Organic semiconductors (OSCs) have been extensively studied as sensing channel materials in field‐effect transistors due to their unique charge transport properties. Stimulation caused by its ...environmental conditions can readily change the charge‐carrier density and mobility of OSCs. Organic field‐effect transistors (OFETs) can act as both signal transducers and signal amplifiers, which greatly simplifies the device structure. Over the past decades, various sensors based on OFETs have been developed, including physical sensors, chemical sensors, biosensors, and integrated sensor arrays with advanced functionalities. However, the performance of OFET‐based sensors still needs to be improved to meet the requirements from various practical applications, such as high sensitivity, high selectivity, and rapid response speed. Tailoring molecular structures and micro/nanofilm structures of OSCs is a vital strategy for achieving better sensing performance. Modification of the dielectric layer and the semiconductor/dielectric interface is another approach for improving the sensor performance. Moreover, advanced sensory functionalities have been achieved by developing integrated device arrays. Here, a brief review of strategies used for improving the performance of OFET sensors is presented, which is expected to inspire and provide guidance for the design of future OFET sensors for various specific and practical applications.
Strategies for improving the performance of sensors based on organic field‐effect transistors (OFETs) are summarized, including tailoring molecular structures of the organic semiconductor, modulating the micro/nanostructures of the organic semiconductor layer, modifying the dielectric layer, utilizing organic semiconductor/dielectric interfacial interactions, and integrating arrays of the sensors.
Metal organic framework (MOF)‐derived nitrogen‐enriched nanocarbons have been proposed as promising metal‐free electrocatalysts for oxygen reduction reaction. However, the characteristic microporous ...feature of MOF‐derived carbon determined by the MOF structure significantly hinders the mass transfer and exposure of active sites, resulting in unsatisfactory electrocatalytic performance. Here an in situ confinement pyrolysis strategy that can simply but efficiently transform monodisperse ZIF‐8 polyhedrons to nitrogen‐enriched meso‐microporous carbon (NEMC) frameworks is reported. Using this strategy, 3D NEMC frameworks, 1D NEMC fibers, and 2D NEMC on graphene (NEMC/G) can be successfully obtained. As a metal‐free elctrocatalyst, optimized NEMC/G can reach a comparable electrocatalytic activity with superior stability and methanol resistance to commercial 30 wt% Pt/C catalyst in 0.1 m KOH solution. Such enhanced performance can be ascribed to the stable and highly open network consisting of NEMC and G with fully exposed active sites, thereby leading to durable catalytic activity.
In situ confinement pyrolysis strategy without using any template is proposed to construct nitrogen‐enriched meso‐microporous carbon (NEMC) frameworks from a metal organic framework for use as metal‐free oxygen reduction electrocatalysts. Uing a very simple but effective strategy, the NEMC catalysts with well‐defined 1D–3D morphology can be easily realized and they demonstrate excellent electrocatalytic performance through optimizing the channel structures and nitrogen‐doped sites.
We report a high-performance bi-functional electrocatalyst composed of 3D crumpled graphene (CG)-cobalt oxide nanohybrids. This is the first report on using CG coupled with nanocrystals as both ...oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) catalysts. The nitrogen-doped CG-CoO hybrid exhibits excellent catalytic activity and durability, making it a high-performance non-precious metal-based bi-functional catalyst for both ORR and OER.
Developing photoanodes with efficient sunlight harvesting, excellent charge separation and transfer, and fast surface reaction kinetics remains a key challenge in photoelectrochemical water splitting ...devices. Here we report a new strongly coupled ternary hybrid aerogel that is designed and constructed by in situ assembly of N-deficient porous carbon nitride nanosheets and NiFe-layered double hydroxide into a 3D N-doped graphene framework architecture using a facile hydrothermal method. Such a 3D hierarchical structure combines several advantageous features, including effective light-trapping, multidimensional electron transport pathways, short charge transport time and distance, strong coupling effect, and improved surface reaction kinetics. Benefiting from the desirable nanostructure, the ternary hybrid aerogels exhibited remarkable photoelectrochemical performance for water oxidation. Results included a record-high photocurrent density that reached 162.3 μA cm–2 at 1.4 V versus the reversible hydrogen electrode with a maximum incident photon-to-current efficiency of 2.5% at 350 nm under AM 1.5G irradiation, and remarkable photostability. The work represents a significant step toward the development of novel 3D aerogel-based photoanodes for solar water splitting.
The unique properties of MoS2 nanosheets make them a promising candidate for high‐performance room temperature sensing. However, the properties of pristine MoS2 nanosheets are strongly influenced by ...the significant adsorption of oxygen in an air environment, which leads to instability of the MoS2 sensing device, and all sensing results on MoS2 reported to date were exclusively obtained in an inert atmosphere. This significantly limits the practical sensor application of MoS2 in an air environment. Herein, a novel nanohybrid of SnO2 nanocrystal (NC)‐decorated crumpled MoS2 nanosheet (MoS2/SnO2) and its exciting air‐stable property for room temperature sensing of NO2 are reported. Interestingly, the SnO2 NCs serve as strong p‐type dopants for MoS2, leading to p‐type channels in the MoS2 nanosheets. The SnO2 NCs also significantly enhance the stability of MoS2 nanosheets in dry air. As a result, unlike other MoS2 sensors operated in an inert gas (e.g. N2), the nanohybrids exhibit high sensitivity, excellent selectivity, and repeatability to NO2 under a practical dry air environment. This work suggests that NC decoration significantly tunes the properties of MoS2 nanosheets for various applications.
