Weight Ratio Of rGO Research Articles

ZnSe-rGO nanocomposites as photocatalysts for purification of textile dye contaminated water: A green approach to use wastewater for maize cultivation

Disputes about the probable availability of safe water and the efficacy of processed wastewater are key issues that necessitate a suitable solution to enhance the quality of clean water. The current research emphasizes the synthesis of ZnSe-reduced graphene oxide nanocomposites (ZnSe:rGO) with different weight ratios of rGO (represented as X = 0.6, 1 and 1.6 g)via one-step hydrothermal method. The photocatalytic performance for the degradation of methyl violet (MV) dye was investigated under visible light irradiation by varying the reaction parameters. The crystal structure, elemental composition, surface functionality and morphology of the synthesized ZnSe-XrGO nanocomposites were estimated by powder X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopic (SEM) techniques. UV–visible spectroscopy was used to investigate the optical properties. The highest efficiency is obtained for ZnSe-XrGO in 1:1 and it showed pseudo 1st order behavior with rate constant of 0.0167min−1and 94 % photodegradation of MV in just 3 h. Furthermore, hazardous effects of MV were investigated on the germination and growth of Zea mays seeds by giving them aqueous solution of MV (0, 8, 12, 24 and 48 ppm) and the decontaminated water after photodegradation of MV with the synthesized photoactive composite. The results showed profound negative effect on both germination and seedling growth at higher concentration (>12 ppm) of the dye solution. No hazardous effects were observed on both these parameters when it was given the dye degraded water which reflects the practical use of the synthesized catalyst for water remediation. The current study fulfills the goal of designing an efficient visible-light active nano-photocatalyst and its direct applicability on life sciences for water purification.

Pulsed laser ablation-mediated facile fabrication of MoO3/TiO2/rGO nanocomposite as a photocatalyst for dye degradation

In this work, for the first time, the MoO3/TiO2/rGO nanocomposites with different weight ratios of rGO (0%, 5%, 10%, and 20%) were fabricated using pulsed laser ablation technique. The as-fabricated nanocomposites were employed for photodegradation of Methylene Blue (MB) under UV light irradiation. The morphological, structural, and chemical properties of the fabricated photocatalysts were characterized using XRD, TEM, SEM, UV-DRS, XPS, FTIR, TGA, DSC, and PL. Comparative experimental studies displayed that MoO3/TiO2/rGO nanocomposites fabricated with 5% rGO showed the highest photocatalytic degradation (95%) of MB under UV irradiation. This superior photocatalytic performance could be ascribed to the narrow bandgap of the fabricated nanocomposites as well as the synergistic effect of the three components.

Investigations on structural, optical and electrical properties of microwave-assisted rGO:ZnO nanocomposite thin films

The reduced graphene oxide:Zinc oxide (rGO:ZnO) nanocomposite films were fabricated by an optimized wet-chemical sol–gel derived spin-coating method. A simple, fast and effective microwave-assisted approach was adopted for the reduction of the graphene oxide. The influence of rGO on the microstructural and optoelectronic properties of ZnO was studied by varying the weight ratios of rGO. The results showed significant changes in the microstructural and optoelectronic properties of the rGO:ZnO composite films. X-ray diffraction analysis confirmed the polycrystallinity of the composite films with a preferential growth orientation of the crystallites along (002) plane. Good optical transparency in the visible wavelength region was observed in all the composite films. As the weight percentage of rGO increased from 0% to 20%, the red shift of the absorption edge was noticed, indicating the weak Burstein-Moss effect. The optical bandgap of ZnO reduces as the amount of rGO increases, resulting in the reduction of transmittance in the composite thin films. The sheet resistance and therefore the resistivity of the composite films decreases with the loading of rGO into ZnO matrix. The lowest values of sheet resistance and resistivity, and the highest Figure of Merit have been recorded for 10% rGO:ZnO composite film. The obtained results illustrate that the 10% rGO:ZnO composite film could be a potential candidate for electrode applications.

