<i>In situ</i> growth and pyrolysis synthesis of super-hydrophobic graphene aerogels embedded with ultrafine β-Co nanocrystals for microwave absorption

Xu, Dongwei; Li, Jialiang; Chen, Ping; Qi, Yu; Wang, Jing; Yang, Sen; Guo, Xiang

doi:10.1039/c9tc00294d

Cited by 42 publications

(12 citation statements)

References 52 publications

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“…The peaks located at around 1,341 and 1,594 cm −1 are assigned to the typical D band and G band of rGO, respectively, . The intensity ratio of D peak to G peak (I D /I G ) of SnO 2 /rGO (1.12) is higher than that of GO (0.81), which indicates that the oxygen functional groups (e.g., C-O, O-C O, and O-C(O)-O) have been removed and induced defects during the synthesis process (Tuan, et al, 2018;Hu, et al, 2017;Xu, et al, 2019). The EDS analysis (Figure 1C) shows that the product contained C, O, Sn elements.…”

Section: Materials Characterizationsmentioning

confidence: 99%

“…The as-fabricated SnO 2 /rGO composites by this sol-gel method have high porosity and high surface roughness (Lin, et al, 2011). Meanwhile, the high anneal temperature (600°C) during carbonized process vastly decreases the hydrophilic oxygen-containing function groups on the rGO surface (e.g., C-O, O-C O, and O-C(O)-O), which can decrease the surface energy of SnO 2 /rGO composites and form a superhydrophobic surface (Wu, et al, 2018;Xu, et al, 2019;Cao, et al, 2019). The performance of humidity insensitivity of the NO 2 sensor may be weakened by working temperature (116°C) in some extent.…”

Section: Gas Sensing Performancesmentioning

confidence: 99%

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Humidity-Insensitive NO2 Sensors Based on SnO2/rGO Composites

et al. 2021

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This study reported a novel humidity-insensitive nitrogen dioxide (NO2) gas sensor based on tin dioxide (SnO2)/reduced graphene oxide (rGO) composites through the sol-gel method. The sensor demonstrated ppb-level NO2 detection in p-type sensing behaviors (13.6% response to 750 ppb). Because of the synergistic effect on SnO2/rGO p-n heterojunction, the sensing performance was greatly enhanced compared to that of bare rGO. The limit of detection of sensors was as low as 6.7 ppb under dry air. Moreover, benefited from the formed superhydrophobic structure of the SnO2/rGO composites (contact angle: 149.0°), the humidity showed a negligible influence on the dynamic response (Sg) of the sensor to different concentration of NO2 when increasing the relative humidity (RH) from 0 to 70% at 116°C. The relative conductivity of the sensor to 83% relative humidity was 0.11%. In addition, the response ratio (Sg/SRH) between 750 ppb NO2 and 83% RH was 649.0, indicating the negligible impaction of high-level ambient humidity on the sensor. The as-fabricated humidity-insensitive gas sensor can promise NO2 detection in real-world applications such as safety alarm, chemical engineering, and so on.

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Section: Materials Characterizationsmentioning

confidence: 99%

Section: Gas Sensing Performancesmentioning

confidence: 99%

Humidity-Insensitive NO2 Sensors Based on SnO2/rGO Composites

et al. 2021

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“…Composites of GAs can be prepared by which the desired properties of guest molecules along with GAs can be combined in a single physical entity. Various nanoarchitectures and polymers were generated in situ within GAs such as CoFe 2 O 4 nanoclusters [ 46 ], TiO 2 [ 47 ], and Co [ 48 ] nanocrystals, gold nanoparticles [ 49 ], Fe 3 O 4 nanoparticles [ 50 ], and quantum dots [ 51 ], along with some polymers such as polydimethylsiloxane [ 52 ], poly(aniline), poly(pyrrole) [ 34 , 53 ], and so on.…”

Section: Introductionmentioning

confidence: 99%

Graphene Aerogels for In Situ Synthesis of Conductive Poly(para-phenylenediamine) Polymers, and Their Sensor Application

