High-performance Graphene Oxide Research Articles

Simultaneous enhancement in mechanical and physical properties of graphene-oxide-reinforced Al matrix composites by trace-Mg-alloying strategy

This paper proposes a trace-Mg-alloying strategy to fabricate high-performance graphene oxide (GO)-reinforced Al metal matrix composites (MMC). A minute quantity (0.4 wt%) of elemental Mg was introduced in Al–Si alloy powders. Individual GO nanosheets were uniformly decorated onto the surface of the AlSiMg particle through electrostatic attractions via hetero-agglomeration. A GO network was formed at the primary boundaries of AlSiMg particles through spark plasma sintering of GO/AlSiMg mixed powders. In this process, elemental Mg reacted with the oxygen atoms within GO nanosheets, resulting in the in situ production of high-quality reduced GO. Subsequent hot extrusion disrupted the GO network owing to the metal plastic flow, causing the GO nanosheets to realign in a single direction. Consequently, the tribological behavior, tensile response, and thermal and electrical conductivities of the GO/AlSiMg composites were simultaneously enhanced. Hot extrusion led to stretching of the overlapping GO nanosheets and increased surface contact area of AlSiMg powders. Thus, the extruded samples exhibited peak electrical conductivity at 0.2 wt% GO, whereas the sintered samples demonstrated peak thermal conductivity at 0.1 wt% GO. Overall, the findings of this study highlight the potential of merging trace powder alloying and powder metallurgy techniques to create multifunctional nanocarbon/MMCs without a trade-off between mechanical and physical performance.

High-performance asparagine-modified graphene oxide membranes for organic dyes and heavy metal ion separation

Asparagine-modified GO membranes are prepared to efficiently reject rhodamine B dye up to 99.9%, along with a water permeability of ∼1740 ± 10 L m−2 h−1 bar−1. Further, such membranes are stable in water up to 34 days.

LEGO® brick-inspired ultra-stable and rapid transport 2D membrane for fast water purification

Inspired by the modular homogenization and interlocking structure concepts of LEGO® bricks, we developed high-performance graphene oxide composite nanofiltration membranes using the subject–object recognition effect.

Development of High Electrochemical Performance-Reliability TiO2 Nanoparticle-Mulberry Paper Based Supercapacitor

The paper-based energy storage systems with lightweight, thin and large scalability have been attracted much attention in the field of next generation research. Along with the advantages of these papers, they have excellent flexibility and wettability, so they have high power density even under mechanical bending and twisting deformation, making them suitable for wearable devices. However, conventional paper has limited electrochemical stability due to its low chemical resistance and decomposition in organic or acidic electrolytes.Mulberry paper can be an outstanding alternative for overcoming the limitations of conventional paper-based energy storage systems. Mulberry fibers form a stronger mechanical network and are longer than conventional paper fibers, so they have excellent chemical strength. Therefore, in this study, a supercapacitor with high electrochemical performance and reliability was produced based on mulberry paper.As high electrochemical performance active materials, TiO2 nanoparticle and graphene oxide nanocomposites were used. A TiO2 nanoparticle was coated on a mulberry paper substate, graphene oxide was coated, and heat treatment was performed at 700℃ under nitrogen atmosphere for 3 hours. Mulberry paper was carbonized to increase areal energy density. It was strongly fixed by the reduced graphene oxide to maintain the flexibility of carbonized mulberry paper and prevent the delamination of the TiO2 nanotube without protection layer.Therefore, it is suitable for wearable energy storage systems because it can maintain excellent charge-discharge cycle reliability and flexibility carbonized mulberry paper by improving areal energy density from carbonized mulberry paper and metal oxides and preventing the delamination of the metal oxide.

Investigation of supercapacitor electrode performances of phosphorus-doped graphene oxide electrodes in various deep eutectic solvents and symmetric supercapacitor application

A one-step preparation method of phosphorus-doped graphene oxide electrode (P-GOE) was used as electrode material for high-performance supercapacitors. Phosphorus-doped graphene oxides were synthesized on pencil graphite electrodes in one step with easy, cheap, and non-toxic chemicals by using the chronoamperometric process. Electrochemical analyses were carried out to examine the capacitive behavior of the electrodes in different deep eutectic solvents (DESs) (choline chloride:ethylene glycol (ChCl:EG), choline chloride:urea (ChCl:U), choline chloride:phenol (ChCl:Ph)). The electrolytes used make research valuable because these electrolytes were environmentally friendly, non-toxic, and inexpensive. Electrodes were analyzed by cyclic voltammetry at different scan rates, charge-discharge test at different current densities, 1000-cycle galvanostatic charge-discharge test, and electrochemical impedance spectroscopy (EIS). Structural and morphological properties of the electrodes were investigated by FTIR, XRD, SEM, BET, and XPS. As a result of the characterization and electrochemical analysis, it was seen that the phosphorus doping to the electrodes were carried out successfully. The maximum areal capacitances of phosphorus-doped graphene oxide electrodes were calculated to be 450 mF.cm−2, 140 mF.cm−2, and 400 mF.cm−2 in electrolytes for supercapacitor applications. In this study, high-performance P-doped graphene oxide electrodes were produced with an easy method using inexpensive and non-toxic solvents, providing an important contribution as environmentally friendly and sustainable electrode materials for supercapacitor applications.