Visible light-driven photocatalytic degradation of Rhodamine B dye onto TiO2/rGO nanocomposites

In the current study, a series of reduced graphene oxide coated titanium dioxide nanocomposites (TiO 2 /rGO) were fabricated via a simple hydrothermal synthetic route using graphite flakes and titanium (IV) oxysulfate - sulfuric acid hydrate as precursors for rGO and TiO 2 synthesis, respectively. The TiO 2 /rGO nanocomposites were fabricated with various weight ratios of rGO (5, 10, and 15%) and their photocatalytic activity against Rhodamine B (RhB) dye removal was investigated. The composition, optical activity, morphology, and porosity of the obtained nanomaterials were determined using different techniques, including X-ray diffraction (XRD), Field emission scanning electron microscopy (FE-SEM), Transmission electron microscopy (TEM), Brunauer-Emmett-Teller (BET), UV-Vis diffuse reflectance spectroscopy (DRS) and Raman spectroscopy. Hence the XRD results showed that the TiO 2 /rGO nanocomposites were successfully fabricated. The TEM images exhibited the efficient distribution of TiO 2 NPs on the rGO nanosheets. The significant structural changes in TiO 2 /rGO nanocomposites were reflected in the Raman spectra, indicating nanocomposite hybridization. The optical bandgap of the as-synthesized nanomaterials was slightly shifted from 3.14 eV (bare TiO 2 ) to 2.75 eV (TiO 2 /rGO 15%). Based on the photocatalytic degradation results, the best removal percentage of RhB dye was approached by TiO 2 /rGO (5%) at optimum conditions ([RhB]= 15 ppm, pH 9, catalyst dose= 1.2 g/L, and irradiation time= 120 min). The highly efficient TiO 2 /rGO (5%) nanocomposite showed enhanced photocatalytic behavior for the degradation of RhB dye, with a maximum removal percentage of (∼94.55%). Various reactive oxygen species (ROS) scavengers were employed to study the mechanism of photocatalytic degradation of RhB dye. The TiO 2 /rGO (5%) nanocomposite showed good cycling stability for five cycles. • The TiO 2 /rGO nanocomposites were fabricated with various weight ratios of rGO (5, 10, and 15%) • The morphological images exhibited the efficient distribution of TiO 2 NPs on the rGO nanosheets. • The UV-Vis spectra showed that the bandgap values of the nanocomposites decreased with increasing the concentration of the reduced graphene oxide. • The highly efficient TiO 2 /rGO (5%) nanocomposite showed enhanced photocatalytic behavior for the degradation of RhB dye, with a maximum removal percentage of (∼94.55%).

RGO nanosheet wrapped β-phase NiCu2S nanorods for advanced supercapacitor applications.

A new integration strategy of transition metal sulfide with carbon-based materials is used to boost its catalytic property and electrochemical performances in supercapacitor application. Herein, crystalline reduced graphene oxide (rGO) wrapped ternary metal sulfide nanorod composites with different rGO ratios are synthesized using hydrothermal technique and are compared for their physical, chemical, and electrochemical performances. It is found that their properties are tuned by the weight ratios of rGO. The electrochemical investigations reveal that β-NiCu2S/rGO nanocomposite electrode with 0.15 wt.% of rGO is found to possess maximum specific capacitance of 1583 F g-1 at current density of 15mAg-1 in aqueous electrolyte medium. The same electrode shows excellent cycling stability with capacitance retention of 89% after 5000 charging/discharging cycles. The reproducibility test performed on NiCu2S/rGO nanocomposite electrode with 0.15 wt.% of rGO indicates that it has high reproducible capacitive response and rate capability. Thus, the present work demonstrates that the β-NiCu2S/rGO nanocomposite can serve as a potential electrode material for developing supercapacitor energy storage system.

