rGO Hybrid Research Articles

Self-Enhanced Antibacterial and Antifouling Behavior of Three-Dimensional Porous Cu2O Nanoparticles Functionalized by an Organic-Inorganic Hybrid Matrix.

Cu2O is currently an important protective material for domestic engineering and equipment used to exploit marine resources. Cu+ is considered to have more effective antibacterial and antifouling activities than Cu2+. However, disproportionation of Cu+ in the natural environment leads to its reduced bioavailability and weakened reactivity. Novel and functionalized Cu2O composites could enable efficient and environmentally friendly applications of Cu+. To this end, a series of three-dimensional porous Cu2O nanoparticles (3DNP-Cu2O) functionalized by organic (redox gel, R-Gel)-inorganic (reduced graphene oxide, rGO) hybrids─3DNP-Cu2O/rGOx@R-Gel─at room temperature by immobilization-reduction method was prepared and applied for protection against marine biofouling. 3DNP-Cu2O/rGO1.76@R-Gel includes rGO and R-Gel shape 3D porous Cu2O nanoparticles with diameters ∼177 nm and strong dispersion and antioxidant stability. Compared with commercial Cu2O (Cu2O-0), 3DNP-Cu2O/rGO1.76@R-Gel exhibited an ∼50% higher bactericidal rate, ∼96.22% higher water content, and ∼75% lower adhesion of mussels and barnacles. Moreover, 3DNP-Cu2O/rGOx@R-Gel maintains the same excellent, stable, and long-lasting bactericidal performance as Cu2O-0@R-Gel while reducing the average copper ion release concentration by ∼56 to 76%. This was also confirmed by X-ray diffraction, X-ray photoelectric spectroscopy (XPS), atomic absorption spectroscopy, and antifouling tests. In addition, XPS tests of rGO-Cu2+ and R-Gel-Cu2+, photocurrent tests of 3DNP-Cu2O/rGO1.76@R-Gel, and energy-dispersive spectrometry pictures of bacteria confirm that R-Gel and rGO act as electron donors and transfer substrates driving the reduction of Cu2+ (Cu2+ → Cu+) and the diffusion of Cu+. Thus, a self-growing antibacterial and antifouling system of 3DNP-Cu2O/rGO1.76@R-Gel was achieved. The mechanism of accelerated bacterial inactivation and resistance to mussel and barnacle adhesion by 3DNP-Cu2O/rGO1.76@R-Gel was interpreted. It is shown that rGO and R-Gel are important players in the antibacterial and antifouling system of 3DNP-Cu2O/rGO1.76@R-Gel.

Electrical and photoelectric properties of hybrid structures based on reduced graphene oxide and Pd-doped porous silicon

This study suggests the Pd-doped porous silicon (PS)–reduced graphene oxide (rGO) hybrid structures to create a photosensitive field-effect transistor. I-V curves and switching characteristics of the created graphene field-effect transistors were analyzed. A significant effect of the supporting porous layer on the transfer of charge carriers in the graphene film was established. A decrease in internal resistance and an increase in the capacitance of the hybrid structures due to photogenerated charge carriers were found. The parameters of the equivalent circuit model of the Pd-doped PS–rGO under the influence of irradiation were determined based on the impedance spectra.

Three-dimensional CNT-rGO/PDMS porous scaffold derived supercompressible lightweight body-mounted piezoresistive force sensor for human motion monitoring

Wearable electronics is an emerging field that demands composites with both reliable mechanical durability and suitable electrical sensitivity. Herein, we report a combination of supercompressible, ultralightweight, piezoresistive and mechanically robust sensor created by the infiltration of active fillers (CNTs/rGO) on the 3D porous scaffold of PDMS. Carbon nanotubes (CNTs) and reduced graphene oxide (rGO) hybrid synergistically improve the electrical and sensing properties by providing better interfacial contacts, high electron/phonon transfer; low inter tube slippage and reduction in phonon scattering. This study provides useful insights and experimental optimisation of parameters like dropping time and nanofiller concentrations to generate highly viable hybrid microstructure for sensor applications. The sensor shows excellent peizoresistive performance like wide linearity range, large-scale force sensing, supercompressibility, good durability, rapid response-recovery time and good sensitivity. The multifunctional sensor exhibits promising potential for the real-time monitoring of human flexion, like joint movements of finger, wrist, elbow and knee. It can directly be integrated on a shoe sole for reliable real-time gait monitoring. The smart insole could accurately monitor and distinguish gait phase while walking, jogging, squatting, sitting, standing. Based on the versatility of the sensor and the ability to accurately evaluate gait speed, stride length the sensor can be employed for bio-motion analysis, myoelectric prosthesis and other wearable devices.

