Recent advances in ecofriendly 2D monoelemental bismuthene as an emerging material for energy, catalysis and biomedical applications

Since the discovery of graphene, two-dimensional (2D) materials have been established as a vibrant research topic in the fields of energy and catalysis. Among them, 2D mono-elemental bismuthene has attracted interest from researchers owing to its unique electrical, mechanical, optical and chemical properties. In addition, low toxicity and biocompatibility make it a promising material for various applications, such as energy, optoelectronics, catalysis and biomedical sciences. 2D bismuthene with a large bulk gap is a good candidate as a room-temperature topological insulator, and it also exhibits high cyclability in battery application and displays air stability. Furthermore, its high surface area and excellent electrochemical activity make it a potential electrocatalyst for energy conversion. Thus, considering all the fascinating aspects of bismuthene, our aim is to exclusively review the recent advances in 2D monoelemental bismuthene, its properties, synthesis techniques and applications in energy, catalysis and biomedical sciences. This study initially gives an overview of its properties, such as structural, topological, conducting, chemical, carrier mobility, ferroelectric and thermal. Subsequently, we discuss the facile synthesis of bismuthene through chemical vapour deposition, physical vapour deposition, chemical exfoliation, mechanical exfoliation and liquid-phase exfoliation. Further, we present its applications in electrochemical and photocatalytic processes, such as hydrogen evolution reaction, sensing and CO2 reduction, then in optoelectronics, supercapacitors, and batteries, and finally in biomedical applications.