abstract
Nanostructured thin films are widely investigated for application in multifunctional devices thanks to their peculiar optoelectronic properties. In this work anatase TiO2 nanoparticles (average diameter 10 nm) synthesised by a green aqueous sol-gel route are exploited to fabricate optically active electrodes for pseudocapacitive-electrochromic devices. In our approach, highly transparent and homogeneous thin films having a good electronic coupling between nanoparticles are prepared. These electrodes present a spongy-like nanostructure in which the dimension of native nanoparticles is preserved, resulting in a huge surface area. Cyclic voltammetry studies reveal that there are significant contributions to the total stored charge from both intercalation capacitance and pseudocapacitance, with a remarkable 50% of the total charge deriving from this second effect. Fast and reversible colouration occurs, with an optical modulation of similar to 60% in the range of 315-1660 nm, and a colouration efficiency of 25.1 cm(2) C-1 at 550 nm. This combination of pseudocapacitance and electrochromism makes the sol-gel derived titania thin films promising candidates for multifunctional 'smart windows'.
keywords
TIO2 THIN-FILMS; LI+ ION INSERTION; PHOTOCATALYTIC ACTIVITY; ANATASE; PERFORMANCE; ANODE; FABRICATION; ELECTRODES; NANOTUBES; NANODOTS
subject category
Nanoscience & Nanotechnology; Materials Science, Multidisciplinary; Physics, Applied
authors
Giannuzzi, R; Prontera, T; Tobaldi, DM; Pugliese, M; De Marco, L; Carallo, S; Gigli, G; Pullar, RC; Maiorano, V
our authors
David Maria Tobaldi
Researcher
Rob Pullar
Collaboratoracknowledgements
The authors gratefully aknowledge Progetto FISR-C.N.R. 'Tecnopolo di nanotecnologia e fotonica per la medicina di precisione'-CUP B83B17000010001, Apulia regional project 'MOSAICOS-MOSAici Interattivi eCO-Sostenibili', Cod. HOQ3PM3-CUP B37H17004900007, Apulia regional project 'FONTANAPULIA-Fotocatalizzatori nanostrutturati e radiazione UV per un'acqua piu pulita' Cod. WOBV6K5CUP B37H17005230007 for funding.; R C Pullar thanks FCT (Fundacao para a Ciencia e Tecnologia, Portugal) Grant IF/00681/2015. This work was partly developed within the scope of the project CICECOAveiro Institute of Materials, UIDB/50011/2020 & UIDP/50011/2020, financed by national funds through the FCT/MEC and when appropriate co-financed by FEDER under the PT2020 Partnership Agreement. David Maria Tobaldi is overly grateful to FCT and to Portuguese national funds (OE), through FCT, I.P., in the scope of the framework contract foreseen in the numbers 4, 5 and 6 of the article 23, of the Decree-Law 57/2016, of August 29, changed by Law 57/2017, of July 19.