Manipulation of flexible carbon cloths for stable and efficient catalysts in dye-sensitized solar cells

Abstract

• The CC with preferred characteristics can be facilely manipulated. • The catalytic activity and stability of CE can be improved via underlying supports. • The simultaneously improved PCE and stability are achieved by using an optimal CE. The highly stable and efficient dye-sensitized solar cell (DSC) strongly relies on the catalytic activity and stability of the counter electrode (CE) in the electrolyte. Herein, we explore an effective and eco-friendly method of making a high catalytic activity of CE with the improved stability by utilizing the high-conductivity carbon cloth (CC) with great corrosive resistance as flexible carbon-based supports for nanoparticle-based catalysts and using Pt as an example. A variety of CCs with different characteristics are facilely manipulated by the hybrid solution-based surface treatments, enabling to systemically investigate the influence of different CCs on the performance of Pt catalysts. The result shows that the surface activated CC with properly porous structure and wetting surface facilitates the accommodation of catalysts and the diffusion of redox couple within the carbon fiber network. The existence of active sites such as defective structures and oxygen-containing groups on CCs effectively serve as the nucleation or adsorbed sites of Pt catalysts, which simultaneously improve the catalytic and stable performance of CE. Multi-scan cyclic voltammetry indicates that a preferred surface activated CC as Pt catalyst support retains 95.9% of its initial catalytic ability in comparison with the typical platinized fluorine-doped tin oxide (76%). The DSC using the desirable Pt-decorated CC displays an improvement of 49% in conversion efficiency as compared with that using the nonoptimal counterpart. Such improvements highlight the feasibility of simply manipulating the characteristics of underlying flexible carbon-based supports in pursuit of the high catalytic activity and stability of CEs in DSCs.