▎ 摘 要
This work presents an efficient and stable platinum-free shear-exfoliated graphene nanoplatelets (SEGNP) based counter electrode (CE) for dye-sensitized solar cells (DSSCs). The SE-GNP is prepared by the simple, low cost and eco-friendly high-shear liquid-phase exfoliation technique in bulk using natural graphite flakes as a starting material in an aqueous medium. Detailed electrochemical studies demonstrate that SE-GNP-based CE offers a superior electrocatalytic activity for the redox reaction of I/I-3 redox couple with an improved charge transfer kinetics and the exchange current density at the electrode/electrolyte interface, compared to the standard Pt CE. The SE-GNP-based counter electrode shows exceptionally high stability (>3000 h) and efficiency (eta = 7.6%) under constant illumination at a negligible drop in DSSCs' performance. (C) 2020 Elsevier B.V. All rights reserved.