One-Step Microwave-Assisted Hydrothermal Preparation of Zn-ZnO(Nw)-rGO Electrodes for Supercapacitor Applications.

Zn-ZnO(Nw)-rGO hybrid electrodes for supercapacitor applications were successfully prepared in situ by a one-step microwave-assisted hydrothermal method by deposition of reduced graphene oxide (rGO) on the structure of ZnO nanowires grown on the Zn foil. During the hydrothermal treatment, two processes occur the reduction of graphene oxide (GO) and the deposition of rGO on the Zn-ZnO(Nw) support. The growth of ZnO nanowires was achieved by thermal oxidation below the melting point of the Zn foil in a controlled atmosphere. The as-obtained electrodes were assessed for structural, optical, and morphological properties by X-ray diffraction, Raman spectroscopy, ultraviolet-visible spectroscopy, SEM microscopy, and EDX analysis. The supercapacitor properties of the Zn-ZnO(Nw)-rGO hybrid electrodes were investigated by cyclic voltammetry, electrochemical impedance spectroscopy, and galvanostatic charge-discharge analysis. The CV curve reveals that the Zn-ZnO(Nw)-rGO hybrid structures work as negative electrodes and exhibit a non-ideal rectangle-like shape, suggesting that the as-synthesized structure behaves as a pseudo-capacitor. A maximum capacitance was determined to be 395.79 mF cm-2 at a scan rate of 5 mV s-1. Based on GCD analysis, the maximum specific capacitance of 145.59 mF cm-2 was achieved at a low power density of 2 mA cm-2. The cycle life assessment of the Zn-ZnO(Nw)-rGO hybrid electrode over a 250-cycle number was performed by CV and GCD analysis. The maximum retention rate of 120.86% was achieved from GCD analysis over 250 cycles for the Zn-ZnO(Nw)-rGO hybrid electrode.

Characteristics and Electrochemical Performance of Hydroxyl-Functionalized Graphene Quantum Dot-Coated Si Nanoparticles/Reduced Graphene Hybrid Anodes for Advanced Li-Ion Batteries

By powering sophisticated lithium-ion batteries (LIBs), silicon/carbon (Si/C) composites have the potential to accelerate the sustainable energy transition. This is a first-of-its-kind Si/C hybrid with hydroxyl-functionalized graphene quantum dots (OH-GQD) electrostatically assembled within interconnected reduced graphene oxide networks (OH-GQD@Si/rGO) prepared through solution-phase ultrasonication and subsequent one-step, low-temperature annealing and thermal reduction. The OH-GQD@Si/rGO hybrid utilized as the LIB anode delivered a high initial specific capacity of 2,229.16, 1,303.21, and 1,090.13 mAh g−1 reversible capacities at 100 mA g−1 after 50 and 100 cycles, and recovered 1,473.28 mAh g−1 at rates as high as 5 A g−1. The synergistic benefits of the OH-GQD/rGO interface give dual, conductive carbon protection to silicon nanoparticles. Consecutive Si surface modifications improved Si–rGO contact modes. The initial OH-GQD carbon coating increased storage capacity through vacancy defects changing the electron density in the lattice, whereas hydroxyl functionality at the edges acted as active storage sites. Secondary protection through rGO encapsulation improved Si conductivity and usage by providing continuous electron/ion routes while minimizing Si volume variations. The proposed OH-GQD/rGO hybridization as a dual-carbon protection strategy to Si stabilized the solid electrolyte interface leading to electrode stability. This work is expected to advance the development of next-generation Si-based LIB anodes.