2020

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In this study, macroporous graphene aerogels (GAs) were synthesized by chemical reduction of graphene oxide sheets and were used as a support material for in situ synthesis of conductive poly(para-phenylenediamine) (p(p-PDA)). The in situ synthesis of p(p-PDA) in GA was carried out by using a simple oxidation polymerization technique. Moreover, the prepared conductive p(p-PDA) polymers in the networks of GAs were doped with various types of acids such as hydrochloric acid (HCl), nitric acid (HNO3), sulfuric acid (H2SO4), phosphoric acid (H3PO4), respectively. The prepared GA and different acid-doped forms as GA/p(p-PDA) composites were characterized by FT-IR, TGA, and conductivity measurements. The observed FT-IR peaks at 1574 cm−1, and 1491 cm−1, for stretching deformations of quinone and benzene, respectively, confirmed the in situ synthesis of P(p-PDA) polymers within GAs. The conductivity of GAs with 2.17 × 10−4 ± 3.15 × 10−5 S·cm−1 has experienced an approximately 250-fold increase to 5.16 × 10−2 ± 2.72 × 10−3 S·cm−1 after in situ synthesis of p(p-PDA) polymers and with HCl doping. Conductivity values for different types of acid-doped GA/p(p-PDA) composites were compared with the bare p(p-PDA) and their undoped forms. Moreover, the changes in the conductivity of GA and GA/p(p-PDA) composites upon CO2 gas exposure were compared and their sensory potential in terms of response and sensitivity, along with reusability in CO2 detection, were evaluated.

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“…Nowadays, with the rapid development of the radar technology, wearable electronic products and wireless communication, the electromagnetic radiation and interface have already caused serious electromagnetic pollution, as well as military stealth technology. [1][2][3][4][5] Despite numerous works have focused on electromagnetic interface (EMI) shielding materials, the ideal EMI shielding materials with lightweight, high flexibility, thermally and chemically stable with high-efficiency over a broad absorption frequency range are still deemed for engineering. [6][7][8] To achieve such ideal goal, the electromagnetic wave consumed by dielectric loss, magnetic loss and other energy loss mechanisms should be further enhanced.…”

Section: Introductionmentioning

confidence: 99%

Enhanced electromagnetic wave absorption of Fe‐doped silicon oxycarbide nanocomposites

Qian

et al. 2019

J Am Ceram Soc

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Polymer‐derived ceramics (PDCs), such as SiOC, SiCN, SiBCN, and SiC are considered the best candidates for designing high‐performance microwave absorber due to their controllable structure, homogeneous element composition at atom level, tunable electromagnetic and electrochemical properties. Herein, Fe ions doped silicon oxycarbide (Fe ions‐SiOC) ceramics have been successfully fabricated via solvothermal method. The electromagnetic absorption performances of the nanocomposites prove to be controllable via tailoring Fe ion contents. The Fe ions effectively enhance both the interfacial polarization of amorphous SiOC, and the dielectric properties of the nanocomposites but barely effect magnetic properties of the nanocomposite. As for 0.16 mol/L‐SiOC ceramics annealed at 1450°C, the effective absorption bandwidth as high as 2.00 GHz and reflection loss of −59.60 dB at 5.40 GHz with the thickness of 4.55 mm are obtained. Such work opens up a novel and simple route to scale up the PDC‐based materials with broadband and excellent microwave absorbing performances.

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In situ growth and pyrolysis synthesis of super-hydrophobic graphene aerogels embedded with ultrafine β-Co nanocrystals for microwave absorption

Abstract: High-performance, lightweight, and broadband microwave absorption materials have drawn significant research focus.

Cited by 42 publications

References 52 publications

Humidity-Insensitive NO2 Sensors Based on SnO2/rGO Composites

Humidity-Insensitive NO2 Sensors Based on SnO2/rGO Composites

Graphene Aerogels for In Situ Synthesis of Conductive Poly(para-phenylenediamine) Polymers, and Their Sensor Application

Enhanced electromagnetic wave absorption of Fe‐doped silicon oxycarbide nanocomposites

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