Heteroatom tri-doped porous carbon derived from waste biomass as Pt-free counter electrode in dyesensitized solar cells

Strategies for environmentally friendly reutilization of waste biomass are highly desirable nowadays. Meanwhile, seeking Pt-free electrocatalysts for triiodide reduction with both high catalytic activity and low cost is critical for the development of dye-sensitized solar cells (DSCs). In the study, heteroatom tri-doped porous carbons (TPCs) were prepared via carbonization of a typical food waste (fish waste) and explored as a counter electrode (CE) in a DSC. The as-prepared carbon materials possessed a porous structure with a large BET surface area of 2933 m(2) g(-1), while being simultaneously naturally doped by three heteroatoms (N, P and S). More importantly, the resultant N, P, S-tri-doped porous carbon exhibited outstanding electrochemical activity towards triiodide reduction with good stability. Moreover, the DSC with the optimized TPC electrode showed a power conversion efficiency of 7.83%, which is comparable to the device with a costly Pt-based CE (8.34%), measured under one sun illumination (AM 1.5G). This work demonstrates that carbonization of fish waste offers a cost-effective approach to prepare multifunctional carbon materials for advanced energy applications.