Insight into the design of a Ti3C2 MXene/Ti4O7 composite ceramic membrane boosts the electrocatalytic activity for 1,4-dioxane electro-oxidation

Abstract

Efficient refractory organic compound (ROC) removal through Ti4O7 ceramic membrane in electrochemical advanced oxidation processes (EAOPs) requires high electrochemical reactivity and stability. Herein, we report on the synthesis and properties of Ti3C2 MXene-doped Ti4O7 ceramic membranes (Ti3C2@Ti4O7) using a spark plasma sintering system, after employing density functional theory calculations to design the electrocatalyst. Doping with Ti3C2 MXene resulted in interfacial Ti–O–Ti chemical bond formation, which greatly improved the electronic structure and the generation of hydroxyl radicals (•OH). Compared with pristine Ti4O7, the charge-transfer resistance of Ti3C2@Ti4O7 decreased from 59.09 to 4.21 Ω, and the •OH generation rate enhanced 2.3 − 2.6-fold. Ti3C2@Ti4O7 could effectively remove 1,4-Dioxane from natural groundwater, and the residual 1,4-Dioxane concentration met the requirements for drinking water. Our study provides a proof-of-concept demonstration using Ti3C2 MXene to manufacture a doped Ti4O7 ceramic membrane for effective ROC removal. The theoretical predictions from this study can inspire novel electrocatalyst designs for EAOPs.