A rational design of an efficient counter electrode with the Co/Co1P1N3 atomic interface for promoting catalytic performance

Abstract

Interface engineering has been demonstrated to have a great effect on designing high performance catalysts. In particular, the interface design at the atomic scale is always a fortress to be overcome by researchers. Herein, we in situ introduced triphenylphosphine into cobalt atom sites in a metal–organic framework via encapsulation and successfully synthesized a cobalt single-atom catalyst with a co-coordinated atomic interface structure of P and N (Co/Co₁P₁N₃). Adopted as a counter electrode (CE) in dye-sensitized solar cells (DSSCs), Co/Co₁P₁N₃ demonstrates a power conversion efficiency (PCE) of 8.51%, outperforming Co/Co₁N₄ (6.62%) counter electrode and commercial Pt (7.88%). We discover that the electron donation from the P dopant can reduce the electrostatic attraction between Co and I⁻ ions, which favor I⁻ desorption processes, sequentially boosting the activity of Co/Co₁P₁N₃.