The stability of molybdenum disulfide nanosheets in air can be significantly enhanced by SnO2 nanocrystal decoration. The SnO2 nanocrystals act as strong p‐type dopants for molybdenum disulfide, leading to a change of the molybdenum disulfide nanosheets from n‐type to p‐type behavior. The nanohybrids exhibit high sensitivity, excellent selectivity, and repeatability to NO2 under a practical dry air environment.
Meeting the increasing demand for sensors with high sensitivity, high selectivity, and rapid detection presents many challenges. In the last decade, electronic sensors based on field-effect ...transistors (FETs) have been widely studied due to their high sensitivity, rapid detection, and simple test procedure. Among these sensors, two-dimensional (2D) nanomaterial-based FET sensors have been demonstrated with tremendous potential for the detection of a wide range of analytes which is attributed to the unique structural and electronic properties of 2D nanomaterials. This comprehensive review discusses the recent progress in graphene-, 2D transition metal dichalcogenide-, and 2D black phosphorus-based FET sensors, with an emphasis on rapid and low-concentration detection of gases, biomolecules, and water contaminants.
This review highlights the recent progress in graphene-, 2D transition metal dichalcogenide-, and 2D black phosphorus-based FET sensors for detecting gases, biomolecules, and water contaminants.
A novel hybrid electrocatalyst consisting of nitrogen‐doped graphene/cobalt‐embedded porous carbon polyhedron (N/Co‐doped PCP//NRGO) is prepared through simple pyrolysis of graphene oxide‐supported ...cobalt‐based zeolitic imidazolate‐frameworks. Remarkable features of the porous carbon structure, N/Co‐doping effect, introduction of NRGO, and good contact between N/Co‐doped PCP and NRGO result in a high catalytic efficiency. The hybrid shows excellent electrocatalytic activities and kinetics for oxygen reduction reaction in basic media, which compares favorably with those of the Pt/C catalyst, together with superior durability, a four‐electron pathway, and excellent methanol tolerance. The hybrid also exhibits superior performance for hydrogen evolution reaction, offering a low onset overpotential of 58 mV and a stable current density of 10 mA cm−2 at 229 mV in acid media, as well as good catalytic performance for oxygen evolution reaction (a small overpotential of 1.66 V for 10 mA cm−2 current density). The dual‐active‐site mechanism originating from synergic effects between N/Co‐doped PCP and NRGO is responsible for the excellent performance of the hybrid. This development offers an attractive catalyst material for large‐scale fuel cells and water splitting technologies.
A novel hybrid electrocatalyst consisting of nitrogen‐doped graphene/cobalt‐embedded porous carbon polyhedron (N/Co‐doped PCP//NRGO) is obtained through a simple pyrolysis of graphene oxide‐supported cobalt‐based zeolitic imidazolate‐frameworks. The hybrid exhibits excellent electrocatalytic activities for oxygen reduction, hydrogen evolution, and oxygen evolution reactions with good stability. The enhanced performance is correlated with the dual‐active‐site mechanism originating from synergic effects between N/Co‐doped PCP and NRGO sheets.
Nanocarbon-based gas sensors: progress and challenges Mao, Shun; Lu, Ganhua; Chen, Junhong
Journal of materials chemistry. A, Materials for energy and sustainability,
01/2014, Letnik:
2, Številka:
16
Journal Article
Recenzirano
Odprti dostop
Novel materials based on nanocarbons (e.g., carbon nanotubes (CNTs) and graphene) have attracted much attention as sensing elements in miniaturized, low-power consumption, and ubiquitous electronic ...gas sensors due to their unique structural and electronic properties. This highlight discusses some recent progress in the research on nanocarbon-based electronic gas sensors, including CNTs, graphene, and their composites (i.e., nanocarbon-nanocrystal hybrids), identifies the technological barriers that impair their commercialization, and presents an outlook of the challenges and opportunities for the use of nanocarbon-based materials in next generation gas sensors.
Electromagnetic (EM) interference pollution is a pressing issue with the rapid development of information technologies. To solve this problem, absorbing materials have attached arising attention ...these years. SiC has potential applications in military stealth and radar absorbing materials for its good absorbing property, broad absorbing frequency band, adjustable electrical property and low density. Moreover, the excellent properties at high temperatures including high chemistry stability, high strength, good corrosion and oxidation resistance make it a promising candidate as high-temperature and harsh-environment absorber. Notably, SiC nanowires (SiC NWs) can consume more microwaves than bulk SiC, because of one dimension (1D) structure, large specific surface area and high polarization loss. In this review, we focus on current research of SiC NWs absorbing materials. The absorbing mechanism of 1D SiC nanomaterials with different microstructures is also introduced. The major influence factors including defects, surface, network structure, thickness and temperature are further discussed. Meanwhile, we also propose the improved methods of SiC NWs absorbers, such as doping nanoparticles, introducing defects and forming the core-shell structure. Based on the improvements, 3D porous SiC NWs composite materials are extensively studied for their outstanding absorbing performance. Finally, the future prospects of SiC NWs absorbing materials are also proposed.
Display omitted
•Poperties and challenges of SiC nanowires (NWs) absorbing materials are indicated.•Microstructures and influence factors of SiC NWs absorbers are discussed in detail.•Research status and modifications of SiC NWs absorbing materials are proposed.•3D porous SiC NWs composite absorbing materials are highlighted.•Future prospect of SiC NWs absorbing materials is also proposed.
PDF
