Plasmonic nanosystems built by metal/semiconductor hybrid nanoparticles had shown promising applications enabling an efficient solar light harvesting and enhancing the photocatalytic activity. Core-shell systems as Au-TiO2nanoparticles are ideal candidates due to the dynamic synergy established at the interface able to improve the e-/h+pairs separation and stability. Recently, anisotropic AuNPs gain increasing interests thanks to their tunable localized surface plasmon resonance band (LSPR) in the visible range.1However, reliable protocols to synthesize anisotropic AuNPs covered with TiO2by direct wet chemistry approaches is still challenging.2Herein, we report a novel synthetic protocol for the preparation of star-shaped AuNPs (AuNS) functionalized with nanostructured thin TiO2layers, by exploiting a designed bench-top microfluidic reactor.3This one-pot seedless procedure is based on the accurate mixture of gold and titania precursors that allows the direct and continuous production of AuNS@TiO2without adding any stabilizer agent. The hybrid composites exhibit a stable red-shift LSPR band and a good dispersibility in water and alcohols. Au/TiO2nanosystems show under simulated solar light a catalytic photoactivity toward the Rhodamine-B degradation. Before the photocatalytic tests, any eventual residual ligand on the NP surface has been cleaned-off by treating NPs with H2O2, affording purified hybrid nanosystems highly active and water dispersible.AuNS@TiO2were fully characterized by UV/vis, ICP-OES, HRTEM, STEM, EELS map to disclose the Ti distribution. This innovative procedure is reproducible and scalable, allowing the production of a high amount of shape-controlled AuNS@TiO2hybrid nanoparticles, dispersed in solution and easy to concentrate in small volumes.1. N. Li, P. Zhao, D. Astruc Angew. Chemie, Int. Ed.2014, 53, 1756.2. B. Wu, D. Liu, S. Mubeen, T. T. Chuong, M. Moskovits, G. D. Stucky JACS2016, 138(4) 1114.3. A. Silvestri, L. Lay, R. Psaro, L. Polito, C. Evangelisti Chem. Eur. J.2017, 23, 9732.
In-flow Synthesis of Multibranched Au/TiO2 Hybrid Nanosystem:Exploiting the Plasmonic Features for Catalytic Purposes
Marcello Marelli;Filippo Bossola;Vladimiro Dal Santo;Rinaldo Psaro;Laura Polito
2019
Abstract
Plasmonic nanosystems built by metal/semiconductor hybrid nanoparticles had shown promising applications enabling an efficient solar light harvesting and enhancing the photocatalytic activity. Core-shell systems as Au-TiO2nanoparticles are ideal candidates due to the dynamic synergy established at the interface able to improve the e-/h+pairs separation and stability. Recently, anisotropic AuNPs gain increasing interests thanks to their tunable localized surface plasmon resonance band (LSPR) in the visible range.1However, reliable protocols to synthesize anisotropic AuNPs covered with TiO2by direct wet chemistry approaches is still challenging.2Herein, we report a novel synthetic protocol for the preparation of star-shaped AuNPs (AuNS) functionalized with nanostructured thin TiO2layers, by exploiting a designed bench-top microfluidic reactor.3This one-pot seedless procedure is based on the accurate mixture of gold and titania precursors that allows the direct and continuous production of AuNS@TiO2without adding any stabilizer agent. The hybrid composites exhibit a stable red-shift LSPR band and a good dispersibility in water and alcohols. Au/TiO2nanosystems show under simulated solar light a catalytic photoactivity toward the Rhodamine-B degradation. Before the photocatalytic tests, any eventual residual ligand on the NP surface has been cleaned-off by treating NPs with H2O2, affording purified hybrid nanosystems highly active and water dispersible.AuNS@TiO2were fully characterized by UV/vis, ICP-OES, HRTEM, STEM, EELS map to disclose the Ti distribution. This innovative procedure is reproducible and scalable, allowing the production of a high amount of shape-controlled AuNS@TiO2hybrid nanoparticles, dispersed in solution and easy to concentrate in small volumes.1. N. Li, P. Zhao, D. Astruc Angew. Chemie, Int. Ed.2014, 53, 1756.2. B. Wu, D. Liu, S. Mubeen, T. T. Chuong, M. Moskovits, G. D. Stucky JACS2016, 138(4) 1114.3. A. Silvestri, L. Lay, R. Psaro, L. Polito, C. Evangelisti Chem. Eur. J.2017, 23, 9732.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