Impact of reduced graphene oxide on the sensing performance of Poly (3, 4–ethylenedioxythiophene) towards highly sensitive and selective CO sensor: A comprehensive study

Herein we tackled a rigorous study to extract the appropriate weight ratio of rGO incorporated with the PEDOT matrix that's led to optimal CO gas sensor performance. In this work, various ratios of reduced graphene oxide (rGO) have been incorporated into conjugated polymer poly (3, 4- ethylenedioxythiophene) (PEDOT) for comprehensively studying the influence of rGO on the sensing performance of PEDOT towards CO gas at room temperature. The pristine PEDOT and PEDOT/rGO nanocomposites were prepared by the in situ polymerization route. Among different weight ratios of PEDOT/rGO nanocomposites, the 30% PEDOT/rGO based-sensor demonstrated the highest response of 52% to CO gas, which is 3-fold higher than pure PEDOT response. The fabricated sensors showed a response to CO gas at a concentration range of (10–325 ppm) with a fast response/ recovery time of 55 s / 53 s, respectively. The outstanding sensing characteristics of our sensors are ascribed to the effect of high charge carrier, high surface area of rGO, and work function difference between rGO and PEDOT. Thus, in this work, the tested CO sensor has an innovative potentiality for practical applications.

Preparation and properties of reduced graphene oxide-carbon nanotubes aerogel/cotton flexible composite fabric with electromagnetic shielding function

The electromagnetic pollution has become a serious problem with the rapid development of electromagnetic industry. The present work prepared an electromagnetic interference (EMI) functional composite fabric. Reduced graphene oxide (rGO)-carbon nanotubes (CNTs) aerogel with three-dimensional (3-D) architecture were coated to the cotton fabric with the assistance of waterborne polyurethane (WPU). The structure of graphene aerogel was affected by the amount of CNTs. Small amount of CNTs is helpful to minish the pore size of aerogel and thus improve the EMI value. However, it has been shown that excess CNTs will destroy the 3-D architecture of graphene aerogel. Result shows that the EMI shielding effectiveness exceeded 35 dB when the weight ratio of rGO and CNTs was 7:3, and EMI value of the corresponding composite fabric samples reached 34 dB. Consequently, excellent EMI results were obtained by the unique 3-D rGO-CNTs aerogel in the case of a small nano-carbon material amount. The present work will be expected to make contributions to the practical application of rGO-CNTs aerogel.

Tunable nonlinear optical enhancement of α-FeOOH nanorods/RGO composites

High-quality α-FeOOH nanorods/reduced graphene oxide (RGO) composites were prepared by a facile hydrothermal method. Crystal structure and optical properties of the composites were characterized by XRD, SEM, TEM, FT-IR, Raman, UV–vis, PL. These results of characterization showed that the composites were successfully prepared. The third-order nonlinear optical (NLO) properties of the composites were investigated by Z-scan technique under 30 ps laser at 532 nm wavelength with 10 Hz repetition. The composites had larger third-order NLO susceptibility compared to pure α-FeOOH nanorods and RGO nanosheets. The enhancement of NLO performance benefited from synergistic effect of local field effect and charge transfer between α-FeOOH nanorods and RGO. Moreover, the composite with the α-FeOOH nanorods:RGO weight ratio of 2:1 (S3) showed the most robust NLO response. Comparing with RGO, the value of third-order NLO susceptibility χ(3) of S3 was increased by around 60 times and the saturation intensity Isat was nearly decreased by 6 times as the modulation depth M highly increased, respectively. The improved NLO property of α-FeOOH nanorods/RGO composite indicated its possible application in optical switches, mode lockers and other NLO devices.

Synthesis of Fe3O4/rGO@PANI with three-dimensional flower-like nanostructure and microwave absorption properties

Due to the pressing need for electromagnetic interference and radar stealth, microwave absorbers have garnered considerable attention. Through chemical co-precipitation and in-situ polymerization, we synthesize a ternary composite containing reduced graphene oxide, Fe3O4 with flower-like nanostructures, and polyaniline (PANI). To fine-tune the impedance matching and corrosion resistance of composite materials, the conductive PANI was densely coated on the surface of reduced graphene oxide (rGO)/flower-like Fe3O4(f-Fe3O4). The ternary composite exhibits excellent microwave absorption performance. In comparison to rGO/f-Fe3O4(1:10), which has a minimum reflection loss (RLmin) of −32.81 dB at 10.61 GHz and a 5.15 GHz effective absorption bandwidth (EAB) (7.34–12.49 GHz), rGO/f-Fe3O4(1:10)@PANI has an RLmin of −46.49 dB at 9.93 GHz with a 2.5 mm thickness and an EAB of 4.25 (8.90–13.15 GHz). The results indicate that the addition of the PANI anticorrosion coating layer has no discernible effect on the final microwave absorption performance. This article also examines the effect of rGO weight ratio on microwave absorbing properties. When the rGO content is too high, the impedance will be mismatched, while the too low rGO content will affect the absorbing performance. This research work has contributed to our present understanding of the structure design and composition control of microwave absorbers.

