Integration of hierarchical tin Sulfide@Sulfur-Doped carbon porous composites with enhanced performance for triiodide reduction

Constructing composites with positively synergistic effect is deemed as an effective strategy to further improve photovoltaic performance of dye-sensitized solar cells (DSSCs). However, the controllable synthesis of composites with intimate interface is still a big challenge. In this work, the solvothermal synthesis using SnCl2 and SnSO4 as tin source allows to grow the SnS microspheres (cSnS) and irregular SnS (sSnS). Subsequently, the hierarchical tin [email protected] carbon porous composites ([email protected]) have been ingenious synthesized by using SnCl2 as tin source through a facile hydrothermal method followed by the pyrolysis of coated glucose containing sulfur species under the nitridation atmosphere. As expected, the as-designed [email protected] exhibited outstanding catalytic activity for triiodide reduction reaction (IRR) accompanying with a photoelectric conversion efficiency (PCE) of 7.54%, which reaches as high as 98.7% to that of the Pt (7.64%), as well as higher than that of the cSnS (6.21%) and sSnS (5.20%) in parallel. Compared with cSnS and sSnS, the further enhanced performance of [email protected] can be mainly attributed to the more exposed active sites, the effective permeation of electrolyte, the decreased resistance, intimate interface and synergistic effect between SnS and S-doped carbon. Our discovery provides an extensible pathway to develop the active-site-enriched composites with beneficial structures in the field of the energy conversion.