Covalently assembled photocatalytic system
253× faster electron transfer
Covalent linkage between photosensitizer and polyoxometalate switches the quenching mechanism and boosts electron transfer, enabling efficient H2 evolution and tandem hydrogenation under visible light.
Xu, Yue · Wang, Ping · Guo, Song · Yao, Shuang · Wang, Cheng · Zhang, Zhiming
Angewandte Chemie - International Edition 2025
Specifications
- Turnover number for H2 evolution
- {'zh': '2280', 'en': '2280'}
- Electron quenching rate constant
- {'zh': '5.87 × 10^11', 'en': '5.87 × 10^11'} M^-1 s^-1
- Ethylbenzene yield in tandem styrene hydrogenation
- {'zh': '99.9', 'en': '99.9'} %
Advantages
Over two orders faster electron transfer
Covalent linkage increases the electron quenching rate constant from 2.54×10^9 M^-1 s^-1 in the physical mixture to 5.87×10^11 M^-1 s^-1, demonstrating enhanced electron transfer from photosensitizer to catalyst.
Turnover number of 2280
The covalent assembly exhibits a turnover number of 2280 for H2 evolution, ~18 times higher than the physical mixture, indicating greatly improved catalytic cycling efficiency.
99.9% yield in tandem hydrogenation
The generated H2 can drive tandem styrene hydrogenation under ambient conditions, achieving 99.9% ethylbenzene yield, enabling integration of photocatalytic H2 production with organic synthesis.
Applications
- Photocatalytic H2 production：Provide efficient visible-light H2 evolution catalyst, reducing precious metal usage and improving conversion efficiency.
- Photocatalytic organic synthesis：Can be directly used in photocatalytic hydrogenation to obtain high-purity products at ambient conditions.
- Tandem hydrogenation：Enable tandem H2 production and hydrogenation, avoiding H2 separation and storage, reducing energy consumption.
- Polyoxometalate：Exploit polyoxometalate's modifiability and redox properties to construct efficient photocatalytic assemblies.
- Photosensitizer-catalyst assembly：Offer a covalent linkage strategy to build stable and efficient photosensitizer-catalyst composite systems.