A rationally designed 3DTiO2@CdZnS heterojunction photocatalyst for effectively enhanced visible-light-driven hydrogen evolution.

Abstract

Hydrogen production with higher efficiency and lower cost is of great significance for the sustainable development of energy. Zinc cadmium sulfide (CZS) is gaining more attention owing to its excellent photocatalytic properties. However, its development is greatly limited due to photogenerated charge recombination. In this work, an innovative design with a unique 3D morphology was introduced by integrating 3DTiO2 into CZS to form a novel 3DTiO2/CZS heterojunction photocatalyst. As a result, the optimized composite achieved a very high hydrogen production rate of 75.38 mmol h-1 g-1 under visible light, which is 2.4 times higher than that of the original CZS. It can also be greatly demonstrated through photoelectrochemical tests that this unique 3D morphology contributes to the effective separation of electrons and holes, thus dramatically improving the photocatalytic activity of 3DTiO2/CZS composites. The 3DTiO2/CZS composite has a rational energy band structure, which makes it more favorable for the hydrogen precipitation reaction. It is believed that such a modification strategy based on 3DTiO2 can be applied to other similar photocatalysts as well for boosting hydrogen evolution.