Universal protocol for the wafer-scale manufacturing of 2D carbon-based transducer layers for versatile biosensor applications

In this manuscript, we present a comprehensive fabrication protocol for high-performance graphene oxide (GO) sensor concepts. It is suitable for a variety of biosensing applications and contains the essential process steps, starting with vapor phase evaporation for siloxane monolayers, followed by spin-coating of GO as a nanometer-thin transducer with exceptional homogeneity and micromechanical surface methods which enable seamless transformation of GO transducers to be desired micro and nano dimensions.In addition to linking basic research and innovative sensor concepts with an outlook for commercial applications of point-of-care systems for early-stage diagnostics, the authors consider it necessary to take a closer look at the manufacturing processes to create more transparency and clarity, to manufacture such specific sensor concepts systematically. The detailed manufacturing approaches are intended to motivate practitioner to explore and improve this GO-based key technology.This process development is illustrated below using the manufacturing methods for three types of sensors, namely sensors based on i) surface plasmon resonance spectroscopy (SPR), ii) impedance spectroscopy and iii) bio-field effect transistors (ISFETs).The obtained results in this work prove successful GO sensor productions by achieving:•Uniform and stable immobilization of GO thin films,•High yield of sensor units on a wafer scale, here up to 96 %,•Promising integration potential for various biomedical sensor concepts to early-stage diagnostic.

Dual-confinement effect in metal oxide nanoparticles/MXene-reduced graphene oxide for high capacitive deionization performance

Metal oxide nanoparticles are one kind of important electrode materials for capacitive deionization (CDI) application. Unfortunately, most metal oxide materials usually exhibit poor electrical conductivity and often experience slow dissolution of metallic species, thereby resulting in limited desalination performance. Overcoming these obstacles still remains challenging due to the lack of synthetic approaches. Taking it into consideration, herein we proposed a dual confinement strategy to promote the CDI application of metal oxide nanoparticles. Nb2O5 was synthesized as a typical example for designing metal oxide/MXene-reduced graphene oxide (rGO) derived from Nb2CTx MXene/graphene oxide (GO) under hydrothermal condition. In the hybrid, Nb2CTx and rGO serve as both the confinement agent and conductive support for Nb2O5 nanoparticles, endowing Nb2O5/Nb2CTx-rGO with improved electronic conductivity and structural stability. As a result, the hybrid shows an outstanding desalination performance, including a NaCl adsorption capacity of 41.07 mg g−1, an ultra-fast average NaCl adsorption rate of 4.14 mg g−1 min−1 and excellent long-term cycling stability of 50 cycles (81 % desalination capacity retention rate). This work is expected to bring new insights in the synthesis of metal oxide materials for electrochemical desalination.

Preparation of graphene oxide composite nitrogen-doped carbon (GO@NCs) by one-step carbonization with enhanced electrosorption performance for U(VI)

High-performance graphene oxide composite nitrogen-doped carbon (GO@NCs) materials were prepared at different temperatures (600, 700 and 800 °C) by a one-step carbonization method. The electrosorption performances of GO@NCs for U(VI) were investigated. The results showed that the specific surface area of GO@NC-700 was 266.3 m2·g−1. The doped nitrogen mainly existed in the form of pyridine (N-6), pyridine (N-5), and quaternary-N (N-Q). The incorporation of nitrogen atoms and graphene oxide effectively improved the electrochemical performance of the material, and the maximum specific capacitance of GO@NC-700 was 289.8 F·g−1. At the same time, nitrogen-containing functional groups improved the selectivity to uranium and weakened the repulsive effect of coexisting ions. Therefore, the removal efficiency of GO@NC-700 electrode structure can reach 98.63 % at −1.2 V (vs. SCE, pH = 5). The maximum adsorption capacity of GO@NC-700 was 879.2 mg·g−1, which was 4 times higher than that of simple adsorption (202.3 mg·g−1). The material had good cycle performance, and the capacity loss was less than 10 % after 5 cycles. The above results show that the GO@NC-700 electrode had special potential applications in removing uranium from aqueous solutions, which provides a new and effective method for the treatment of uranium-containing wastewater. Environmental implicationGraphene oxide composite nitrogen-doped carbon (GO@NCs) can effectively separate uranium (VI) from the solution and reduce its threat to the environment and human body.

