Design of SrS/FeS integrated with reduced graphene oxide for revolutionary applications in hybrid supercapacitors and hydrogen production

초록

Hybrid supercapacitors (HSCs) have the potential to deliver high power, high charging and discharging rates, and long life. Transition metal sulfides with reduced graphene oxide (rGO), a two-dimensional layered material with a large surface area, possess good conductivity and redox capability, enabling design of the HSCs. To address the issue of low performance, SrS/FeS doped with reduced graphene oxide (rGO)//activated carbon is fabricated to promote the redox activity and structural strength. Doping of SrS/FeS with rGO leads to the formation of a hybrid material that is more conductive, possesses higher capacitance, and has longer cycling life. The interaction between metal sulfides and carbon layers facilitates faster movement of charge and storage of more energy. We prepared SrS/FeS doped with rGO through a low-cost, simple hydrothermal process. XRD identified the crystal structure, while SEM revealed homogeneous dispersion of SrFeS on rGO sheets. CV and GCD tests demonstrated intense pseudocapacitive performance. The hybrid sample provided a high specific capacity of 3385.7 C g-1, an energy density of 95 Wh kg-1, and a power density of 2465 W kg-1. It showed 94.60% capacity retention after 10 000 cycles. The rGO enhanced conductivity and structural stability, whereas SrS/FeS enhanced redox performance and inhibited graphene restacking. Besides, the composite electrode showed a lower overpotential of 54 mV and a Tafel slope of 42 mV dec-1. The hybrid electrode presented double-layer capacitance, pseudocapacitance behavior, and remarkable performance.

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