Photocatalytic hydrogen production coupled with selective oxidation of organic substrates to produce high-value-added fine chemicals has drawn increasing attention. Herein, we report a noble metal-free photocatalyst for the highly efficient and simultaneous generation of hydrogen and the selective oxidation of benzyl alcohol into benzaldehyde over CdS@MoS₂ heterostructures under visible light. Without the need for a sacrificial agent, CdS@MoS₂ displayed an excellent hydrogen production rate of 4233 µmol g⁻¹ h⁻¹ with 0.3 mmol benzyl alcohol, which is approximately 53 times higher than that of bare CdS nanorods (80 µmol g⁻¹ h⁻¹). The reaction system was highly selective for the oxidation of benzyl alcohol into benzaldehyde. When the amount of benzyl alcohol increased to 1.0 mmol, the hydrogen production reached 9033 µmol g⁻¹ h⁻¹. Scanning electron microscopy and transmission electron microscopy images revealed that p-type MoS₂ sheets with a flower-like structure closely adhered to n-type semiconductor CdS nanorods through the formation of a p-n heterojunction. As a potential Z-scheme photocatalyst, the CdS@MoS₂ heterostructure effectively produces and separates electron-hole pairs under visible light. Thus, the electrons are used for reduction to generate hydrogen, and the holes oxidize benzyl alcohol into benzaldehyde. Moreover, a mechanism of photogenerated charge transfer and separation was proposed and verified by photoluminescence, electrochemical impedance spectroscopy, photocurrent and Mott-Schottky measurements. The results reveal that the CdS@MoS₂ heterojunctions have rapid and efficient charge separation and transfer, thereby greatly improving benzyl alcohol dehydrogenation. This work provides insight into the rational design of high-performance Z-scheme photocatalysts and the use of holes and electrons to obtain two valuable chemicals simultaneously.

光催化制氢与有机底物的选择性氧化以产生高附加值的精细化学品的结合已引起越来越多的关注。在此，我们报道了一种无贵金属的光催化剂，用于在可见光下通过CdS @ MoS ₂异质结构高效高效地同时产生氢气和将苄醇选择性氧化成苯甲醛。而不需要牺牲剂，硫化镉@的MoS ₂显示的4233优异的产氢速率微摩尔克^-1 ħ ^-1用0.3毫摩尔的苄醇，其比裸的CdS纳米棒的高约53倍（80微摩尔克^{- 1}小时^-1）。该反应体系对于将苄醇氧化为苯甲醛具有高度选择性。当苯甲醇的量增加到1.0mmol时，氢产生达到9033μmolg ^-1 h ^-1。扫描电子显微镜和透射电子显微镜图像显示，具有花状结构的p型MoS ₂片通过形成pn异质结紧密粘附于n型半导体CdS纳米棒。作为潜在的Z方案光催化剂，CdS @ MoS ₂异质结构在可见光下有效地产生和分离电子-空穴对。因此，电子用于还原以产生氢，并且空穴将苄醇氧化为苯甲醛。此外，提出了一种光生电荷转移和分离的机理，并通过光致发光，电化学阻抗谱，光电流和莫特-肖特基测量进行了验证。结果表明，CdS @ MoS ₂异质结具有快速有效的电荷分离和转移作用，从而大大改善了苯甲醇的脱氢反应。这项工作为高性能Z型光催化剂的合理设计以及使用空穴和电子同时获得两种有价值的化学物质提供了见识。