High-performance porous graphene oxide hollow fiber membranes with tailored pore sizes for water purification

Though graphene oxide (GO) membranes hold a good promise for water purification, their performance is restricted by permeation through long and tortuous diffusional pathways, leading to lower water permeance. In this study, we proposed a mild chemical etching approach to create nano-scale pores on the basal plane of GO nanosheets to make hollow fiber (HF) porous GO (PGO) membranes with improved water permeance and good dye rejection performance. Various characterization techniques were performed to monitor the pore generation and structural and compositional changes of synthesized PGO nanosheets. Results revealed that by controlling the etching time, PGO nanosheets with tunable pore size and surface chemistry as well as good solution processability were synthesized. The fabricated PGO HF membranes showed a well-stacked laminar morphology with uniform structures. The membrane made of PGO nanosheets etched for 5h (named PGO_5h) exhibited a 23-fold enhancement in pure water permeance from 0.129 LMHBar −1 for pristine GO membrane to 2.98 LMHBar −1 . Rejection tests with dyes in the molecular weights range between 200 and 900 g mol −1 were performed to prob the sieving capacity of the membranes on dye-containing wastewaters. The PGO_5h membrane showed molecular weight cut-off (MWCO) about 500 g mol −1 , demonstrating the great potential of PGO HF membranes for nanofiltration applications. • Porous graphene oxide (PGO) synthesis using mild chemical etching technique. • Controlling the pore sizes on the PGO by altering treatment times. • Processing the synthesized PGO into membranes on alumina hollow fibre support. • 23-folds enhancement in water permeation compared to pristine GO membranes. • Reject molecular of size larger than around 500 g mol −1 .

Water‐Light Induced Self‐Blacking System Constituted by Quinoa Cellulose and Graphene Oxide for High Performance of Salt‐Rejecting Solar Desalination

AbstractSalt deposits are a key challenge of solar driven desalination technology due to the fact that the evaporation rate of the system sharply deteriorates when salt accumulates. In this paper, a self‐blacking aerogel (SBA) is first demonstrated with excellent deposited salt self‐cleaning performance, and the self‐cleaning mechanism is illustrated by the theory of chemical potential. The color of the SBA can be changed from light brown to black under the inducement of water and light, and its light absorption ability clearly increases from 34.5% to 77.0% in the whole spectral range (200–2500 nm). SBA is fabricated by quinoa bran cellulose (QBC) and graphene oxide (GO) with an evaporation rate of 3.6 kg m−2 h−1 under one sun. Importantly, for natural solar irradiation, the average evaporation rate reaches up to 12.6 and 12 kg m−2 day−1 in the period of 15 days of outdoor experiments for pure water and stimulated seawater respectively, which can meet the drinking water demand for 5–6 people. This work provides a convenient strategy to improve the salt deposit problem with high evaporation rate, and low cost for practical desalination, with water purification applications.

Interfacial assembled mesoporous polydopamine nanoparticles reduced graphene oxide for high performance of waterborne epoxy-based anticorrosive coatings

Embedding two-dimension micro/nanocontainers containing corrosion inhibitors into organic coating is a well-established concept to impart the coating with enhanced barrier and self-healing feature. Herein, a versatile nanoemulsion assembly approach was used to synthesis nanocarriers combing mesoporous polydopamine nanoparticles (MPDA) with reduced graphene oxide (GO), which was employed to encapsulate corrosion inhibitors (benzotriazole, BTA) to improve the anticorrosion performance of waterborne epoxy coating. The BTA release profiles from synthesized GO with MPDA (PDAG) demonstrated the rapid pH-triggered activities to acidic corrosion environment. With the addition of BTA-loaded PDAG, the composited epoxy coatings presented self-repairing behavior and enhanced corrosion resistance during long-term immersion. The outstanding anticorrosion performance is attributed to dual-protection mechanism provided by BTA-loaded PDAG: (1) MPDA endows GO with satisfactory interface compatibilities and thus provides impermeable barrier to delay the penetration process of corrosive electrolyte; (2) corrosion inhibitors including BTA and polydopamine form the adsorption layers on bare steel surface to resist continuous corrosion at metal/coating interface.

Bioinspired Graphene Oxide Membranes with pH-Responsive Nanochannels for High-Performance Nanofiltration.