Binary TiO2/RGO photocatalyst for enhanced degradation of phenol and its application in underground coal gasification wastewater treatment

In this work, we synthesized the TiO2/reduced graphene oxide (TiO2/RGO) binary nanohybrids through the sol-anaerobic calcination method, the TiO2 nanoparticles belonging to anatase type were evenly loaded on RGO surface in the form of Ti–O–C bond. The enhanced photocatalytic performance can be ascribed to the existence of RGO that can effectively promote the transfer of photo-induced electron-hole pairs to generate more hydroxyl radicals (·OH) and superoxide anion (O2·-) degrading phenol. The TiO2/RGO nanocomposite with weight ratio of RGO to TiO2 (37.0%–55.7%) had achieved maximum degradation of phenol from aqueous solution, and about 97.87% of phenol had been removed within 180 min under UV-light illumination. Through GC-MS tracking of phenol degradation process, it can be observed that long-chain intermediates will be generated, and these intermediates will eventually be degraded, confirming that phenol can be completely removed. Additionally, around 67% TOC of simulated underground coal gasification (UCG) wastewater can be removed after 10 h degradation using TiO2/RGO binary composites as photocatalysts. All these results demonstrate that the binary nanohybrids possess great potential for the organic contaminants destruction from the actual coal chemical wastewater.

A superfine glass fibre air filter with rapid response to photocatalytic antibacterial properties under visible light by loading rGO/ZnO.

The development of high-performance air filter has become more and more important to public health. However, it has always been very challenging for developing a multifunctional air filter to simultaneously achieve excellent filtration and antibacterial properties. Herein, a versatile air filter was prepared with loading the reduced graphene (rGO) and zinc oxide on the superfine glass fibre (s-GF) with the three-dimensional network structure by in situ sol–gel process followed by calcination, which aims to achieve synergistic high-efficiency air filtration and rapid response to photocatalytic antibacterial properties under visible light. The air filter showed a three-dimensional network structure based on a rGO/ZnO/s-GF multilayer and exhibited the highest catalytic performance by achieving a 95% degradation effect on rhodamine B within 2 h and achieving 100% antibacterial inactivation of the Escherichia coli and Staphylococcus aureus within 4 h under visible light when the weight ratio of rGO in rGO/ZnO is 1.6%. The air filtration efficiency can also be maintained at 99% after loading ZnO and rGO photocatalytic particles. The spectrum of the photoluminescence (PL), UV-Vis diffuse reflectance spectra (DRS) and electron spin resonance (ESR) indicate that the combination of rGO and ZnO on the s-GF can increase the separation of photogenerated carriers and the specific surface area of the air filter, thereby increasing the photocatalytic response and antibacterial properties of the s-GF air filter under visible light in a short time.

Controlled assembly of nitrogen-doped iron carbide nanoparticles on reduced graphene oxide for electrochemical reduction of carbon dioxide to syngas

The electrocatalytic CO2 reduction reaction (CO2RR) decreases the amount of greenhouse gas in the atmosphere while enabling a closed carbon cycle. Herein, iron oleate was used as a precursor to produce oleic acid-coated triiron tetraoxide nanoparticles (Fe3O4@OA NPs) by pyrolysis, which was then assembled with reduced graphene oxide (rGO) and doped with dicyandiamide as a nitrogen source to obtain nitrogen-doped iron carbide nanoparticles assembled on rGO (N-Fe3C/rGO NPs). The catalyst prepared by nitrogen doping at 800 °C with an Fe3O4@OA NPs to rGO weight ratio of 20:1 showed good activity and stability for the CO2RR. At −0.3 to −0.4 V, the H2/CO ratio of the product from the catalyzed CO2RR was close to 2; thus, the product can be used for Fischer-Tropsch synthesis. The results of a series of experiments and X-ray photoelectron spectroscopy analysis showed that the synergy between the CN and FeN groups in the catalyst can promote the reduction of CO2 to CO. This work demonstrates a facile method for improving the catalytic reduction of CO2.

