Most cited article - PubMed ID 36979527
Sensing Properties of g-C3N4/Au Nanocomposite for Organic Vapor Detection
2D nanomaterials like transition metal dichalcogenides (TMDs), MXene, nitrides, and black phosphorus-based gas sensors have garnered extensive attention in recent decades. The extra ordinary physicochemical and electrical properties of 2D nanomaterials make them highly sensitive toward gas molecules at room temperature. However, despite their potential, the current gas sensing technology suffers from inadequate selectivity, inaccurate detection and environmental instability. This review provides an overview of recent developments in surface-engineering routes to improve the sensing properties of 2D nanomaterials-based gas sensors. First, it covers emerging 2D nanomaterials, their synthesis routes, and gas-sensing mechanisms. Later on, thoroughly explores renowned surface-engineering strategies such as defect modulation, nanoparticle functionalization, and heteroatom doping to enhance the gas sensing performance. Metal intercalation and partial surface oxidation/reduction approaches are also discussed to tune the sensing characteristics. Furthermore, single-atom catalyst engineering highlights the anchoring of metal atoms on 2D nanomaterials to achieve enhanced atom utilization, leading to better catalytic sensing activities. The engineering techniques introduce effective surface sensitization, modulated carrier concentration in 2D materials. This review outlines the key objectives of surface-engineering strategies to overcome the limitations of hybrid materials and pave the way for next-generation sensors with enhanced sensing performance to impact a wide range of applications.
- Keywords
- 2D materials, gas sensing,
- Publication type
- Journal Article MeSH
- Review MeSH
Graphene oxides (GOs) and hydrogen-terminated nanocrystalline diamonds (H-NCD) have attracted considerable attention due to their unique electronic structure and extraordinary physical and chemical properties in various applications, including gas sensing. Currently, there is a significant focus on air quality and the presence of pollutants (NH3, NO2, etc.), as well as volatile organic compounds (VOC) such as ethanol vapor from industry. This study examines the synthesis of GO, reduced graphene oxide (rGO), thiol-functionalized graphene oxide (SH-GO), and H-NCD thin films and their combination in heterostructures. The materials were analyzed for their ability to detect NO2, NH3, and ethanol vapor at room temperature (22 °C). Among the tested materials, the SH-GO/H-NCD heterostructure exhibited the highest sensitivity, with approximately 630% for ethanol vapor, 41% for NH3 and -19% for NO2. The SH-GO/H-NCD heterostructure also demonstrated reasonable response (272 s) and recovery (34 s) times. Cross-selectivity measurements revealed that the heterostructure's response to ethanol vapor at 100 ppm remained dominant and was minimally affected by the presence of NH3 (100 ppm) or CO2 (100 ppm). The response variations were -1.3% for NO2 and 2.4% for NH3, respectively. These findings suggest that this heterostructure has the potential to be used as an active layer in low-temperature gas sensors. Furthermore, this research proposes a primary mechanism that explains the enhanced sensor response of the heterostructure compared with bare GOs and H-NCD layers.