Cation-deficient T-Nb2O5/graphene Hybrids synthesized via chemical oxidative etching of MXene for advanced lithium-ion capacitors

Orthorhombic niobium pentoxide (T-Nb2O5) is widely acknowledged as a fast pseudocapacitive material. Nevertheless, its application is hindered by the narrow voltage window (1–3 V vs. Li/Li+) that arises from irreversible phase transformation and sluggish kinetics during deep lithiation. Herein, we demonstrate a unique method for introducing Nb vacancies in T-Nb2O5 nanoparticles via amine-assisted oxidative etching of Nb2CTx MXene, providing extra storage sites and improving structural flexibility by introducing cationic defects. Subsequently reduced graphene oxide (rGO) is employed as substrate to disperse T-Nb2O5 nanoparticles and construct T-Nb2O5/rGO nanohybrids. Multiple characterizations and computational simulations demonstrate that the resulting T-Nb2O5/rGO hybrid anode exhibits rapid and stable multi-electron transfer lithium storage. Owing to the enrichment of Nb vacancies and nanoparticle morphology, even when voltage window of 0.01–3 V (vs. Li/Li+) is extended, T-Nb2O5 exhibits a pseudocapacitive mechanism and integrity of partial crystal structure; effectively tackling the structural collapse and sluggish kinetics of T-Nb2O5. Consequently, the T-Nb2O5/rGO anode shows a superior rate capacity (148 mAh/g at 10 A/g) and cycling stability (3000 cycles at 5 A/g). Remarkably, the assembled lithium-ion capacitors achieve a high energy density of 123.7 Wh/kg, a power density of 22.5 kW/kg, and a capacity retention of 83.6% after 20,000 cycles.

Experimental and computational investigation on the charge storage performance of a novel Al2O3-reduced graphene oxide hybrid electrode

The advancements in electrochemical capacitors have noticed a remarkable enhancement in the performance for smart electronic device applications, which has led to the invention of novel and low-cost electroactive materials. Herein, we synthesized nanostructured Al2O3 and Al2O3-reduced graphene oxide (Al2O3-rGO) hybrid through hydrothermal and post-hydrothermal calcination processes. The synthesized materials were subject to standard characterisation processes to verify their morphological and structural details. The electrochemical performances of nanostructured Al2O3 and Al2O3- rGO hybrid were evaluated through computational and experimental analyses. Due to the superior electrical conductivity of reduced graphene oxide and the synergistic effect of both EDLC and pseudocapacitive behaviour, the Al2O3- rGO hybrid shows much improved electrochemical performance (~ 15-fold) as compared to bare Al2O3. Further, a symmetric supercapacitor device (SSD) was designed using the Al2O3- rGO hybrid electrodes, and detailed electrochemical performance was evaluated. The fabricated Al2O3- rGO hybrid-based SSD showed 98.56% capacity retention when subjected to ~ 10,000 charge–discharge cycles. Both the systems (Al2O3 and its rGO hybrid) have been analysed extensively with the help of Density Functional Theory simulation technique to provide detailed structural and electronic properties. With the introduction of reduced graphene oxide, the available electronic states near the Fermi level are greatly enhanced, imparting a significant increment in the conductivity of the hybrid system. The lower diffusion energy barrier for electrolyte ions and higher quantum capacitance for the hybrid structure compared to pristine Al2O3 justify improvement in charge storage performance for the hybrid structure, supporting our experimental findings.

Enhanced Electrochemical Ethanol Sensitivity on Ni/NiO‐rGO Hybrids Nanostructures at Room Temperature