Tunable gating graphene oxide (GO) membranes with high water permeance and precise molecular separation remain highly desired in smart nanofiltration devices. Herein, bioinspired by the filtration function of the renal glomerulus, we report a smart and high-performance graphene oxide membrane constructed via introducing positively charged polyethylenimine-grafted GO (GO-PEI) to negatively charged GO nanosheets. It was found that the additional GO-PEI component changed the surface charge, improved the hydrophilicity, and enlarged the nanochannels. The glomerulus-inspired graphene oxide membrane (G-GOM) shows a water permeance up to 88.57 L m-2 h-1 bar-1, corresponding to a 4 times enhancement compared with that of a conventional GO membrane due to the enlarged confined nanochannels. Meanwhile, owing to the electrostatic interaction, it can selectively remove positively charged methylene blue at pH 12 and negatively charged methyl orange at pH 2, with a removal rate of over 96%. The high and cyclic water permeance and highly selective organic removal performance can be attributed to the synergic effect of controlled nanochannel size and tunable electrostatic interaction in responding to the environmental pH. This strategy provides insight into designing pH-responsive gating membranes with tunable selectivity, representing a great advancement in smart nanofiltration with a wide range of applications.

High-Performance Porous Graphene Oxide Hollow Fiber Membranes with Tailored Pore Sizes for Water Purification

High-Performance Porous Graphene Oxide Hollow Fiber Membranes with Tailored Pore Sizes for Water Purification

Sewage concentration via a graphene oxide modified thin-film nanocomposite forward osmosis membrane: Enhanced performance and mitigated fouling

• The GO modified TFN-FO membrane shows improved filtration performance. • The GO modified TFN-FO membrane shows an enhanced antifouling property. • The GO modified FO membrane has high and stable sewage concentration performance. • High water flux recovery rates can be achieved by simple membrane cleaning. Upstream intensification of wastewater pre-treatment could improve the efficiency of the biological wastewater treatment process by separating and concentrating the organic matter. Forward osmosis (FO) technology is a potential upstream intensification strategy for sewage concentration. Herein, a high-performance graphene oxide (GO) modified TFN-FO membrane was fabricated and evaluated. The GO modified TFN-FO membrane showed 41% enhancement in water flux without weakening the selectivity property, due to the improved membrane hydrophilicity, thinner polyamide layer and facilitated water transportation by GO. The enhanced filtration performance and antifouling property of the TFN-FO membrane were confirmed by using simulative foulant solution and raw sewage as feed solutions. Moreover, a 41 h semi-continuous filtration experiment was conducted for sewage concentration using real raw sewage as the feed solution. Results indicated that the TFN-FO membrane achieved 4.6 times sewage concentration with high rejection of ammonia, nitrogen and organics. In addition, with a simple in-line water cleaning-in-place (CIP) process, most of the pollutants could be washed off from the surface of the TFN-FO membrane in 15 min and ~ 90% water flux could be recovered after each cleaning cycle. This work demonstrates the potential application of TFN-FO membranes for sewage wastewater concentration.

Alternately Dipping Method to Prepare Graphene Fiber Electrodes for Ultra-high-Capacitance Fiber Supercapacitors.

SummaryFlexible fiber supercapacitors are promising candidate for power supply of wearable electronics. Fabrication of high-performance fibers is in progress yet challenging. The currently available graphene fibers made from wet-spinning or electro-deposition technologies are far away from practical applications due to their unsatisfactory capacitance. Here we report a facile alternately dipping (AD) method to coat graphene on wire-like substrates. The excellent mechanical properties of the substrate with greatly diverse choices can be carried over to the fiber supercapacitors. Under such guideline, the graphene fiber with a titanium core made by our AD method (AD:Ti@RGO) shows an ultra-high specific capacitance of up to 1,722.1 mF cm−2, which is ∼1,000 times that of wet-spinning- and electro-deposition-fabricated neat graphene fibers and presents the highest specific capacitance to date. With excellent mechanical properties and striking electrochemical performances, the AD:Ti@RGO-based supercapacitors light the path to the next-generation technologies for wearable devices.

All-inkjet-printed high-performance flexible MoS2 and MoS2-reduced graphene oxide field-effect transistors

Two-dimensional (2D) materials have been utilized to design flexible field-effect transistors (FETs) with promising performance. However, flexible FETs still face challenges with poor switching features and ultra-low drive current. In this paper, a facile and repeatable large-area integration process is presented for inkjet-printed FETs with 2D materials active channels and PI films as gate dielectrics. The MoS2 FETs reported here exhibit n-type channel feature with an outstanding average subthreshold swing of 75 mV/dec, an on-state/off-state current ratio of 104, and on-state current up to 10 μA at a power supply voltage of 3.0 V. Besides, MoS2–rGO FETs also exhibit n-type semiconductor features with good electrical properties by the inkjet-printing technology.