Binary TiO 2/RGO Photocatalyst for Enhanced Degradation of Phenol and its Application in Underground Coal Gasification Wastewater Treatment

In this work, we synthesize the TiO2/RGO binary nanohybrids through the sol-anaerobic calcination method, the TiO2 nanoparticles belonging to anatase type were evenly loaded on RGO surface in the form of Ti-O-C bond. The enhanced photocatalytic performance can be ascribed to the existence of RGO that can effectively promote the transfer of photo-induced electron-hole pairs to generate more hydroxyl radicals (·OH) and superoxide anion (O2·-) degrading phenol. The TiO2/RGO nanocomposite with weight ratio of RGO to TiO2 (37.0% to 55.7%) has achieved maximum degradation of phenol from aqueous solution, and about 97.87% of phenol has been removed within 180 min under UV-light illumination. Through GC-MS tracking of phenol degradation process, it can be observed that long-chain intermediates will be generated, and these intermediates will eventually be degraded, confirming that phenol can be completely removed. Additionally, around 67% TOC of simulated underground coal gasification (UCG) wastewater can be removed after 10 h degradation using TiO2/RGO binary composites as photocatalysts. All these results demonstrate that the binary nanohybrids possess great potential for the organic contaminants destruction from the actual coal chemical wastewater.

Dielectric properties and ac conductivity behavior of rGO incorporated PVP-PVA blended polymer nanocomposites films

We have reported dielectric and ac conductivity investigations on reduced grapheme oxide (rGO) incorporated PVP-PVA blend polymer nanocomposite films (BPNC) prepared via standard solution casting technique. The dielectric properties and ac conductivity have been explored using the complex electrochemical impedance technique that has been studied at room temperatures. The frequency-dependent dielectric constant (εʹ) is maximum at low frequencies region which value increases with increasing rGO concentration, while at higher frequency region their value decreases with increasing frequency for all BPNC films. The appearance of the loss tangent (tanδ) peaks at specific frequency suggested the existence of recline dipoles which has been found to shift towards high frequency side with increasing weight ratios of rGO in all the BPNC films. The fluctation of a.c conductivity behavior as a function of frequency follow Jonscher Power-law model. The a.c. conductivity shows an increasing trend with an increase in the doping concentration of rGO. The electrical modulus has been examined for supporting the complex permittivity part. The relaxation peaks occur in electric modulus (M“) indicates the presence of orientation dipoles in the blend polymer nanocomposites, which support the fast ion conduction.

RGO-ZnO nanocomposites as efficient photocatalyst for degradation of 4-BP and DEP using high temperature refluxing method in in-situ condition

Persistent organic pollutants (mainly aromatic compounds) such as bromophenol and diethyl phthalate are dangerous and act as primary contaminants in aqueous system. In this study, efficient reduced graphene oxide zinc oxide (rGO-ZnO) nanocomposites were synthesized by using a simple and facile method for photocatalytic degradation of 4-Bromophenol (4-BP) and diethyl phthalate (DEP). The rGO-ZnO (rGZ) nanocomposites (NCs) with different weight ratio of rGO and ZnO (coded as rGZ-1, rGZ-2, rGZ-5 and rGZ-10) were synthesized via high temperature refluxing method. The crystalline structure and phase, surface morphological study, optical properties, crystal defects and existence of functional groups in rGZ NCs were studied by X-ray diffraction (XRD), field-emission-scanning electron microscope (FE-SEM), UV-Visible diffuse reflectance spectroscopy (DRS), Raman spectroscopy and FT-IR analysis, respectively. The elimination of 4-BP and DEP from water by UV-light exposure was considered to estimate the photocatalytic efficiency of prepared rGZ NCs. The maximum elimination of 4-BP and DEP via photodegradation (advanced oxidation process) was found about 99.04% and 98.63% over rGZ NCs after 180 min UV irradiation, respectively. The photodegradation study was examined by using high performance liquid chromatography (HPLC) technique. This study confirms the efficient photocatalytic activity of rGZ-5 towards degradation of 4-BP and DEP. Finally, degradation mechanism has been proposed for the degradation of 4-BP and DEP.