AbstractHerein, we depict that the consequential nickel/nickel oxide‐reduced graphene oxide (Ni/NiO‐rGO) hybrid materials synthesized by sol‐gel approach can give as competent electrocatalyst for oxidative determination of ethanol in alkaline condition. Ni/NiO‐rGO based electrochemical sensor shows rapid and highly sensitive linear sweep voltametric (LSV) response to ethanol at an ultra‐low oxidation potential of 0.33 V vs. SCE. Moreover, the electrochemical sensor demonstrates highly stable (current and potential) also with low charge transfer resistance confirmed from chronoamperometic (i‐t) and electrochemical impedance spectroscopic (EIS) data respectively towards ethanol oxidation at Ni/NiO‐rGO hybrid interface confirms its acitivity over individuals i. e. Ni/NiO nanoparticles and rGO. Moreover, linear increase in current density upto 100 μM concentration of ethanol and for the scan rates in the range of 10–100 mV/s with positive shift in potential confirms ethanol oxidation is diffusion controlled process. The selective analysis of electrochemical response for ethanol in benadryl sample with same oxidation potential of ethanol beverages with enhanced ethanol oxidation potential for determination of ethanol concentration into benadryl sample analysis.

Effect of reduced graphene oxide hybridization on ZnO nanoparticles sensitivity to NO2 gas: A DFT study

In the present work, a density functional theory (DFT) calculation to simulate reduced graphene oxide (rGO) hybrid with zinc oxide (ZnO) nanoparticle's sensitivity to NO2 gas is performed. In comparison with the experiment, DFT calculations give acceptable results to available bond lengths, lattice parameters, X-ray photoelectron spectroscopy (XPS), energy gaps, Gibbs free energy, enthalpy, entropy, etc. to ZnO, rGO, and ZnO/rGO hybrid. ZnO and rGO show n-type and p-type semiconductor behavior, respectively. The formed p-n heterojunction between rGO and ZnO is of the staggering gap type. Results show that rGO increases the sensitivity of ZnO to NO2 gas as they form a hybrid. ZnO/rGO hybrid has a higher number of vacancies that can be used to attract oxygen atoms from NO2 and change the resistivity of the hybrid. The combined reduction of oxygen from NO2 and NO can give a very high value of the Gibbs free energy of reaction that explains the ppb level sensitivity of the ZnO/rGO hybrid. The dissociation of NO2 in the air reduces the sensitivity of the ZnO/rGO hybrid at temperatures higher than 300 ̊C.

Prussian blue analog-derived nickel iron phosphide-reduced graphene oxide hybrid as an efficient catalyst for overall water electrolysis

Efficient and bifunctional nonprecious catalysts for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) are essential for the production of green hydrogen via water electrolysis. Transition metal (Ni, Co, Fe, etc.) phosphides are frequently documented HER catalysts, whereas their bimetallic oxides are efficient OER catalysts, thus enabling bifunctional catalysis for water electrolysis via proper operation. Herein, phosphide-reduced graphene oxide (rGO) hybrids were prepared from graphene oxide (GO)-incorporated bimetal Prussian blue analog (PBA) precursors. The hybrids could experience partial surface oxidation to create oxide layers with OER activities, and the hybrids also possessed considerable HER properties, therefore enabling bifunctional catalytic features for water electrolysis. The typical NiFeP-rGO hybrid demonstrated an overpotential of 250 mV at 10 mA cm−2 and good durability for OER, as well as moderate HER catalytic features (overpotential of 165 mV at −10 mA cm−2 and acceptable catalytic stability). Due to the bifunctional catalytic features, the NiFeP-rGO-based symmetric water electrolyzer demonstrated a moderate input voltage and high faradaic efficiency (FE) for O2 and H2 production. The current work provides a feasible way to prepare OER and HER bifunctional catalysts by facile phosphorization of PBA-associated precursors and spontaneous surface oxidation. Given the oxidation/reduction bifunctional catalytic behaviors, phosphide-rGO hybrid catalysts have great potential for widespread application in fields beyond water electrolysis, such as electrochemical pollution abatement, sensors, energy devices and organic syntheses.

