Synergistic carbon nanotube aerogel – Pt nanocomposites toward enhanced energy conversion in dye-sensitized solar cells

Abstract

With the lab-made carbon nanotube aerogel (CNA) serving as the counter electrode (CE), dye-sensitized solar cells (DSSCs) operated under solar simulator illumination (100 mW cm⁻², AM 1.5 G) demonstrated an overall power conversion efficiency (η) of 8.35%, higher than the η of 5.95 and 7.39% of DSSCs with a multi-walled carbon nanotube (MWCNT) CE and conventional Pt CE, respectively. With only 3.75 wt% Pt nanoparticles to form an aerogel carbon nanotube composite (CNA-3.75 wt% Pt) CE, the corresponding η was further increased to 9.04%. The enhanced performance by introducing Pt nanoparticles is mainly attributed to the improved electrocatalytic activity, reduced charge-transfer resistance (R_ct) at the CE/electrolyte interface, and increased diffusion for the redox couple in the electrolyte. This work provides substantial support for developing low-cost Pt-loaded nanocomposite CEs to further enhance the DSSC performance.