Chapter 5: Facile Synthesis and Characterization of Strontium Sulfide Incorporated Graphitic Carbon Nitride Nanocomposite for Energy Storage Applications

Strontium sulfide/graphitic carbon nitride (SrS/g-C₃N₄) nanocomposites were successfully synthesized via a facile hydrothermal method to improve the optical and electrochemical performance of SrS for energy storage and optoelectronic applications. The synthesized nanohybrids were systematically characterized using X-ray diffraction (XRD), UV–Vis spectroscopy, photoluminescence (PL), Raman spectroscopy, and electrochemical techniques. XRD analysis confirmed the successful formation of the composite and revealed enhanced crystallinity with increasing g-C₃N₄ content. UV–Vis results demonstrated a reduced optical band gap, indicating improved visible-light absorption after g-C₃N₄ incorporation. PL spectra exhibited a characteristic emission peak at 445 nm with suppressed charge carrier recombination, while Raman analysis verified the successful integration of g-C₃N₄ into the SrS matrix. Electrochemical investigations demonstrated that the optimized 0.3% SrS/g-C₃N₄ nanohybrid delivered a high specific capacitance of 850 F g⁻¹ at a current density of 2 A g⁻¹, together with an energy density of 38.19 Wh kg⁻¹ and a power density of 500 W kg⁻¹. The enhanced performance is attributed to the synergistic interaction between SrS and g-C₃N₄, which facilitates charge transport and increases electroactive sites. These results demonstrate that SrS/g-C₃N₄ nanohybrids are promising multifunctional materials for advanced high-performance supercapacitor applications as well as optoelectronic devices.