High-performance boron nitride/graphene oxide composites modified with sodium thiosulfate for energy storage applications.

Abstract

Two-dimensional (2D) hybrid materials, particularly those based on boron nitride (BN) and graphene oxide (GO), have attracted significant attention for energy applications owing to their distinct structural and electronic properties. BN/GO composites uniquely combine the mechanical strength, thermal stability and electrical insulation of BN with the high conductivity and flexibility of GO, creating advanced materials ideal for the fabrication of batteries, supercapacitors and fuel cells. These hybrids offer synergistic effects, enhanced charge transport, increased surface area, and improved chemical stability, making them promising candidates for high-performance energy systems. Despite their potential, challenges, such as achieving scalable synthesis and uniform BN-GO dispersions and poor interface compatibility, have limited the widespread adoption of BN-GO hybrids. To address these limitations, this study is focused on the scalable synthesis of BN-GO composites via a liquid-phase exfoliation method with ultrasonication, followed by preparation of sodium thiosulfate (STS)-functionalized BN-GO composites (STBG), which exhibited high electrochemical properties suitable for energy storage. The structural identification was confirmed using FT-IR, Raman, XRD, and UV-vis spectroscopy. Thermal stability of the samples was assessed by TGA, while their morphological analysis was performed using HR-TEM, TEM, and SEM. Pristine BN showed negligible efficiency, whereas STS functionalization elevated the efficiency of STBN to 81.7%, while the incorporation of GO in STBG1 and STBG2 boosted their efficiency to 89.3% and 83.3%, respectively. STBG1 exhibited a nearly rectangular, symmetrical CV curve at various scan rates, demonstrating excellent capacitive behavior. Furthermore, it achieved the highest specific capacitance of 115.82 F g^-1 at a current density of 1 A g^-1, together with a coulombic efficiency of 89.3%, indicating its superior charge transfer and minimal energy loss. Additionally, STBG1 retained 87.3% of its capacity, while STBG2 retained 81.7% even after 3000 charge/discharge cycles. These findings highlight that STBG1 is a promising composite with high capacitance, strong rate capability, and exceptional coulombic efficiency, making it a viable candidate for next-generation energy storage systems.