Boosting alcohol production via nitrogen-doped electrochemically exfoliated graphene and layered Ti3CN MXene hybrid photo-electrocatalyst

In the pursuit of efficient ambient methane (CH4) conversion, we introduce a novel MXene combining with a nitrogen-doped graphene (MX@NG) hybrid as a photoelectrocatalyst for CH4 oxidation under ambient conditions with light and external bias. Through electrostatic assembly, graphene nanosheets are incorporated between MXene sheets, effectively preventing MXene nanosheet restacking and increasing interlayer spacing. This enhances ion diffusion of electrolyte, increasing access to electroactive sites. Using Ti3CN as MXene and nitrogen-doped graphene (NG) as catalyst supports, our research demonstrates the superior performance of the MX@NG composite over pure NG and MXene for methane oxidation. After a 4-hour reaction with a 2 × 2 cm2, 10 mg sample-loaded carbon paper, it produces 17 µmol/ml of CH3OH and 14.5 µmol/ml of HCOOH at 0.8 V vs. Ag/AgCl. This enhanced performance results from the synergy between MXene and graphene, improving charge transfer and promoting efficient utilization of photoexcited charges. Additionally, excellent electrical conductivity of NG facilitates the transfer of photo-generated electrons to surface reaction sites, promoting free radical formation. The incorporation of MXene extends visible light absorption and improves charge separation, thereby enhancing solar energy utilization. Overall, this study highlights the potential of MX@NG composite in solar light-based electrocatalytic methane oxidation.