Synergistic Effects of Hybrid Carbonaceous Fillers of Carbon Fibers and Reduced Graphene Oxides on Enhanced Heat-Dissipation Capability of Polymer Composites.

In this study, we investigated the synergistic effects of thermally conductive hybrid carbonaceous fillers of mesophase pitch-based carbon fibers (MPCFs) and reduced graphene oxides (rGOs) on the thermal conductivity of polymer matrix composites. Micro-sized MPCFs with different lengths (50 μm, 200 μm, and 6 mm) and nano-sized rGOs were used as the thermally conductive fillers used for the preparation of the heat-dissipation polymer composites. For all MPCF fillers with a different length, the thermal conductivity values of the MPCF/epoxy composites were proportional to the MPCF length and loading amount (0–50 wt%) of MPCFs. For an MPCF:rGO weight ratio of 49:1 (total loading amount of 50 wt%), the thermal conductivity values of MPCF-rGO/epoxy composites loaded with MPCFs of 50 μm, 200 μm, and 6 mm increased from 5.56 to 7.98 W/mK (approximately 44% increase), from 7.36 to 9.80 W/mK (approximately 33% increase), and from 11.53 to 12.58 W/mK (approximately 9% increase) compared to the MPCF/epoxy composites, respectively, indicating the synergistic effect on the thermal conductivity enhancement. The rGOs in the MPCF-rGO/epoxy composites acted as thermal bridges between neighboring MPCFs, resulting in the formation of effective heat transfer pathways. In contrast, the MPCF-rGO/epoxy composites with MPCF:rGO weight ratios of 48:2 and 47:3 decreased the synergistic effect more significantly compared to rGO content of 1 wt%, which is associated with the agglomeration of rGO nanoparticles. The synergistic effect was inversely proportional to the MPCF length. A theoretical approach, the modified Mori-Tanaka model, was used to estimate the thermal conductivity values of the MPCF-rGO/epoxy composites, which were in agreement with the experimentally measured values for MPCF-rGO/epoxy composites loaded with short MPCF lengths of 50 and 200 μm.

Morphology-dependent room temperature NO2 detection of CuO nanostructure/rGO composites

To study the effect of morphologies on the gas sensing behaviour, herein, we have synthesized three different CuO nanostructures, namely CuO nanobrick, CuO hierarchical flower-like and CuO nanochain. Hydrothermal method has been used to synthesize the CuO nanobrick and CuO hierarchical flower-like morphologies, whereas wet chemical method for CuO nanochain-like morphology. The present study reveals that all the CuO nanostructures-reduced graphene oxide (rGO) composite sensors show maximum response for NO2 gas at room temperature and intermediate humidity level (~ 50%RH). Furthermore, among all studied sensors, the CuO hierarchical flower-like/rGO sensor exhibits maximum NO2 gas-sensing response. At RT, the CuO hierarchical flower-like/rGO sensor shows response of ~ 58.1% in 30 s for 20 ppm NO2 which is ~ 1.7 times of CuO nanobrick/rGO sensor and almost twice of CuO nanochain/rGO composite sensor. Moreover, the gas sensing behaviours of composite samples synthesized with different weight (wt) ratios of rGO to CuO hierarchical flower-like for NO2 gas have also been studied to find optimum weight ratio of rGO and CuO hierarchical flower-like for which best sensing performance is observed. Consequently, CuO hierarchical flower-like with 25 wt% of rGO exhibits the highest response. All sensors show good reproducibility when tested for five successive cycles of 20 ppm NO2 and outstanding selectivity for NO2 gas. Furthermore, the sensing mechanism has been discussed in this paper by considering the role of morphology. Our work suggests that morphology of CuO and adding appropriate amount of rGO are crucial factors and influence the sensing behaviour of NO2 sensor.