Elevating IrOx acidic oxygen evolution activity using SnO2-rGO hybrid support

• IrO x electrocatalysts on SnO 2 -rGO hybrid support for acidic OER were synthesized. • SnO 2 –rGO hybrid supports imparted active sites to the IrO x particles. • The OER activity of the catalysts was tuned by varying the Ir oxidation states. • IrO x on SnO 2 -rGO showed 10-fold higher mass activity than Ir black catalyst. Recently, Ir-based catalysts have been deposited onto high-surface-area and highly conductive materials to decrease noble metal loading in electrodes and thus increase the commercial viability of proton exchange membrane (PEM) water electrolyzers. carbon material supports impart active surface areas to the catalyst and metal-based supports enhance stability, thus improving the electrode performance for the energy-intensive and sluggish oxygen evolution reaction (OER). Herein, iridium oxide (IrO x ) electrocatalysts supported on a SnO 2 -reduced graphene oxide (rGO) composite (denoted as IrO x /SG) were used for the OER catalysis in acidic media. The effects of the SnO 2 –rGO hybrid support composition on the morphology, structure, surface composition, and performance of the IrO x catalyst were investigated. IrO x /SG catalysts were synthesized using ultrasonic spray pyrolysis and a modified polyol method. SnO 2 –rGO supports were employed to provide more anchoring sites for catalyst nanoparticle deposition and to modulate the catalytic activity and stability. Among the tested samples, the IrO x /S 80 G 20 catalyst (i.e., IrO x nanoparticles on 80 wt% SnO 2 and 20 wt% rGO support) showed the best OER performance. It exhibited a 10-fold higher mass activity than that of the commercial Ir black catalyst, which is possibly due to its high electrochemically active surface area (ECSA) and Ir 3+ ion and oxygen vacancy concentrations.

Porous 3D columnar-sphere of NiO nanomaterials synthesized for supercapacitors via hydrothermal route: impact of thiourea concentration.

The charge storage application has witnessed a dramatic increase in terms of the short charge-discharge time of supercapacitors, specifically in highly active electrode materials. For charge storage supercapacitor applications, highly porous materials are preferable. In this research article, thiourea acts as a leaving agent in the preparation of the porous 3D spherical architecture of NiO nanomaterials. The influence of the molar concentration of thiourea on structural, morphological, and electrochemical charge storage applications has been studied. X-ray diffraction reveals a cubic structure with Fm3̄m space group for the NiO nanomaterials. The scanning electron microscopy (SEM) images show the porous 3D columnar spherical structure, and FTIR has been used for the optical analysis of the NiO materials. The 1D-3D columnar-spherical structure of the NiO flakes exhibits a high electrochemical charge storage pseudocapacitive nature. The optimized 0.40 M thiourea-NiO (Th-NiO) nanomaterial is highly hydrophilic, exhibiting a maximum specific capacity of 171.1 mA h g-1 at 5 mV s-1 by CV and 148.5 mA h g-1 at 0.2 mA cm-2 by GCD. The highest power, energy densities are 0.96 kW kg-1 and 6.66 W h kg-1 with the highest charge-discharge cycle rating of 92% up to 5000 cycles of the asymmetric NiO//rGO hybrid supercapacitor device.

Enhanced room-temperature NO2 response of noble metal decorated α-Fe2O3/SnO2–rGO hybrids

Noble metal decorated α-Fe2O3/SnO2–rGO hybrids were synthesized. The obtained Pt modified α-Fe2O3/SnO2–rGO hybrids show the highest response value of 21.3 toward 1 ppm NO2 at room temperature, which is competitive among the NO2 sensors.

Fabrication of Flexible Thermoplastic Polyurethane/Coal Hydrogasification Semi-coke Composites with Low rGO Content for High-Performance Microwave Absorption

Semi-coke (SC), a residue of coal hydrogasification, is recycled and incorporated into thermoplastic polyurethane (TPU) to create composites for microwave absorption (MA). Herein, we developed porous reduced SC (rSC)–reduced graphene oxide (rGO) hybrids (SGHs) via in situ reduction of a preoxidized SC (oSC) and graphene oxide (GO) mixture. Low-content GO was introduced to considerably improve the dielectric properties of SGHs while decreasing the production cost. Then, a solution blending technique was applied to develop microwave absorbers using TPU as the matrix. The obtained TPU/SGH5 composite with a feed ratio of 5:1 (oSC:GO) showed an optimum reflection loss of −48.81 dB at a thickness of 2.5 mm and an effective absorption bandwidth of 4.30 GHz (7.74–12.04 GHz) in 2–18 GHz. However, the MA property of the obtained composites with the same amount of rSC or rGO alone was not comparable to that of the TPU/SGH5 composite. The inherent magnetism, heteroatoms, and abundance of heterogeneous surfaces of rSC and the considerable dielectric loss of rGO worked together to improve the MA performance of TPU/SGH composites. This study offers an easy and effective technical method for producing high-performance microwave absorbers with a low rGO content, illuminating the path toward achieving sustainable development by converting waste into wealth.

