Achieving a superior electrocatalytic activity of carbon cloth via atomic layer deposition as a flexible counter electrode for efficient dye-sensitized solar cells

Abstract

Dye-sensitized solar cell (DSSC) is appealing to renewable energy communities because of its attractive features of low cost, facile assembly and short energy payback time. Nevertheless, the commonly used platinum as the counter electrode (CE) encounters great difficulties in its scarcity and noble nature. Herein, we demonstrate a promising and facile route to attain an earth-abundant, high-conductivity Pt-free flexible CE with the controllable catalytic activity via the atomic layer deposition (ALD) of ZnO as the nanoscale sacrificial template. Our result reveals the electrocatalytic activity of carbon cloth as a function of surface morphology can be successfully tailored by the ALD cycle. It can be ascribed to the interplay of ZnO and carbon during carbothermic reduction, offering the synergetic effects of the defects and oxygen doping on the carbon cloth surface as the enhanced catalytic sites for the regeneration of triiodide into iodide. As a proof of concept, the DSSC using the activated carbon cloth via ALD is enabled to deliver a boosted conversion efficiency by 79%, as compared with that using pristine carbon cloth. Such a promising route can open up a perspective for reaching an earth-abundant, high-conductivity carbon-based flexible CE with the superior catalytic activity for the photoelectrochemical cells.