Evaluation and Optimization to Recycle Used TiO₂Photoelectrode for Dye-Sensitized Solar Cells

Abstract

This study proposes a method for recycling and activating the titanium oxide (TiO2)/fluorine-doped tin oxide (FTO) photoanode in dye-sensitized solar cells (DSCs) by repeated dye adsorption and desorption processes using various desorption agents. This simple and convenient method could be utilized to activate TiO2photoelectrodes for DSCs after the long-term operation. The devices are immersed in acidic, alkaline, and neutral media of various concentrations for desorption and then are soaked in the N719 solution again. The optimal device had an overall power conversion efficiency (AM 1.5 G, 100 mW/cm2) with 5 × 10−3 M NaOH solution as a desorption agent being 6.44% better than that of devices that had not undergone recycling and activation.

What is necessary to fill the technological gap to design sustainable dye-sensitized solar cells?

“…Dr Renaud Demadrille, in fact, mentioned during his talk at HOPV21 that according to experimental work in his research group, after desorbing the dye in end-of-life photoanodes derived from commercial panels, a simple TiCl 4 treatment (often used for the fabrication of efficient devices) is enough to restore TiO 2 's complete functionality. 112 A similar conclusion was also made by Chen et al 113 although for non-aged devices. Extra considerations should be made in case of flexible plastic substrates, as the UV component of sunlight may degrade the polymeric chains over time, precluding their reuse.…”

Review of State of the Art Recycling Methods in the Context of Dye Sensitized Solar Cells

“…Chen et al used NaOH as a desorbent to purify the front electrode from residual dye, in their case RuL 2 (NCS) 2 -2TBA, also known as N719. After the desorption process, they applied fresh dye to the front electrode to show that old cells could potentially be reused or upgraded with more efficient dyes [51]. In previous experiments, it was even shown that the dyeing process could be accelerated and the dye density improved with each desorption and adsorption process [52].…”

Economic Feasibility for Recycling of Waste Crystalline Silicon Photovoltaic Modules

“…The global annual PV power capacity installed was equal to 76.1 GW in 2016, with a net increase of 49% than 2015 (about 51.2 GW) according to data provided by Solar Power Europe. Reliable predictions on volumes, as well as composition, of future waste streams defined as the EoL management of solar panels are relevant topics in the literature [3,4], supporting the development of circular economies [5].…”