Emergence of phosphorene 2D materials for high-performance supercapacitor electrode applications: A brief review

Phosphorene, a two-dimensional compound derived from black phosphorus, has been in the limelight for its potential in energy storage, particularly as a high-performance supercapacitor electrode material. The structural and electronic properties of this material, including high charge-carrier mobility, tunable bandgap, large surface area, and high mechanical flexibility, position it well for next-generation energy storage devices. This review is dedicated to the development of phosphorene in supercapacitor devices, discussing synthesis routes, electrochemical performance, improvement strategies and avenues for future work. Various synthesis methods employed for phosphorene include mechanical exfoliation, liquid-phase exfoliation, and chemical vapour deposition, and the challenges faced in mass production and stability. The electrochemical activity of phosphorene-based electrodes is evaluated considering charge storage mechanism, capacitance and stability and its comparison is drawn with its efficiency against other highly used two-dimensional materials like graphene, MXenes and Transition metal Dichalcogenides. Besides, different strategies that were created to increase the electrochemical activity of phosphorene via heterostructure creation, surface functionalization, doping and hybridization with conductive nanomaterials are discussed. Despite its superior properties, phosphorene is currently suffering from extreme challenges, including fast oxidation in air, structural degradation and scalability, which hinder its commercialisation. The review addresses potential solutions to these limitations, such as encapsulation methods, composite material engineering, and modifications to environmental stability. Ultimately, future research directions are outlined, highlighting the importance of interdisciplinary approaches to enhance phosphorene's stability, performance and integration into commercial supercapacitor technologies. By recapitulating recent progress and addressing the challenges at hand, the review provides critical insights into the evolving position of phosphorene within the broader research community on supercapacitor electrode materials. Further studies and tuning of phosphorene-based energy storage systems hold promise for practical applications in sustainable energy devices. Unlike previous reviews that mainly cover phosphorene's structure and fundamental electrochemistry, this review uniquely combines synthesis challenges, pathways for stability degradation, strategies to enhance performance, and prospects for the commercialisation of phosphorene-based supercapacitors.