Enhanced photoactivity and conductivity in transparent TiO 2 nanocrystals/graphene hybrid anodes

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Materials for energy and sustainability, 2017, Vol.5 (19), p.9307-9315
• Main Authors: Ingrosso, C., Bianco, G. V., Pifferi, V., Guffanti, P., Petronella, F., Comparelli, R., Agostiano, A., Striccoli, M., Palchetti, I., Falciola, L., Curri, M. L., Bruno, G.
• Format: Article
• Language: English
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/C7TA01425B

An optically transparent and UV-light active anode, characterized by high (photo)conductivity, charge mobility and exciton lifetime, based on graphene, grown by CVD, decorated with colloidal TiO 2 nanocrystals (NCs), has been fabricated, by a direct and facile solution-based procedure. TiO 2 NCs anchor onto graphene by means of π–π stacking interactions occurring between the pyrene-1-butyric acid (PBA) surface coating ligand and the 2-D platform and assemble in a highly interconnected multilayered layout, by means of interligand π–π forces, retaining composition and geometry, along with the graphene structure. Remarkably, the PBA-coated TiO 2 NCs on the graphene increase its electrical conductivity, electroactivity, and capacitive behavior, as well as photoelectrical response under UV-light, resulting in a 50% enhanced photoelectroactivity and a long exciton recombination lifetime. The photoanodes can be integrated into solar cells as optically transparent electrodes, in photodetectors, FETs and (bio)sensors.