Interface Catalysts of In Situ-Grown TiO₂/MXenes for High-Faraday-Efficiency CO₂ Reduction

Area of Science:

• Materials Science
• Electrochemistry
• Catalysis

Background:

• Growing need for greenhouse gas remediation and clean energy sources due to climate change and energy crisis.
• Electrochemical CO2 reduction reaction (CO2RR) offers a promising route for waste CO2 utilization but is hindered by high overpotentials.
• Development of efficient electrocatalysts is crucial for advancing CO2RR technology.

Purpose of the Study:

• To fabricate and characterize a novel TiO2/MXene nanocomposite electrode for enhanced CO2RR.
• To investigate the electrochemical performance and Faradaic efficiency of the developed electrode.
• To elucidate the reaction mechanism using density functional theory (DFT) and Bader charge analysis.

Main Methods:

• Fabrication of TiO2 nanoparticles grown in situ on MXene (Ti3C2Tx) sheets via a solvothermal method.
• Electrochemical performance analysis, including cyclic voltammetry and chronoamperometry.
• Determination of Faradaic efficiency for CO2 reduction products.
• DFT calculations for mechanistic analysis and Bader charge analysis for charge distribution.

Main Results:

• The TiO2/MXene electrode exhibited excellent CO2RR characteristics.
• A high Faradaic efficiency of 99.41% for CO2 reduction was achieved at -1.9 V (vs. Ag/AgCl).
• DFT analysis revealed a mechanism involving *CO, *O, and activated CO2^2- intermediates, leading to CO and carbonate anion production.
• Bader charge analysis confirmed enhanced CO2 activation on the TiO2/MXene catalyst.

Conclusions:

• The novel TiO2/MXene nanocomposite electrode demonstrates significant potential for efficient and cost-effective CO2 conversion.
• This material offers a viable solution for greenhouse gas remediation and sustainable energy production.
• The findings pave the way for further development of advanced catalysts for CO2 utilization.