Multifunctional nanostructured materials to devices

抄録

Multifunctional materials have attained inevitable growth in recent years due to their unique properties and wide range of applications. Recently, emerging 2D layered materials possess excellent electrical, chemical, optical, and mechanical properties. Moreover, its tunable bandgap and ability to switch between metallic and semiconducting behavior allows for versatile electronic applications, including field-effect transistors, sensors, photodetectors, etc. Additionally, its unique surface and optical properties, like large surface area, strong light-matter interactions, and high light absorption, have led to its application in catalysis, photonics, and energy harvesting devices. This abstract aims to provide an overview of the key aspects and potential applications of MoS₂ as a 2D layered multifunctional material. We have investigated 2D layered materials for diverse applications and achieved state-of-art results by carefully tuning their properties as per the requirement. In our laboratory, thermoelectric energy conversion is the most explored application of MoS2. We have studied the thermoelectric properties of MoS₂ in all the available forms ranging from bulk to thin-film to flexible thick films to wearable fabrics, and have employed diverse strategies to improve its performance. We have formed MoS₂/MoO₃ hierarchical structures by hydrothermal method and studied the effect of the interface in its thermoelectric performance. With the simultaneous enhancement of electrical conductivity and Seebeck coefficient along with reduced thermal conductivity, we have achieved a record high zT of 1.18 at 600 K. This was attributed to enhanced phonon scattering and improved electrical conductivity by zero-barrier charge injection at MoS₂/MoO₃ interface [1]. Similarly, we have grown a few-layer MoS₂ on 290 nm-SiO₂/Si by a two-zone atmospheric pressure chemical vapor deposition technique and investigated its thermoelectric properties. Here, we observed the decoupling of electrical conductivity and Seebeck coefficient after 592 K resulting in an enhanced power factor of 116 nW/mK² at 734 K [2]. To overcome the challenges associated with using binders in the fabrication and enhance flexibility, we processed in-situ binder-free growth of MoS₂ nanosheets on conductive carbon fabric for wearable thermoelectric applications. We fabricated a wearable thermoelectric generator using MoS₂ and generated an output voltage of 1.2 mV at a temperature difference of 20 K. This paves a promising route for the future development of wearable thermoelectric. Further, we employed MoS₂ as the catalyst to degrade the environmental pollutants under light irradiation. MoS₂, when composited with ZnS, degraded the pollutants in 32 min (99.89%). This was attributed to the interfacial charge carriers being transferred between MoS₂ and TiO₂. We have constructed a MoS2-based gas sensor for the highly sensitive room temperature NO₂ sensing and have studied the effect of doping (Co, Ni) in its sensing performance [3]. Parallelly, we fabricated a solid-state asymmetric supercapacitor using Ni-doped MoS₂ for energy storage applications[4]. The DSSC device assembled with as-fabricated N-GQD@MoS₂@rGO possessed a superior power conversion efficiency of 4.65% due to the enhanced electrochemical active site and electrical conductivity property of rGO and MoS₂ [5].