Rational design of efficient counter electrode with Co/Co1P1N3 atomic interface for promoting catalytic performance

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.