Configuration-Dependent Hollow Heterostructures for Highly Efficient Photocatalytic Hydrogen Evolution

Abstract

Photocatalytic water splitting systems based on semiconductor heterojunctions show great potential for producing hydrogen fuel from renewable resources. Extensive research has been conducted to improve heterojunctions through methods such as element doping, defect regulation, surface modification, and interface engineering. However, studies on the effects of configuration in heterostructures on photocatalytic performance are still insufficient. Herein, configuration-dependent photocatalytic performances are investigated for graphitic carbon nitride (g-C3N4) /anatase titanium dioxide (A-TiO2) hollow core-shell heterostructures. Two types of hollow core-shell heterostructures are ingeniously synthesized with different configurations namely g-C3N4/A-TiO2 and A-TiO2/g-C3N4, where g-C3N4/A-TiO2 denotes a hollow core-shell heterostructure with g-C3N4 shell and A-TiO2 core. Experimental and theoretical calculations show that g-C3N4/A-TiO2 heterostructures have broader light absorption spectra and stronger photocurrent responses compared to A-TiO2/g-C3N4. Additionally, g-C3N4/A-TiO2 features improved carrier transport efficiency and more effective electron-hole separation than A-TiO2/g-C3N4, highlighting the influence of heterostructural configuration on photocatalytic performance. Therefore, the photocatalytic hydrogen production performance of g-C3N4/A-TiO2 is 1.4 times higher than that of A-TiO2/g-C3N4. This study underscores a promising configuration-dependent strategy to design heterostructured photocatalysts for efficient photocatalysis.