Photoanode for Aqueous Dye‐Sensitized Solar Cells based on a Novel Multicomponent Thin Film

Abstract

Most of the dye-sensitized solar cells (DSSCs) developed so far use organic electrolytes and water-sensible sensitizers. The search for aqueous DSSCs, a promising technology for solar-energy conversion, implies finding materials that are stable in aqueous solution. In this study, Prussian blue (PB) was utilized as an innovative sensitizer in a photoanode for DSSCs and a novel synthetic approach to a carbon nanotubes/TiO /PB nanocomposite thin film was developed. The photoresponse was evaluated in a total aqueous electrolyte, and photocurrents of 600 μA cm were achieved.

Liquid–liquid interfaces: a unique and advantageous environment to prepare and process thin films of complex materials

“…62 Interestingly, the catalyst thin film can be easily removed at the end of the process, washed with water and reused, remaining structurally and morphologically integrate and presenting the same performance for at least 10 catalytic cycles. 62 CNT-based nanocomposite thin films with metals 49 or oxides 63 can be prepared from the components initially dispersed in each one of the liquid phases. For example, a CNT/ AuNP thin film at the dichloromethane/water interface has been obtained starting from MPTMS-capped AuNPs dispersed in dichloromethane and SWCNTs dispersed in water with a surfactant (Triton X-100).…”

“…49 CNT/TiO 2 thin films were prepared starting from Fe-filled CNTs and commercial TiO 2 particles. 63 A toluene/water interface was prepared with the CNTs dispersed in toluene and the TiO 2 dispersed in water. The two liquids were mixed and stirred for 2 h. The self-assembled film formed at the L/L interface when the stirring was interrupted was transferred to glass/ITO substrates.…”

“…The film was characterized by a homogeneous distribution of the two components along the substrate, with CNTs well dispersed among TiO 2 particles, resulting in very effective contact. 63 This film was used as a precursor for a CNT/ TiO 2 /PB nanocomposite, by the in situ electrosynthesis of PB by cyclic voltammetry between the iron species encapsulated into CNT cavities and the K 3 [Fe(CN) 6 ] in aqueous solution present in the electrolyte. The tri-component nanocomposite was used as a photoanode in a dye-sensitized solar cell (DSSC), presenting some breakthroughs, such as the demonstration of the possibility of use of PB as an absorber in a DSSC, the mixture of the absorber and the semiconductor (TiO 2 ) in a single film and adding a good electronic conductor (CNTs) to facilitate the electron transfer processes (from absorber to semiconductor to electrode).…”

“…The intimate contact between the components, which is due to the specific way in which the film was prepared, was demonstrated to be responsible for the improved photocurrent response observed. 63 Bi-component films based on PVP-capped silver nanowires (NWs) and oleylamine-capped gold nanostructures have been prepared by Zhang et al 64 The Ag NWs were dispersed in water and the Au-NPs dispersed in chloroform. The two dispersions were mixed and vigorously shaken, resulting afterwards in a Ag-NW/Au-NP film around the water phase.…”

A Smart Flexible Solid State Photovoltaic Device with Interfacial Cooling Recovery Feature through Thermoreversible Polymer Gel Electrolyte

“…However, to make DSSCs a practically viable and sustainable technology, it is important to develop facile and costeffective ways of fabricating eco-friendly DSSCs with long-term stability. As such, purely water-based DSSCs (using water as a hazard-free solvent) [3][4][5][6][7][8][9] offer such a combination of features, thereby promising to be a more sustainable alternative to the other types of solar cells. To demonstrate the practicality of DSSCs for wide applications, devices with a number of different features like use of flexible electrodes, [10,11] water-based gel electrolytes, [3,12] smart electrolytes, [13] and stretchable conducting fibers, [14,15] have been developed.…”