Surface Engineering of Borophene as Next-Generation Materials for Energy and Environmental Applications

This review provides an insightful and comprehensive exploration of the emerging 2D material borophene, both pristine and modified, emphasizing its unique attributes and potential for sustainable applications. Borophene's distinctive properties include its anisotropic crystal structures that contribute to its exceptional mechanical and electronic properties. The material exhibits superior electrical and thermal conductivity, surpassing many other 2D materials. Borophene's unique atomic spin arrangements further diversify its potential application for magnetism. Surface and interface engineering, through doping, functionalization, and synthesis of hybridized and nanocomposite borophene-based systems, is crucial for tailoring borophene's properties to specific applications. This review aims to address this knowledge gap through a comprehensive and critical analysis of different synthetic and functionalisation methods, to enhance surface reactivity by increasing active sites through doping and surface modifications. These approaches optimize diffusion pathways improving accessibility for catalytic reactions, and tailor the electronic density to tune the optical and electronic behavior. Key applications explored include energy systems (batteries, supercapacitors, and hydrogen storage), catalysis for hydrogen and oxygen evolution reactions, sensors, and optoelectronics for advanced photonic devices. The key to all these applications relies on strategies to introduce heteroatoms for tuning electronic and catalytic properties, employ chemical modifications to enhance stability and leverage borophene's conductivity and reactivity for advanced photonics. Finally, the review addresses challenges and proposes solutions such as encapsulation, functionalization, and integration with composites to mitigate oxidation sensitivity and overcome scalability barriers, enabling sustainable, commercial-scale applications.