Rational Design of Mxenes with Atomically Doped Multimetals for Efficient Electrochemical and Photoelecrochemical Conversion of Co2 to Usable Hydrocarbons

Abstract

Ti3C2Tx MXene is a promising catalyst for several applications; however, its electrochemical conversion of CO2 to useable hydrocarbons has been rarely reported experimentally. Herein, two-dimensional Ti3C2Tx nanosheets doped at an atomic level with Pd-M/Ti3C2Tx (M: Cu and Co) were synthesized by etching off the Al atom in Ti3AlC2 followed by intercalation and exfoliation. Thereafter, Pd-Cu and Pd-Co were doped in Ti3C2Tx nanosheets. The fabrication method is based on creating Tx group upon etching along with highly active Ti vacancies that are ideal sites for anchoring and stabilizing the doped metal atoms. The electrochemical CO2RR (CO2 reduction reaction) for the fabricated sample Pd-Cu/Ti3C2Tx and Pd-Co/Ti3C2Tx resulted in converting CO2 into ?-Glucose and formate (HCOO- ), respectively. The CO2RR current density of Pd-Cu/Ti3C2Tx (0.66 mAcm-2 ) was the highest compared to the rest of the doped samples and more than 3 times that of pristine MXene Ti3C2Tx (0.18 mAcm-2 ). The as-synthesized Pd-M/Ti3C2Tx combine between the unique catalytic merits of two dopants and quick charge transfer and electron density of Ti3C2Tx. This study may pave perspectives on the development of MXenes for CO2RR to valuable fuels.