Co-assembly strategy for organic/inorganic heterojunctions with intimate interfaces and effective charges separation

Heterojunctions, especially for organic/inorganic heterojunctions (OIHJ) have been demonstrated as a robust tool to extend solar spectrum response and accelerate the separation of photoinduced chargers. However, efficient preparation of controllable OIHJ with fascinating interfacial properties still remain a challenging target. In this regard, we develop nanoscale OIHJ by a general coassembly strategy, including core/shell and hollow sandwich-type junction. Amphiphilic molecule with one polyethylene glycol arm (TBT600) and linear conjugated polymers (PFTBT) containing 9,9'-spiro-bifluorene and bis(3,4-dimethoxythiophen-2-yl)benzothiadiazole were designed. Diversified interactions and planarized stacking mode between PFTBT and TBT600 stabilized the hollow sandwich-type structure upon sonication cavitation and allows intimate PFTBT-TiO(2 i)nterfaces. Experimental results indicated that the sandwich-type heterojunctions exhibited more effective charges separation efficiency than core/shell heterojunctions. The enhanced photo-current activity could be ascribed to its unique features, including: (i) twofold intimate PFTBT-TiO2 interfaces and Z-scheme junction accelerate the charge separation/transfer amongst the nanoscale shells; (ii) hollow structure also benefits increasing photon absorption efficacy. This study provide a facile tool to prepare semiconductor heterojunctions by co-assembly strategy and reveals the advantages of hollow sandwich-type heterojunctions on exciton dissociation and photon absorption. We hope such a co-assembly strategy will provide an alternative toolbox to design functional nanomaterials for photo-electric and catalytic devices.