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Driving Organic Nanocrystals Dissolution Through Electrochemistry |
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| Authors: | Prof Gianlorenzo Bussetti Claudia Filoni Prof Andrea Li Bassi Dr Alberto Bossi Prof Marcello Campione Prof Alessio Orbelli Biroli Prof Chiara Castiglioni Dr Silvia Trabattoni Dr Stefania De Rosa Prof Luca Tortora Prof Franco Ciccacci Prof Lamberto Duò |
| Institution: | 1. Department of Physics, Politecnico di Milano, p.za Leonardo da Vinci 32, Milano, 20133 Milano Italy;2. Department of Energy, Politecnico di Milano, via Ponzio 34/3, Milano, 20133 Milano Italy;3. Istituto di Scienze e Tecnologie Chimiche “G. Natta”, Consiglio Nazionale delle Ricerche (CNR-SCITEC), PST via G. Fantoli 16/15, 20138 Milano, Italy
SmartMatLab Center, via Golgi 19, 20133 Milano, Italy;4. Department of Earth and Environmental Sciences, Università degli Studi di Milano-Bicocca, Piazza della Scienza 4, 20126 Milano, Italy;5. Dipartimento di Chimica, Università di Pavia, via Taramelli 12, Pavia, 27100 Italy;6. Department of Chemistry, Materials and Chemical Engineering, Politecnico di Milano, p.za Leonardo da Vinci 32, 20133 Milano, Italy;7. Department of Materials Science, Università degli Studi di Milano-Bicocca, v. Roberto Cozzi 55, 20125 Milano, Italy;8. LASR3 Surface Analysis Laboratory INFN Roma Tre, Roma Tre University, via della Vasca Navale 84, 00146 Rome, Italy INFN Roma Tre, via della Vasca Navale 84, 00146 Rome, Italy;9. LASR3 Surface Analysis Laboratory INFN Roma Tre, Roma Tre University, via della Vasca Navale 84, 00146 Rome, Italy Department of Science, Roma Tre University, via della Vasca Navale 84, 00146 Rome, Italy |
| Abstract: | We have recently discussed how organic nanocrystal dissolution appears in different morphologies and the role of the solution pH in the crystal detriment process. We also highlighted the role of the local molecular chemistry in porphyrin nanocrystals having comparable structures: in water-based acid solutions, protonation of free-base porphyrin molecules is the driving force for crystal dissolution, whereas metal (ZnII) porphyrin nanocrystals remain unperturbed. However, all porphyrin types, having an electron rich π-structure, can be electrochemically oxidized. In this scenario, a key question is: does electrochemistry represent a viable strategy to drive the dissolution of both free-base and metal porphyrin nanocrystals? In this work, by exploiting electrochemical atomic force microscopy (EC-AFM), we monitor in situ and in real time the dissolution of both free-base and metal porphyrin nanocrystals, as soon as molecules reach the oxidation potential, showing different regimes according to the applied EC potential. |
| Keywords: | porphyrin porphyrin protonation etch-pit formation crystal dissolution organic nanocrystals liquid-phase atomic force microscopy electrochemistry ToF-SIMS optical spectroscopy |