A double transition metal MXene/S-scheme heterojunction composite with improved photoelectrochemical and photocatalytic properties

Herein, a novel double transition metal MXene (DTMXene) S-scheme photocatalyst was constructed with potential application in mineralization of organic pollutants found in water. The fabrication of the DTMXene heterojunction photocatalyst (Ce₂S₃/WO₃@TiVCT_x) was achieved through an ultrasonication and calcination approach. The highly conductive DTMXene (TiVC), was incorporated into an S-scheme heterojunction to maximize the separation of the charge kinetics, subsequently enhancing the photocatalytic properties. The phase structure, morphology, photoelectrochemical, and optical properties of the synthesized materials were characterized and confirmed by spectroscopic, microscopic, and photoelectrochemical techniques. The DTMXene-based heterojunction photocatalyst showed a significant increase in optical and electrochemical properties compared to the pristine materials of the 7 wt%-Ce₂S₃/WO₃@TiVC-7 wt% ternary composite exhibiting excellent photoelectrochemical properties, including a weak PL emission intensity and a decreased EIS resistance, indicating efficient separation and transfer of photogenerated charge carriers. A significant improvement of the photocatalytic and electrochemical properties is attributed to the excellent conductive nature of the DTMXene, which facilitates the separation of the photogenerated charge carriers. This work therefore gives a novel approach to the fabrication of a reliable DTMXene-based photocatalyst with enhanced potential in environmental remediation, hydrogen evolution, and energy storage.