Mesoporous Graphene Research Articles

Honeycomb-like SBA-15 parceled in 2D GO for ultrafiltration membranes fabrication with ultrahigh permeability and enhanced anti-fouling performance

Novel 3D mesoporous silica SBA-15 and 2D graphene oxide (GO) composite nano-fillers incorporated polysulfone (PSf) ultrafiltration (UF) membranes (GO-SBA-15/PSf) were first prepared via blending modifications by non-solvent induced phase separation (NIPs). 3D honeycomb-like SBA-15 not only improved the surface hydrophilicity but also provided extra nano-channels parceled in 2D GO networks for convenient hydrone transport via confinement-effect. The lamellar GO networks relieved the agglomeration of inorganic materials inside the polymer, anticipating in the interfacial polymerization reaction. GO-SBA-15/PSf UF membranes were systematically investigated using contact angle, scanning electron microscopy (SEM), transmission electron microscopy (TEM), atomic force microscope (AFM) and Brunauer-Emmett-Teller (BET) methods. The pure water flux reached 641.7 L m-2h−1 which was 3 times than that of pristine PSf membranes (229.2 L m-2h−1) under the pressure of 0.1 MPa. Negative charge of GO generated electrostatic repulsion with protein, which facilitated a high rejection of 98.22% and excellent FRR value of 85% that was 1.5 times than that of pristine PSf membranes (58%). The UF membranes fabricated by new multidimensional nano-fillers overcame the trade-off effect between permeability and protein rejection.

Feather-like Gold Nanostructures Anchored onto 3D Mesoporous Laser-Scribed Graphene: A Highly Sensitive Platform for Enzymeless Glucose Electrochemical Detection in Neutral Media.

The authors present a novel sensing platform for a disposable electrochemical, non-enzymatic glucose sensor strip at physiological pH. The sensing material is based on dendritic gold nanostructures (AuNs) resembling feather branches, which are electrodeposited onto a laser-scribed 3D graphene electrode (LSGE). The LSGEs were fabricated via a one-step laser scribing process on a commercially available polyimide sheet. This study investigates several parameters that influence the morphology of the deposited Au nanostructures and the catalytic activity toward glucose electro-oxidation. The electrocatalytic activity of the AuNs-LSGE was evaluated using cyclic voltammetry (CV), linear sweep voltammetry (LSV), and amperometry and was compared to commercially available carbon electrodes prepared under the same electrodeposition conditions. The sensor demonstrated good stability and high selectivity of the amperometric response in the presence of interfering agents, such as ascorbic acid, when a Nafion membrane was applied over the electrode surface. The proposed sensing strategy offers a wide linear detection range, from 0.5 to 20 mM, which covers normal and elevated levels of glucose in the blood, with a detection limit of 0.21 mM. The AuNs-LSGE platform exhibits great potential for use as a disposable glucose sensor strip for point-of-care applications, including self-monitoring and food management. Its non-enzymatic features reduce dependence on enzymes, making it suitable for practical and cost-effective biosensing solutions.

Well-dispersed cobalt magnetic nanoparticles incorporated into 3D mesoporous graphene

Well-dispersed cobalt magnetic nanoparticles incorporated into 3D mesoporous graphene

Synthesis of Graphene Oxide-Coated Mesoporous Silica with Cetyltrimethylammonium Bromide (CTAB) Template for Methylene Blue Adsorption

The synthesis of graphene oxide-coated mesoporous silica (MS_GO) with the template surfactant (Cetyltrimethylammonium Bromide) CTAB has been carried out. The effect of combining mesoporous silica and graphene oxide was studied by knowing the bonds, functional groups and crystalline structures. Functional groups C=O and C=C were formed at wave numbers 1,722, 1,617 and 1,647 cm−1, respectively, as a characteristic of GO compounds. XRD data showed that MS_GO has a more amorphous structure than graphite and GO due to the incorporation of silica onto the graphene oxide surface. The MS_GO synthesis was also applied as an adsorbent for methylene blue dye in water. The adsorption results showed that MS_GO was more effective than pure GO. The percent adorption efficiency (R %) of MS_GO against 10 ppm methylene blue was 93.1 % while that of pure GO was 91.5 %. The addition of mesoporous silica to graphene oxide makes MS_GO adsorbent more effective in adsorption dyes than pure GO, this is supported by the larger total surface area of BET MS_GO was 161.066 m2·g−1, while that of pure GO was 103.818 m2·g−1. HIGHLIGHTS Preparation of graphene oxide from graphite by the modified hummer method Mesoporous silica is synthesized with Graphene Oxide (GO) and occupies between GO layers in the GO interlayer space CTAB is used as a template and forms pores in the synthesis of layered Mesoporous Silica-Graphene Oxide (MS_GO) Graphene Oxide-Coated Mesoporous Silica will be applied for adsorption of methylene blue dye in water. The adsorption efficiency (% R) of GO against methylene blue is lower than % R of MS_GO against methylene blue GRAPHICAL ABSTRACT

