Borophene growth via chemical vapor deposition for supercapacitor applications

Abstract

This research investigates the controlled growth of borophene, a two-dimensional (2D) material composed of boron atoms arranged in atomically thin layers, using chemical vapor deposition (CVD) and explores its potential in supercapacitors. Borophene, similar to graphene, offers high electrical conductivity and tensile strength, making it a promising candidate for energy storage applications. However, synthesizing and stabilizing borophene structures in large areas remains a significant challenge, limiting its widespread adoption. Our study employs CVD to address these challenges, particularly in terms of controlling the thickness, crystallinity and uniformity. Key parameters in the growth process, such as reaction duration, temperature, precursor materials and ratios, carrier gases, and pressure, were optimized using copper substrates as catalysts. Thickness control ranging from approximately 0.9 nm to 9 nm with nearly full substrate coverage was achieved, demonstrating significantly improved uniformity compared to previous reports. These CVD grown borophene structures are employed as electrode materials for supercapacitors, achieving a specific areal capacitance of 44.5 mF cm⁻² at a scan rate of 5 mV s⁻¹ and a specific gravimetric capacitance of 4238 F g⁻¹ at a scan rate of 5 mV s⁻¹. This study reveals that borophene-based supercapacitors hold considerable potential due to their electrical and structural properties, characterized by high crystallinity and layered 2D structures that facilitate ion intercalation, indicating exceptional performance in future devices and applications.