, Ho, Er, Tm, and Lu) i‐MAX phases are synthesized as the precursor and found to be crystallized into Cmcm structure, followed by hydrothermal etching and delamination. Subsequently, CoNi– MOF is in situ grown on derived Mo1.33C i‐MXene nanosheets. By modifying the loading mass and annealing condition, CoNi–MOF is transformed into the CoNi@C and the CoNi@C/Mo1.33C displayed outstanding hydrogen evolution reaction activity with low overpotential (73 mV at 10 mA cm−2) and small Tafel slope (84 mV dec−1). Moreover, the gravimetric capacitance is also increased from 68 F g−1 in CoNi@C to 575.1 F g−1 in CoNi@C/Mo1.33C‐50 at 0.5 A g−1. After ≈5000 cycles, activation is complete, and the specific capacitance reaches its maximum value. Additionally, the specific capacitance remains stable at 95% after additional 10 000 cycles. This work improves the catalytic and supercapacitor performance of composite nanomaterials by optimizing the distribution of active sites on Mo1.33C i‐MXene, and also extends the application of Mo1.33C i‐MXene.
Source: Small
Authors: Zhaohui Chen, Yunxiang Liao, He Chong, Hongyun Guo, Qiang Li, Weibin Cui
Institution: Northeastern University
Language: English
Field: Energy
Domain: Physical Sciences
Open Access status: bronze
OpenAlex ID: W4405545397