Tunable Electron-Hole Distribution in π-Conjugated Porous Organic Polymers for Unified Light-Driven Au(III)...

The development of materials that integrate fluorescence sensing with light-promoted adsorption is essential for the selective detection and efficient recovery of gold. However, most previously reported materials address either detection or recovery alone, thereby restricting their potential application as multifunctional probes, photocatalysts, or adsorbents. Herein, we introduce two multifunctional porous organic polymers (POPs), TBE-S-POP and TBE-O-POP, that combine detection and recovery functions in a single platform. Both materials feature a π-conjugated 1,1,2,2-tetra(biphenyl-4-yl)ethene core, while differ in their electron-accepting units, dithiobiurea in TBE-S-POP and biurea in TBE-O-POP. By strategically modulating their electron-hole distribution, we achieved complementary functions within a single platform. TBE-S-POP, featuring a more separated electron-hole distribution, exhibits superior photocatalytic activity and achieves a remarkable gold adsorption capacity of 2267.7 mg g^{- 1} under light irradiation. In contrast, TBE-O-POP, which exhibits a more overlapped charge distribution, displays stronger fluorescence and provides a reliable response to Au^{3 +} in the 0-50 µM range. Density functional theory calculations elucidate the underlying mechanism of their divergent photophysical behaviors. This work pioneers a design strategy by modulating electron-hole separation to unify detection, photoreduction, and adsorption in a single POP platform, offering a novel insight into the construction of advanced materials for gold sensing and recovery.