MXene-derived Ti3C2–TiO2/BiOCl heterojunctions with enhanced visible-light photocatalysis and electrochemical activity

Abstract

Environmental pollution, particularly from persistent organic contaminants like phenol, and increasing demand for efficient energy storage materials are urgent global challenges. To address these challenges, Ti₃C₂–TiO₂/BiOCl heterojunction was engineered for photocatalytic degradation and energy storage. The combination of Ti₃C₂–TiO₂. and BiOCl enhanced charge separation capacity and increased absorption in the visible region, which is evidenced by XRD, SEM, and UV-vis with a narrowing in the bandgap (2.82 eV to 3.01 eV). DFT analysis confirmed the metallic conductivity in Ti₃C₂/TiO₂ while incorporation of BiOCl induced interfacial narrowing of the bandgap by ∼0.23 eV, introducing semiconducting behavior. Raman analysis confirmed robust interfacial coupling with distinct peaks exhibiting improved structural integrity, and PL spectra demonstrated significant suppression of the charge carrier recombination rate with optimal charge carrier dynamics. Surface chemical states and interfacial band electronic interactions in the heterojunction system are supported by XPS. The 4 wt% Ti₃C₂–TiO₂/BiOCl exhibited photocatalytic degradation with 96% phenol under visible-light irradiation due to optimal electron–hole separation. Electrochemical studies confirmed a high specific capacity of 609 C g⁻¹ with current density at 1 mV s⁻¹ with robust cycles promoting exceptional energy storage capability. The outcomes emphasize the potential of Ti₃C₂–TiO₂/BiOCl as a promising material for environmental remediation and high-efficiency energy storage.