Rational engineering of morphology modulated Ti-ZnO thin films coupled monolayer Ti3C2 MXene for efficient visible light PEC water splitting activity

Abstract

• Morphology modulated Ti 3 C 2 /Ti-ZnO composite constructed. • Well-dispersed grain-like morphology of Ti-ZnO anchored on monolayer Ti 3 C 2 MXene. • Ti 3 C 2 /Ti-ZnO composite show improved visible light PEC activity. • Ti 3 C 2 /Ti-ZnO composite promote the long-term PEC activity for 21 min. • The charge transport mechanism under visible light PEC activity is evaluated. Novel morphology modulated monolayer 2D Ti 3 C 2 MXene coupled Ti-doped ZnO (Ti 3 C 2 /Ti-ZnO) photoelectrode developed for exploring interfacial charge transfer and visible-light photoelectrochemical (PEC) water splitting. Here, we altered the flake-like ZnO into grain-like morphology by selective Ti (2 at.%) doping into ZnO under simultaneous radio frequency (RF) and direct-current (DC) magnetron sputtering. This study describes the versatility of the Ti 3 C 2 /Ti-ZnO (monolayer/grain-like) interface. Transmission electron microscopy findings suggest that Ti 3 C 2 MXene developed in a monolayer. Moreover, scanning electron microscopy proved a consistent grain-like Ti-ZnO thin film interface with monolayer Ti 3 C 2 MXene. We also find Hall effect measurements to uncover the interfacial impact on charge carrier generation. The fabricated monolayer/grain-like interface modulated the band gap towards visible region. With all the above benefits, Ti 3 C 2 /Ti-ZnO achieved stable visible water splitting for 21 min. Overall, these findings provide the potentiality of Ti 3 C 2 /Ti-ZnO photoelectrode to extend the PEC activity towards the visible region.