SnS2-gC3N4/rGO Composite Paper as an Electrode for High-Performance Flexible Symmetric Supercapacitors

•A flexible SnS2-gC3N4/rGO paper was prepared by vacuum filtration of the composite dispersion containing GO and the SnS2-gC3N4.•SnS2-gC3N4 with flower-like morphology helped the ions to be easily charged and discharged by intercalating between the graphene layers.•SnS2-gC3N4/rGO symmetric supercapacitor exhibited a high capacitive performance of 403 F g-1 at 1 A g-1.•Lighting up a red LED using just a single prototype device showed the potential practical applicability of SnS2-gC3N4/rGO paper electrode. The flexible, free-standing, durable SnS2-gC3N4/rGO paper material was prepared by vacuum filtration of the composite dispersion containing GO and the SnS2-gC3N4 composite structure which is synthesized by a simple hydrothermal method. The as-prepared SnS2-gC3N4/GO composite paper was converted to SnS2-gC3N4/rGO paper material by applying a chemical reduction process. SnS2-gC3N4/rGO paper material was characterized by using FESEM, XRD, Raman, XPS, and EIS spectroscopy techniques. The SnS2-gC3N4 composite, a porous flower-like structure, uniformly intercalated between the graphene nanosheets exhibited excellent mechanical stability, greatly improved active surface areas, and enhanced surface porosity, in comparison with the pristine rGO paper. SnS2-gC3N4/rGO composite paper material show a highest specific capacitance of 532 F g-1 at 1 A g-1 and good cycling stability with capacitance retention of 60 % at 4 A g-1 after 5000 cycles. Moreover, SnS2-gC3N4/rGO composite paper demonstrate an excellent supercapacitor performance compared to the gC3N4/rGO paper and pristine rGO paper. The flexible symmetric supercapacitor based on SnS2-gC3N4/rGO composite electrode exhibits remarkable mechanical flexibility, high capacitive performance (403 F g-1 at 1 A g-1) and high cycle stability (63.8% at 4 A g-1 after 1500 cycles). As a result, SnS2-gC3N4/rGO composite paper material is expected to be a promising material for high-performance energy storage applications.