Suppressed Layered-to-Spinel Phase Transition in δ-MnO2 via van der Waals Interaction for Highly Stable Zn/MnO2 Batteries.

Although birnessite-type manganese dioxide (δ-MnO2 ) with a large interlayer spacing (≈7 Å) is a promising cathode candidate for aqueous Zn/MnO2 batteries, the poor structural stability associated with Zn2+ intercalation/deintercalation limits its further practical application. Herein, δ-MnO2 ultrathin nanosheets are coupled with reduced graphene oxide (rGO) via van der Waals (vdW) self-assembly in a vacuum freeze-drying process. It is interesting to find that the presence of vdW interaction between δ-MnO2 and rGO can effectively suppress the layered-to-spinel phase transition in δ-MnO2 during cycling. As a result, the coupled δ-MnO2 /rGO hybrid cathode with a sandwich-like heterostructure exhibits remarkable cycle performance with 80.1% capacity retained after 3000 cycles at 2.0 A g-1 . The first principle calculations demonstrate that the strong interfacial interaction between δ-MnO2 and rGO results in improved electron transfer and strengthened layered structure for δ-MnO2 . This work establishes a viable strategy to mitigate the adverse layered-to-spinel phase transition in layered manganese oxide in aqueous energy storage systems.

Gamma radiation induced synthesis of Ag decorated NiMn2O4 nanoplates with enhanced electrochemical performance for asymmetric supercapacitor

Herein, gamma radiation was used to assist the synthesis of Ag decorated nanoplates spinel-type oxide NiMn2O4 as a prospective electrode for supercapacitors. In addition to accelerating charge transfer, Ag nanoparticles provide a minor extent of pseudocapacitance. When evaluated in an aqueous KOH electrolyte, the Ag@NiMn2O4 electrode displays a capacitance of 622 Fg−1 at the current density of 1 A g−1 while retaining exceptional cycle stability (capacitance retention of nearly 88.8 % and 97.6 % coulombic efficiency at 10 Ag−1 after 5000 cycles). Whereas an asymmetric supercapacitor (Ag@NiMn2O4//rGO) has been assembled, it has a maximum specific density of 30.44 Wh kg−1 with a specific power of 10.3006 kW kg−1 within a broad potential window of 1.6 V. Moreover, the capacitance of the Ag@NiMn2O4//rGO hybrid supercapacitor device retains roughly retention of 94.8 % and exhibited approximately 100 % coulombic efficiency. As a result, with its enormous capacitance, high specific density, and extended cycle stability, the Ag-decorated the spinel-type oxide NiMn2O4 nanoplates electrode is an auspicious nominee for supercapacitors applications.

Rational synthesis of reduced graphene oxide hybrid nanocomposite with iron tungstate for selective detection of epinephrine in biological fluids

Hybrid nanocomposites made from metal tungstate and stacked graphene nanosheets have attracted the curiosity of researchers due to their high conductivity, strong electrochemical activity, and quick electrochemical transfer response. These properties prompted us to employ co-precipitation and sonochemical approaches to create low-cost iron tungstate (FeWO4)/reduced graphene oxide (rGO) hybrid material. The as-synthesized FeWO4/rGO nanocomposites (NCs) were evaluated for their physicochemical properties and structural and morphological aspects. A modified electrode composed of FeWO4/rGO NCs was utilized to detect epinephrine (Eph), a significant neurotransmitter and hormone associated with various human activities. The electrochemical behavior of Eph was quantified using cyclic voltammetry, and differential pulse voltammetry (DPV) on a FeWO4/rGO NCs modified electrode. According to the DPV study, Eph concentration was linearly distributed from 0.05 to 990.5 µM. For determining Eph, the sensor had a detection limit of 0.0073 µM and a sensitivity of 5.857 µAµM−1 cm−2. The sensor displayed excellent recovery results for the determination of Eph in the human urine and epinephrine pills real samples, revealing its excellent practicality.

