Recent developments in synthesis, properties, and applications of 2D Janus MoSSe and MoSexS(1-x) alloys

The Janus MoSSe and alloy MoS_xSe_(1-x), belonging to the family of two-dimensional (2D) transition metal dichalcogenides (TMDs), have gained significant attention for their potential applications in nanotechnology. The unique asymmetric structure of Janus MoSSe provides intriguing possibilities for tailored applications. The alloy MoS_xSe_(1-x) offers a tunable composition, allowing for the fine-tuning of the properties to meet specific requirements. These materials exhibit remarkable mechanical, electrical, and optical properties, including a tunable band gap, high absorption coefficient, and photoconductivity. The vibrational and magnetic properties also make it a promising candidate for nanoscale sensing and magnetic storage applications. Properties of these materials can be precisely controlled through different approaches such as size-dependent properties, phase engineering, doping, alloying, defect and vacancy engineering, intercalation, morphology, and heterojunction or hybridisation. Various synthesis methods for 2D Janus MoSSe and alloy MoS_xSe_(1-x) are discussed, including hydro/solvothermal, chemical vapour transport, chemical vapour deposition, physical vapour depositio, and other approaches. The review also presents the latest advancements in Janus and alloy MoSSe-based applications, such as chemical and gas sensors, surface-enhanced Raman spectroscopy, field emission, and energy storage. Moreover, the review highlights the challenges and future directions in the research of these materials, including the need for improved synthesis methods, understanding of their stability, and exploration of new applications. Despite the early stages of research, both the MoSSe-based materials have shown significant potential in various fields, and this review provides valuable insights for researchers and engineers interested in exploring its potential.