Steering charge kinetics in W2C@C/TiO2 heterojunction architecture: Efficient solar-light-driven hydrogen generation

The constructing of functional materials with well-defined nanostructure , showing efficient charge separation and transportation properties, has been intensively and in depth investigated to fabricate catalysts for H 2 generation from solar-driven water reduction. Here we demonstrate that loading W 2 C@C structure in which each W 2 C nanoparticle (NP) is wrapped by carbon shell on surface of hollow TiO 2 microspheres (HTMs) can enhance the separation of photogenerated electron-hole pairs by building an internal electric field in W 2 C@C/HTMs composite structure and act as the reaction active sites for water reduction. As expected, the optimized W 2 C@C/HTMs construction exhibits the highest photocatalytic H 2 generation rate of 6.91 mmol h −1 g −1 under simulated solar light illumination, over 20 times larger than that of bare HTMs. The underlying mechanism has been investigated from the perspective of photochemistry and photophysics based on a series of characterization techniques, which suggests that W 2 C@C can effectively steer the charge kinetics, maximizing the charge carriers’ separation.