Efficient decontamination of aqueous glyphosate using Santa Barbara Amorphous-15 (SBA-15) and graphene oxide-SBA-15 poly-amidoamine functionalized composites

There are serious concerns about the effects of aqueous glyphosate on humans especially after its re-classification as a probable carcinogen. Thus, poly-amidoamine functionalized mesoporous SBA-15 (PSBA) and graphene oxide-SBA-15 (PGOSBA) composites were synthesized and employed for aqueous glyphosate decontamination via adsorption. Glyphosate adsorption on the PSBA and PGOSBA was ≥ 265% enhanced than on SBA-NH2. There were fast equilibrium attainments for the composites at 30 and 60 min, respectively, and no significant differences in adsorption trend were observed as solution pH and temperature varied. The fractal pseudo-second-order kinetics model and fractal Brouers–Sotolongo adsorption isotherm model fitted the adsorption data better indicating complex glyphosate adsorption mechanisms involving electrostatic interactions, pore-filling processes, and multi-layer adsorption. The composites are reusable and stable after several cycles retaining ≥ 77% of their original adsorption potential after 3 consecutive cycles. The PGOSBA and PSBA composites could reduce low-concentration glyphosate solutions to 182.9 ± 105.7 and 235.9 ± 4.2 µg/L, respectively, which are below the maximum permissible limits for several countries (Canada/Argentina–280 µg/L; the United States/China–700 µg/L; and Australia–1000 µg/L). These adsorbents are efficient and could be applied over wide aqueous pH, temperature, and concentration ranges, and thus would be potentially viable economically for water treatment.

A mesoporous graphene @ zirconium-based metal–organic frameworks as a matrix and an adsorbent for steroid detection using surface-assisted laser desorption/ionization time-of-flight mass spectrometry

Endocrine-disrupting chemicals (EDCs) in environmental water samples, a rapid, sensitive, and high-throughput method should be developed. In this study, an in situ-synthesized composite material of three-dimensional mesoporous graphene (3D-MG) and zirconium-based metal–organic frameworks (MOFs), denoted as MG@UiO-66, was used as both the adsorbent and matrix in surface-assisted laser desorption/ionization time-of-flight mass spectrometry (SALDI-TOF MS) for steroid detection. Both graphene-based materials and MOFs have proven to be ineffective in detecting steroids as a matrix; however, their composites can detect steroids with higher sensitivity and lower interference. After screening different types of MOFs, a composite of UiO-66 and 3D-MG was selected as the new matrix for steroid detection. The combination of 3D-MG and UiO-66 further enhanced the ability of the material to enrich steroids, and reduced the limit of detection (LOD) of steroids. The method was evaluated for linearity, LODs, limit of quantitation (LOQs), reproducibility, and precision under optimized conditions. The results showed that the linear relationships of three steroids are kept in the range of 0–300 nM/L with a correlation coefficient r ≥ 0.97. The LODs and LOQs of the steroids were in the range of 3–15 and 10–20 nM/L, respectively. Recoveries (n = 5) of 79.3–97.2% were obtained at three spiked levels in the blank water samples. This fast and efficient method of using SALDI-TOF MS can be extended to detect the steroids in EDCs in environmental water samples.

Coordinating Interface Polymerization with Micelle Mediated Assembly Towards Two-Dimensional Mesoporous Carbon/CoNi for Advanced Lithium-Sulfur Battery.

