resumo
Heptazine-based polymeric carbon nitrides (PCN) are promising photocatalysts for light-driven redox transformations. However, their activity is hampered by low surface area resulting in low concentration of accessible active sites. Herein, we report a bottom-up preparation of PCN nanoparticles with a narrow size distribution (ca. 10 +/- 3 nm), which are fully soluble in water showing no gelation or precipitation over several months. They allow photocatalysis to be carried out under quasi-homogeneous conditions. The superior performance of water-soluble PCN, compared to conventional solid PCN, is shown in photocatalytic H2O2 production via reduction of oxygen accompanied by highly selective photooxidation of 4-methoxybenzyl alcohol and benzyl alcohol or lignocellulose-derived feedstock (ethanol, glycerol, glucose). The dissolved photocatalyst can be easily recovered and re-dissolved by simple modulation of the ionic strength of the medium, without any loss of activity and selectivity.
palavras-chave
POLY(HEPTAZINE IMIDES); HYDROGEN-PEROXIDE; CYAMELURIC ACID; QUANTUM YIELD; OXIDATION; NANOSHEETS; DOTS; PHOTOOXIDATION; DISSOLUTION; ACTIVATION
categoria
Chemistry
autores
Krivtsov, I; Mitoraj, D; Adler, C; Ilkaeva, M; Sardo, M; Mafra, L; Neumann, C; Turchanin, A; Li, CY; Dietzek, B; Leiter, R; Biskupek, J; Kaiser, U; Im, C; Kirchhoff, B; Jacob, T; Beranek, R
nossos autores
Luís Mafra
Investigador Principal
Marina Ilkaeva
Investigador JúniorProjectos
CICECO - Aveiro Institute of Materials (UID/CTM/50011/2019)
agradecimentos
This work was funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation)-Projektnummer 364549901-TRR 234 [Projects B6, B7, C3 and Z2] and BE 5102/3-1. We acknowledge also support by Spanish MINECO (MAT2016-78155-C2-1-R) and Gobierno del Principado de Asturias (GRUPIN-ID2018-170), and the project CICECO-Aveiro Institute of Materials, FCT Ref. UID/CTM/50011/2019, financed by national funds through the FCT/MCTES. L.M., M.S., and M.I. also acknowledge the National NMR Network (PTNMR), partially supported by Infrastructure Project No 022161, and FCT/MCTES for funding (Project PTDC/QEQ-QAN/6373/2014). B.K. acknowledges the University of Iceland Research Fund for support through a PhD fellowship. Computational resources were provided by the state of Baden-Wurttemberg through bwHPC and the German Science Foundation (DFG) under Grant No. INST 40/467-1 FUGG. C.N. and A.T. acknowledge financial support of the DFG through the project TU 149/8-2 Towards photo-active membranes for artificial photosynthesis as well as the DFG through a research infrastructure grant INST 275/257-1 FUGG. I.K. acknowledges the support of the Alexander von Humboldt Foundation through the Humboldt Research Fellowship.