Highly exfoliated Ti3C2Tx MXene nanosheets atomically doped with Cu for efficient electrochemical CO2 reduction: an experimental and theoretical study. Issue 4 (7th January 2022)

• Record Type: Journal Article
• Authors: Eid, Kamel; Lu, Qingqing; Abdel-Azeim, Safwat; Soliman, Ahmed; Abdullah, Aboubakr M.; Abdelgwad, Ahmed M.; Forbes, Roy P.; Ozoemena, Kenneth I.; Varma, Rajender S.; Shibl, Mohamed F.
• Is Part Of: Journal of materials chemistry. Volume 10:Issue 4(2022)
• Page Start: 1965
• Page End: 1975
• Publication Date: 2022-01-07
• Subjects: Materials -- Research -- Periodicals; Chemistry, Analytic -- Periodicals; Environmental sciences -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d1ta09471h
• Languages: English
• ISSNs: 2050-7488

Abstract

Abstract : We present a facile method for the rational design of highly exfoliated two-dimensional Ti3 C2 T x nanosheets (T x = O, OH, and F) doped with Cu (Cu/Ti3 C2 T x ) for electrochemical CO2 reduction to formic acid at low Cu content of ∼1 wt%. Abstract : Ti3 C2 T x MXene nanostructures have garnered attention for various catalytic applications due to their built-in electronic properties. Herein, we rationally design highly exfoliated two-dimensional Ti3 C2 T x nanosheets (T x = O, OH, and F) doped with Cu (denoted as Cu/Ti3 C2 T x ) for the electrochemical CO2 reduction reaction (CO2 RR). The fabrication process entails the selective chemical etching of Ti3 AlC2 followed by the delamination thereof under ultrasonic treatment and subsequent mixing with a Cu precursor to allow in situ doping. The resultant Cu/Ti3 C2 T x are highly exfoliated nanosheets with a surface area of 46 m 2 g −1 and are uniformly doped with Cu atoms (1.04 wt%). The CO2 RR current density of Cu/Ti3 C2 T x (−1.08 mA cm −2 ) was 3.6 times higher than that of Ti3 C2 T x (−0.3 mA cm −2 ) besides a lower onset reduction potential and Tafel slope, and higher stability, due to the greater surface area, electronic effect, and quicker charge transfer on Cu/Ti3 C2 T x . The formic acid (HCOOH) faradaic efficiency on Cu/Ti3 C2 T x (58.1%) was 3-fold higher than that on Ti3 C2 T x (18.7%). Based on density functional theory (DFT) simulation, Cu-doping induces polarized sites with high electron density, allowing the CO2 RR path through the *HCOOH intermediate to form formic acid (HCOOH). The study presented here will open new pathways for using Ti3 C2 T x doped with various metals for the CO2 RR.