A new composite photocatalyst of SiO₂@C₃N₄–CdS QDs was designed and synthesized, delivering enhanced hydrogen evolution performance. Under visible light irradiation, the hydrogen evolution rate of the photocatalyst is 225.1 μmol/g/h, which is about 80 times that of pure g-C₃N₄ and 2.1 times that of CdS. In this system, the g-C₃N₄ thin film was uniformly and compactly coated on the surface of the nanosphere with SiO₂ as supporting template, which shortened the distance from the electron to the surface and accelerated the charge carrier transfer. Furthermore, the heterojunction formed by g-C₃N₄ and CdS QDs has a more suitable energy band structure and recover the scattered light near field of SiO₂ nanospheres, which significantly enhances the light-trapping ability and the separation efficiency between electrons and holes. Consequently, the synergistic effect of SiO₂, g-C₃N₄ and CdS QDs visibly improves the hydrogen evolution performance of photocatalyst.

设计并合成了一种新型的 SiO ₂ @C ₃ N ₄ –CdS QD复合光催化剂，可提高析氢性能。在可见光照射下，光催化剂的析氢速率为225.1 μmol/g/h，约为纯gC ₃ N _{4 的}80倍和CdS的2.1倍。在该体系中，gC ₃ N ₄薄膜以SiO ₂为支撑模板均匀致密地包覆在纳米球表面，缩短了电子到表面的距离，加速了电荷载流子的转移。此外，gC ₃ N ₄形成的异质结CdS QDs具有更合适的能带结构，回收SiO ₂纳米球近场的散射光，显着增强了光捕获能力和电子与空穴的分离效率。因此，SiO ₂、gC ₃ N ₄和CdS QDs的协同作用明显提高了光催化剂的析氢性能。