Solar energy harvesting and conversion into useful chemical energy with the aid of semiconductor photocatalysts is a promising technique to solve both energy and environmental issues. This work reports a successful synthesis of CdSe quantum dots (QDs) modified phosphorus doped g-C₃N₄ (P-CN) for advanced photocatalytic applications. Phosphorus doping and structural coupling with CdSe QDs are shown to significantly extend visible-light response of g-C₃N₄ up to 700 nm. The optimized sample 4CdSe/P-CN demonstrates enhanced visible-light driven overall water splitting activities for H₂ and O₂ evolution i.e. 113 and 55.5 µmol.h⁻¹. g⁻¹, respectively, as well as very high photocatalytic CO₂ to CH₄ conversion efficiency (47 µmol.h⁻¹. g⁻¹). It also exhibit higher activity (78 %) for 2,4-dichlorophenol degradation as compared to pristine CN-sample. Combined photoluminescence, transient/single wavelength photocurrent, photoelectrochemical, and coumarin fluorescence spectroscopy demonstrate that 4CdSe/P-CN nanocomposite exhibit enhanced charge separation efficiency which is responsible for improved visible light catalytic activities. Our work thus provide a new strategy to design low-cost and sustainable photocatalysis with wide visible-light activity for practical overall water splitting and CO₂ reduction applications.

借助半导体光催化剂收集太阳能并将其转化为有用的化学能是解决能源和环境问题的有前途的技术。这项工作报告成功地合成了CdSe量子点（QDs）修饰的磷掺杂的gC ₃ N ₄（P-CN），用于高级光催化应用。磷掺杂和与CdSe量子点的结构耦合显示可将gC ₃ N _4的可见光响应显着扩展至700 nm。优化的样品4CdSe / P-CN显示出增强的可见光驱动的H ₂和O ₂逸出的总水分解活性，即113和55.5 µmol.h ^-1。g ^-1分别，以及非常高的光催化CO ₂至CH ₄的转换效率（47μmol.h ^-1。克^-1）。与原始CN样品相比，它对2,4-二氯苯酚的降解还具有较高的活性（78％）。结合的光致发光，瞬态/单波长光电流，光电化学和香豆素荧光光谱表明，4CdSe / P-CN纳米复合材料显示出增强的电荷分离效率，这有助于改善可见光催化活性。因此，我们的工作提供了一种新的策略，以设计低成本，可持续的，具有广泛可见光活性的光催化，以用于实际的整体水分解和CO ₂还原应用。