Publication

Abstract : Group VI transition metal dichalcogenides (TMDs) have attracted significant attention due to their exceptional coordination-driven surface properties, making them particularly well-suited for chemiresistive probes. Chemiresistive probing of acetone via headspace analysis at lower concentrations finds applications in healthcare and environmental monitoring. These chemiresistive probes employing Group VI TMDs are becoming popular due to their favourable physicochemical and electronic properties. This critical review presents insights into the atomistic-level surface coordination of entire Group VI TMDs, their material-engineering approaches, and their device-level integration for acetone-sensing probes. The surface interfacial coordination environments, with hybridization of metal d-orbitals, in acetone sensing are highlighted through atomistic schemes such as metal-mediated localized Schottky junctions, Janus derivatives, dipole-driven physisorption, type II staggered band alignment, and photo-simulated dynamics. Further, the material engineering strategies, such as defect, morphology, and heterojunction, for tuning the acetone-sensing behaviour through d-orbital splitting in Group VI TMDs are critically emphasized along with the material-level challenges. Defect engineering, including metal implantation and impurity doping, is addressed to promote the formation of acceptor-level defects and free oxygen radicals. In morphological engineering, core-shell architectures, quantum confined nanostructures, and thickness engineering are highlighted. The control of interfacial charge transfer through band engineering is a central focus of heterojunction engineering. The trade-off between the fundamental coordination of Group VI TMDs, the application of effective engineering strategies, and a rational basis for advancing high-performance sensing probes in healthcare, along with their translational design challenges and future perspectives, is presented.