Pt–Co and Pt–Ni hollow nanospheres supported with PEDOT:PSS used as high performance counter electrodes in dye-sensitized solar cells

• Pt–Co and Pt–Ni binary alloy hollow nanospheres are synthesized by solution reaction.
• The binary alloys on PEDOT:PSS show high conductivity and electrocatalytic activity.
• The DSSCs with Pt–Co and Pt–Ni CEs achieve PCE of 9.027% and 8.23%, respectively.
• The both PCEs are higher than the PCE for the DSSC with Pt CE (7.96%).

Binary alloy platinum–cobalt (Pt–Co) and platinum–nickel (Pt–Ni) hollow nanospheres are prepared by using a simple solution reaction method. Poly(3,4-ethylenedioxy thiophene):polystyrene sulfonate (PEDOT:PSS) as supported layer further enhance the binary platinum alloy electrochemical properties. The prepared binary platinum alloys are observed with hollow nanosphere structure. The cyclic voltammogram and electrochemical impedance spectroscopy measurement indicate that Pt–Co and Pt–Ni hollow nanospheres on PEDOT:PSS (PC-PP and PN-PP) electrodes have high conductivity and catalytic performance. Under simulated white solar light irradiation with intensity of 100 mW cm−2 (AM 1.5), the dye-sensitized solar cells (DSSCs) based on PCPP and PNPP counter electrodes achieve power conversion efficiencies of 9.02% and 8.23%, respectively, which are higher than the efficiency for the DSSC based on Pt counter electrode (7.96%).