Well-defined heteroatom-rich porous carbon electrocatalyst derived from biowaste for high-performance counter electrode in dye-sensitized solar cells

A low-cost and widely available natural resource of pomelo peel (PP) was used as a precursor to fabricate multiple active components synergistically driven heteroatom-doped porous carbon in counter electrode of dye-sensitized solar cells. The electrocatalyst was prepared via a ZnCl2 activation combined with a post-carbonization process under an N2 atmosphere (noted as PPA). The resulting PPA counter electrode with well-defined porosity and abundant heteroatoms possesses a very similar high power conversion efficiency of 8.29% compared with Pt counterpart (8.24%) based on the liquid I3−/I− electrolyte. Furthermore, PPA has a strong acid resistance, after PPA was treated with 2 M HCl (noted as PPE), only resulting in a slightly decreased PCE (8.13%), the little change of photovoltaic performance is mainly ascribed to the stable structure and powerful interaction between metals and support that display excellent electrocatalytic activities. The superior electrochemical performance is attributable to the synergistic effect of chemical activation and heteroatom-doping of PP-derived porous carbon coupled with well-defined pores and uniformly distributed elemental composition. Given these excellent electrocatalytic properties, structural stability, facile to large-scale preparation, the porous heteroatom doping carbon has a potential application for an alternative electrocatalyst of triiodide reduction reaction (IRR) in practical high-performance DSC devices.