Facile and low-cost synthesis of cobalt-doped MnO2 decorated with graphene oxide for high performance 2.3 V aqueous asymmetric supercapacitors

Efficient and novel cobalt doped MnO2 nanowires decorated with Graphene oxide was successfully synthesized with hydrothermal method and ultrasonic process. The nanocomposite phase was confirmed by XRD and XPS data. TEM and HRTEM analysis showed the good dispersion of MnO2 nanowires on graphene oxide sheets. Benefiting from the synergistic effect between cobalt-doped MnO2 nanowires and graphene oxide, the electrode material showed a satisfactory electrochemical performance with high specific capacitance of 397 F g−1 at 0.5 A g−1, high rate capability (328 F g−1 at 20 A g−1), and excellent capacitance retention only 2.5% decay after 4000 cycles at 10 A g−1 current density. As application for asymmetric supercapacitor device, the Cobalt doped MnO2 decorated with graphene oxide (MCo(0.25)/GO) electrode achieved a wide potential window up to 2.3 V with a high energy density of 35.3 Wh·kg−1 at power density of 590 W kg−1. Moreover, an energy density value of 25.8 Wh·kg−1 is maintained at high power density (5.6 kW kg−1). Therefore, the prepared MCo(0.25)/GO nanocomposite, with outstanding electrochemical performance, is considered as suitable and great potential application for supercapacitor device in the next generation.

Facile synthesis of high-performance LiFePO4-reduced graphene oxide composites using ball milling

We developed a simple, green, and solvent-free method for the synthesis of LiFePO4-reduced graphene oxide (LFP-RGO) composites with enhanced electrochemical performance. RGO sheets (synthesized using supercritical ethanol) and LFP precursors (produced using a co-precipitation method) were uniformly mixed by ball milling. The micron-sized co-precipitated LFP precursors were partially pulverized, and the RGO sheets were uniformly distributed in the LFP precursors during the ball milling process. After subsequent calcination of the LFP precursor-RGO mixture, a uniform coverage of RGO sheets with thickness of approximately 10 nm was observed on the surface of the LFP particles. The LFP-RGO composite exhibited a high reversible capacity of 158 mAh g−1 at 0.1 C, an excellent rate performance of 92 mAh g−1 at 10 C, and an extremely small decay rate of 0.021 mAh g−1 per cycle over 1000 cycles at 1 C. The effects of the RGO content and ball milling speed on the physicochemical and electrochemical properties of the LFP-RGO composites were discussed.

Natural Biodegradable Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) Nanocomposites with Multifunctional Cellulose Nanocrystals/Graphene Oxide Hybrids for High-Performance Food Packaging.

High-performance and useful graphene oxide (GO) and cellulose nanocrystals (CNCs) are easily extracted from natural graphite and cellulose raw materials, and poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) is produced by bacterial fermentation from natural plant corn stalks, etc. In this study, novel ternary nanocomposites consisting of PHBV/cellulose nanocrystal-graphene oxide nanohybrids were prepared via a simple solution casting method. The synergistic effect of CNC with GO nanohybrids obtained by chemical grafting (CNC-GO, covalent bonds) and physical blending (CNC/GO, noncovalent bonds) on the physicochemical properties of PHBV nanocomposites was evaluated and the results compared with a single component nanofiller (CNC or GO) in binary nanocomposites. More interestingly, ternary nanocomposites displayed the highest thermal stability and mechanical properties. Compared to neat PHBV, the tensile strength and elongation to break increased by 170.2 and 52.1%, respectively, and maximum degradation temperature (Tmax) increment by 26.3 °C, were observed for the ternary nanocomposite with 1 wt % covalent bonded CNC-GO. Compared to neat PHBV, binary, and 1:0.5 wt % noncovalent CNC/GO based nanocomposites, the ternary nanocomposites with 1 wt % covalent bonded CNC-GO exhibited excellent barrier properties, good antibacterial activity (antibacterial ratio of 100.0%), reduced barrier properties, and lower migration level for both food simulants. Such a synergistic effect yielded high-performance ternary nanocomposites with great potential for bioactive food packaging materials.

High-Performance Graphene Oxide Nanofiltration Membranes for Black Liquor Concentration

Black liquor (BL) concentration by multieffect evaporation is an extremely energy-intensive operation in the kraft pulping cycle. Membranes can significantly save energy in this process, but conven...