Bifunctional Photochemical Performance Based on Pt-TiO₂ Hollow Sphere Schottky Junction: From Photocatalytic Hydrogen...

The Schottky junction at the metal-semiconductor interface is a pivotal structure for modulating charge carrier dynamics in photochemical applications. In this work, a Schottky barrier was constructed in Pt nanoparticle-modified TiO₂ hollow spheres (Pt-TiO₂ HSs), leading to bifunctional performance enhancement. The optimized sample with 0.75 wt % Pt not only achieved excellent utilization of the photogenerated electrons with a high photocatalytic hydrogen evolution rate of 16,295.8 μmol·g^-1·h^-1 but also exhibited remarkable sensitivity (24.71 μA·mM^-1·cm^-1) and a low detection limit (0.97 μM) for photoelectrochemical (PEC) glucose sensing. Through a combination of structural characterizations, PEC analyses, and theoretical simulations, it was deduced that the Pt-induced Schottky effect is the central mechanism responsible for the enhanced performance in both energy conversion and sensing applications. The effective built-in electric field formed by high-work-function Pt promotes directional separation and transport of interfacial charges in Pt-TiO₂. Furthermore, the photochemical mechanisms in the two systems were elucidated. This study not only demonstrates the common mechanism of the same interface engineering strategy in different photochemical applications but also provides new insights for designing multifunctional photochemical materials.