Hydrazine Sensor Based on Co₃O₄/rGO/Carbon Cloth Electrochemical Electrode

Abstract

However, the electrochemical oxidation of hydrazine at glassy carbon electrode or bare metal is restricted by the high overpotential and sluggish kinetics, which generates a poor detection performance. [ 11 ] Although, lots of materials (such as zinc oxide nanonails, [ 12 ] ZnO nanorods, [ 13 ] polypyrrole nanoplates, [ 14 ] etc.) have been used in electrochemical sensors, exploring an effi cient and sensitive electrode material is of vital importance.In the past few decades, carbon-based composites, such as epoxy/carbon fi ber, [ 15 ] MnO 2 /graphene, [ 16 ] graphene oxide (GO)/ Fe, [ 17 ] MHTiO 2 @C-Au, [ 18 ] and Ni(OH) 2 /3D graphene, [ 19 ] have attracted tremendous interests owning to their unique physical and chemical properties. Specially, carbon cloth (CC) composites, consisting of reinforcing carbon fi bers and functional nanomaterials, are widely used in microwave absorption, [ 20 ] catalysis, [ 21,22 ] and supercapacitors, [ 23,24 ] due to its excellent mechanical strength, good corrosion resistance, high electrical conductivity, excellent fl exibility, and low-cost. However, to our knowledge, the application of carbon cloth in preparing freestanding electrode materials for electrochemical detection devices for hydrazine detection has never been reported.In this work, porous Co 3 O 4 nanosheets, vertically deposited onto the surface of graphene oxide modifi ed carbon cloth, were synthesized through a facile diffusion method at room temperature without the existence of any auxiliary reagents following a thermal annealing process (See Figure 1 ). The GO nanosheets on the surface of CC make the CC present hydrophilic and provide amounts of reactive oxygen functional groups. [ 25 ] Furthermore, the GO reduced at high temperature can greatly enhance the conductivity of CC. Compared with the previously reported method of dealing with nitric acid, [ 26 ] modifi ed CC with GO was simple and environmental friendliness. More importantly, the constructed Co 3 O 4 /reduced graphene oxide (rGO)/CC electrode demonstrates high sensitivity, low limit of detection (LOD), and excellent selectivity for hydrazine detection. Results and Discussion Structure and Morphology

Millimeter‐Long Vertically Aligned Carbon‐Nanotube‐ Supported Co3O4 Composite Electrode for High‐Performance Asymmetric Supercapacitor

“…Compared with pristine VACNTs, I D /I G ratio of the CVN composite increases obviously, indicating that the cobalt oxides might induce more structural defects or microstructural rearrangement to CNTs. Especially, three distinct peaks at 474, 510, and 675 cm −1 are identified for the CVN composites, which can be attributed to the E g , F 2g and A 1g vibration mode in Co 3 O 4 phase, respectively ,. Therefore, both the XRD and Raman analyses confirm the formation of Co 3 O 4 crystal on CNT surface.…”

“…Figure a shows XRD patterns of VACNTs and CVN composites annealed at different temperatures. In addition to the peaks from VACNTs, the diffraction peaks at 31.2°, 36.8°and 65.1° are indexed to the (220), (311), and (440) planes of Co 3 O 4 , respectively (JCPDS No.43‐1003) . Figure b presents Raman spectra of VACNTs and various CVN composites.…”

“…For all the composites, well‐defined broad redox peaks are observed, indicating that the electrochemical capacitance of the CVN electrode is mainly contributed by the pseudocapacitance of the Co 3 O 4 growing on CNTs. And the reversible Faradaic reactions can be expressed as follows, …”

Preparation of Electrode Materials Based on Carbon Cloth via Hydrothermal Method and Their Application in Supercapacitors

“…For three-dimensional composite materials with a controllable nanostructure based on CC, the most important thing is that they provide more active sites and exhibit excellent electrochemical properties [ 124 , 125 , 126 , 127 ]. We can see that metal composites exhibit oxidative performance, which is the advantage that other materials cannot achieve.…”

A Zero‐Power Optical, ppt‐ to ppm‐Level Toxic Gas and Vapor Sensor with Image, Text, and Analytical Capabilities

“…[10] Some gas sensors in the market are designed as badges and are potentially analytically accumulative but require the observer to distinguish color and color intensities. [11,12] To alleviate the potential drawbacks of current wearable sensors requiring battery power (based, for example, on metal oxide semiconductors, [13][14][15][16][17] electrochemical, [18][19][20][21][22][23][24] infrared, [25][26][27] photoionization detectors, [28,29] lasers, [30][31][32] among others) or recognizing a colorimetric read-out, a next generation sensor platform should not require either. One or some forms of color vision deficiency (color blindness) affects about one in twelve men (> 8%) and one in 200 women, [33,34] and men are the majority among emergency responders, military personnel, and firefighters.…”