CdS QDs decorated on 3D flower-like Sn3O4: a hierarchical photocatalyst with boosted charge separation for hydrogen production

Abstract

Developing novel catalysts with excellent photocatalytic hydrogen evolution activity is crucial for expediting current research on solar-chemical energy conversion. In the present study, unique Sn₃O₄/CdS composites were carefully designed and prepared using a facile hydrothermal method to achieve outstanding photocatalytic H₂ production activity. Various techniques were employed to determine the crystalline structure, chemical composition, microstructure, and optical and electrochemical characteristics of the prepared samples. The experimental results indicate that zero-dimensional (0D) CdS quantum dots were tightly attached to the surface of three-dimensional (3D) Sn₃O₄ nanoflowers. Furthermore, enhanced light-absorbing capacity and accelerated electron–hole separation and transfer were achieved after incorporating CdS quantum dots into Sn₃O₄ nanoflowers. The generation rate of hydrogen using the optimal sample (Sn₃O₄/CdS QDs-2) was about 20.74 μmol g⁻¹ h⁻¹, which was 2.86 and 3.16 times those of pure Sn₃O₄ and CdS, respectively. In addition, the possible photocatalytic H₂ production mechanism of Sn₃O₄/CdS nanocomposites was also revealed. This work is highly desirable to provide valuable inspiration for rational design and preparation of efficient photocatalysts for H₂ evolution.