Electrochemically integrated 2D borophene–graphene architectures for energy and antimicrobial applications

Abstract

Multifunctional two-dimensional architectures with integrated electrochemical and bioactive properties are highly desirable for sustainable energy and environmental technologies. Here, a non-toxic electrochemical exfoliation route is demonstrated for synthesizing borophene–graphene hybrid sheets, addressing the long-standing challenge of poor electrical conductivity in boron-based systems. Ultrasonication of graphite foils enables the effective incorporation of boron through defects, followed by controlled electrochemical exfoliation in an acidic medium, to yield stable 2D borophene–graphene hybrids. Compared to exfoliated graphene, the hybrids exhibit markedly improved electrochemical performance, achieving a specific capacitance of 254 F g⁻¹ and enhanced charge-transfer kinetics. In hydrogen evolution electrocatalysis, the hybrids reduce the overpotential at −100 mA cm⁻² by ∼475 mV relative to graphene and exhibit a Tafel slope of 92 mV dec⁻¹, which is superior to that of HER catalysts that are free of noble metals. Beyond energy applications, the hybrids demonstrate pronounced antimicrobial efficacy, achieving a reduction of more than 91% in mixed microbial cultures within 4 hours. This work establishes borophene–graphene hybrids as a scalable 2D platform that bridges high-performance energy storage, durable hydrogen evolution, and antimicrobial engineering.