Surface modification of tin oxide through reduced graphene oxide as a highly efficient cathode material for magnesium-ion batteries

Among post-lithium ion technologies, magnesium-ion batteries (MIBs) are receiving great concern in recent years. However, MIBs are mainly restrained by the lack of cathode materials, which may accommodate the fast diffusion kinetics of Mg2+ ions. To overcome this problem, herein we attempt to synthesize a reduced graphene oxide (rGO) encapsulated tin oxide (SnO2) nanoparticles composites through an electrostatic-interaction-induced-self-assembly approach at low temperature. The surface modification of SnO2 via carbonaceous coating enhanced the electrical conductivity of final composites. The SnO2-rGO composites with different weight ratios of rGO and SnO2 are employed as cathode material in magnesium-ion batteries. Experimental results show that MIB exhibits a maximum specific capacity of 222 mAhg−1 at the current density of 20 mAg−1 with a good cycle life (capacity retention of 90%). Unlike Li-ion batteries, no SnO2 nanoparticles expansion is observed during electrochemical cycling in all-phenyl-complex (APC) magnesium electrolytes, which ultimately improves the capacity retention. Furthermore, ex-situ x-ray diffraction and scanning electron microscopy (SEM) studies are used to understand the magnesiation/de-magnesiation mechanisms. At the end, SnO2-rGO composites are tested for Mg2+/Li+ hybrid ion batteries and results reveal a specific capacity of 350 mAhg−1 at the current density of 20 mAg−1. However, hybrid ion battery exhibited sharp decay in capacity owing to volume expansion of SnO2 based cathodes. This work will provide a new insight for synthesis of electrode materials for energy storage devices.

Degradation mechanisms of ofloxacin and cefazolin using peroxymonosulfate activated by reduced graphene oxide-CoFe2O4 composites

In this work, reduced graphene oxide (rGO) sheets were integrated with CoFe2O4 to construct distinctive composites that were evaluated as heterogeneous catalysts activating peroxymonosulfate (PMS) for the oxidative degradation of ofloxacin (OFX) and cefazolin (CFZ), two widely used pharmaceuticals belonging to the fluoroquinolone and β-lactam antibiotic families, respectively. The results showed that of all of the catalysts tested, the composite with an CoFe2O4 to rGO weight ratio of 20:2 (CFGO202) had the best reactivity, and achieved superior stability with negligible leaching of cobalt and iron under mild acidic conditions. Radical quenching experiments showed that the degradation of OFX was a radical-based oxidation process, while the decomposition and transformation of CFZ were largely due to PMS-induced direct oxidation via direct two-electron transfer. The near-complete degradation of OFX and CFZ could be attained under optimal conditions: pH 6.0, 0.1 g L−1 CFGO202 and 1 mM (for OFX) or 100 μM PMS (for CFZ). In comparison with OFX, the degradation of CFZ suffered less interference from the water matrix. An underlying mechanism was proposed based on the detection of radicals and X-ray photoelectron spectroscopy spectral data. Degradation intermediates were identified and the possible degradation pathways were proposed with the aid of density functional theory (DFT) calculations.

Reduced Graphene Oxide Heterostructured Silver Nanoparticles Significantly Enhanced Thermal Conductivities in Hot-Pressed Electrospun Polyimide Nanocomposites.

Graphene presents an extremely ultra-high thermal conductivity, well above other known thermally conductive fillers. However, graphene tends to aggregate easily due to its strong intermolecular π-π interaction, resulting in poor dispersion in the polymer matrix. In this study, silver nanoparticles anchored reduced graphene oxide (Ag/rGO) were first prepared using one-pot synchronous reduction of Ag+ and GO solution via glucose. The thermally conductive (Ag/rGO)/polyimide ((Ag/rGO)/PI) nanocomposites were then obtained via electrospinning the in situ polymerized (Ag/rGO)/polyamide electrospun suspension followed by a hot-press technique. The thermal conductivity (λ), glass transition temperature (Tg), and heat resistance index (THRI) of the (Ag/rGO)/PI nanocomposites all increased with increasing the loading of Ag/rGO fillers. When the mass fraction of Ag/rGO (the weight ratio of rGO to Ag was 4:1) fillers was 15%, the corresponding (Ag/rGO)/PI nanocomposites showed a maximum λ of 2.12 W/(m K). The corresponding Tg and THRI values were also enhanced to 216.1 and 298.6 °C, respectively. Furthermore, thermal conductivities calculated by our established improved thermal conduction model were relatively closer to the experimental results than the results obtained from other classical models.