Optimized photoelectric catalysis with enhanced durability in rGO-interconnected nanocarbon-confined cobalt nanoparticles

Abstract

Rational construction of the electrocatalytic centers is effective yet challenging for designing the high-efficient-stable counter electrodes (CEs) in dye-sensitized solar cells (DSSCs). Herein, the Prussian blue analogue (PBA)-derived nanocarbon-confined cobalt nanoparticles were successfully interconnected by the reduced graphene oxide network (Co-NC@rGO-600), and employed as the CE. In this interconnecting-and-confining scenario, the ambient graphitic carbon-shell and rGO network not only establish a communicating charge transfer bridge, but also greatly hinder the corrosion of the cobalt core in iodine electrolyte, thus endowing the catalyst with fast reaction kinetics and fine durability. Simultaneously, the nanocarbon-concentrated cobalt active core ensures the composite extraordinary catalytic activity towards the triiodide/iodide redox couple. Finally, the DSSC fabricated with Co-NC@rGO-600 realized a higher power conversion efficiency (PCE = 8.82%) than that of the commercial Pt-based DSSC (7.79%). These results deliver a new avenue to design the promising carbonaceous CE catalyst with optimized active centers, which may play a vital role in DSSCs and wider energy applications.