Multifunctional elastic rGO hybrid aerogels for microwave absorption, infrared stealth and heat insulation

The application of advanced radar and infrared detection technology promotes the development of microwave-infrared compatible stealth technology, but also poses great challenges. Especially for the new generation of stealth fighters, how to facilely prepare a lightweight stealth material in both microwave and infrared is urgent. Herein, hierarchically porous reduced graphene oxide (rGO)/graphene oxide nanoribbon (GONR) aerogels (GG) with excellent stealth properties were prepared through green reduction and pyrolysis of the gel formed by GO and GONR. Remarkably, the aerogel (0.008 g/cm3) shows strongest yet broadest electromagnetic absorption when the percentage of GO and GONR is equal (GG33). Its effective absorption bandwidth (EAB) achieves 8.45 GHz and RL is up to −63.52 dB measured by coaxial method. In addition, the plane of GG33 exhibits a broad EAB of 8.52 GHz verified by the arch method. These are mainly attributed to the optimal impedance matching characteristics and increased polarization centers. Moreover, the porous structure formed by the rGO adsorbed with GONR ensures its eminent thermal insulation (less than 0.06 Wm/K), which is the key to infrared stealth. Interestingly, GG aerogels display great elasticity with reversible compressibility, fatigue resistance (100 % recovery after 1000th cycles under 30 % strain), and compression resistance sensitivity. In short, these excellent properties make ultra-lightweight multifunctional aerogels promising for various applications such as microwave-infrared compatible stealth aircrafts and portable electronic devices.

Three dimensional Ti3C2Tx and rGO hybrid supported Pt catalyst for the high performance hydrogen evolution reaction

The effective electrocatalysts for hydrogen evolution reaction (HER) in alkaline aqueous is critical point to reduce energy losses for water electrolysis. Here, a highly active and stable electrochemical catalyst of platinum (Pt) nanoparticles loaded on three-dimensional Ti3C2Tx-reduced graphite oxide (rGO) hybrid support (Pt/Ti3C2Tx-rGO3D) has been developed for hydrogen evolution reaction (HER). The large surface of 3 D support provides an adequate site for deposition of Pt nanoparticles, leading to superior HER activity with low overpotential about 41 mV and better stability than Pt/C. This study offers a hybrid support for the development of highly active electrocatalysts for hydrogen evolution reaction.

In-situ sulfidation-derived three-dimensional cobalt sulfide nanoflower/graphene nanosheet hybrid for ultrasensitive room-temperature NO2 gas sensor

Two-dimensional (2D) nanosheets show great potential for gas sensing, but they can hinder the penetration of gas molecules and lead to deteriorated sensing performances. Hence, construction of 2D nanosheet-based gas sensing materials with unique structures is desirable for high-performance gas sensing. Herein, a three-dimensional (3D) binary nanosheet heterostructure based on 3D cobalt sulfide (CoS) nanoflower/graphene nanosheet hybrid was constructed for room-temperature NO2 gas sensing. The 3D CoS/reduced graphene oxide (rGO) hybrid derived from a mixture of Co3O4 nanoflowers and graphene oxide nanosheets was facilely formed via in-situ sulfidation and reduction processes. The resistance response of as-assembled gas sensor based on 3D CoS nanoflower/graphene nanosheet hybrid to 1 ppm NO2 was 39.7%, which was 4.2 and 3.1 times higher than that of CoS and rGO sensors, respectively. A response as high as 10.5% was achieved even when the device was exposed to NO2 gas with a low concentration of 50 ppb. Furthermore, the hybrid device exhibited linear response characteristic, high selectivity, good repeatability, as well as long-term stability. Overall, the proposed design strategy together with the as-constructed structures can pave the way for the development of high-performance gas sensors based on graphene hybrids.