Lithium-sulfur battery has attracted significant attention by virtues of their high theoretical energy density, natural abundance, and environmental friendliness. However, the notorious shuttle effect of polysulfides intermediates severely hinders its practical application. Herein, a novel 2D mesoporous N-doped carbon nanosheet with confined bimetallic CoNi nanoparticles sandwiched graphene (mNC-CoNi@rGO) is successfully fabricated through a coordinating interface polymerization and micelle mediated co-assembly strategy. mNC-CoNi@rGO serves as a robust host material that endows lithium-sulfur batteries with a high reversible capacity of 1115 mAh g-1 at 0.2 C after 100 cycles, superior rate capability, and excellent cycling stability with 679.2 mAh g-1 capacity retention over 700 cycles at 1 C. With sulfur contents of up to 5.0mg cm-2 , the area capacity remains to be 5.1 mAh cm-2 after 100 cycles at 0.2 C. The remarkable performance is further resolved via a series of experimental characterizations combined with density functional theory calculations. These results reveal that the ordered mesoporous N-doped carbon-encapsulated graphene framework acts as the ion/electron transport highway with excellent electrical conductivity, while bimetallic CoNi nanoparticles enhance the polysulfides adsorption and catalytic conversion that simultaneously accelerate the multiphase sulfur/polysulfides/sulfides conversion and inhibit the polysulfides shuttle.

Sb (III) Removal from Aqueous Solutions by the Mesoporous Fe3O4/GO Nanocomposites: Modeling and Optimization Using Artificial Intelligence

The mesoporous graphene oxide-supported ferroferric oxide (Fe 3 O 4 /GO) nanocomposites (the average size of 30.08 nm) were controllably synthesized in the present study. The successful in situ growth of Fe 3 O 4 nanoparticles on GO surface was ascribed to the oxygen-containing groups on GO. The magnetic separation was employed for Sb(III) removal from aqueous solutions and artificial intelligence techniques were adopted to reduce the number and cost of experiments, in order to render these nanocomposites of a practical value. The three methods, including response surface methodology (RSM), artificial neural network-genetic algorithm (ANN-GA) and artificial neural network-particle swarm optimization (ANN-PSO), were used to model and optimize the removal of Sb(III) from aqueous solutions. These three models were evaluated based on correlation coefficient (R 2 ) and mean squared error (MSE). The higher R 2 value and lower MSE of ANN-GA demonstrated the superiority of ANN-GA model over ANN-PSO and RSM models. Analysis of variance, gradient boosted regression trees (GBRT) and Garson method exhibited that contact time was the most influential variable for the Sb(III) removal. Fitting of isotherm data showed that the removal process was controlled by the monolayer adsorption on a homogeneous surface based on the values of R 2 , x 2 , sum of absolute errors (SAE) and average percentage errors (APE). The adsorption process followed the pseudo-second-order model, which was spontaneous and entropy-driven. It was observed that the adsorption process was accompanied with the redox reaction based on the XPS analysis. The regeneration experiments showed that the mesoporous Fe 3 O 4 /GO nanocomposites are an effective and reusable adsorbent within four regeneration cycles.

A Smart Anticorrosive Epoxy Coating Based on Graphene Oxide/Functional Mesoporous Silica Nanoparticles for Controlled Release of Corrosion Inhibitors

When mesoporous nanomaterials and graphene oxide have been used in anti-corrosion coatings, new nanocoatings have attracted greater attention. Adding nano-fillers with special structures and corrosion inhibitors to epoxy coatings has been proven to effectively enhance the corrosion resistance of coatings. However, studies have pointed out that the added corrosion inhibitors are easily degraded by UV light and react with the metal substrate or materials in the coating, resulting in a significant reduction in the service life of the coating. To this end, in this study, the corrosion inhibitor was encapsulated in mesoporous silica with pH response, and the functional silica was composited with graphene oxide to prepare novel graphene oxide/functional mesoporous silica nanoparticles. Coatings with this special filler added have strong anti-corrosion potential and can be applied in marine anti-corrosion contexts, such as containers, in the future. The filler not only has a physical barrier ability but also can effectively prevent the degradation of the inhibitor due to ultraviolet rays. At the same time, in the early stage of corrosion, the release of inhibitors can be effectively controlled by the change in PH to achieve the purpose of preventing corrosion. UV spectrophotometry confirmed the stable encapsulation and controlled release of the inhibitor. Electrochemical-impedance spectroscopy showed that the |Z|0.01 Hz value of the smart anti-corrosion epoxy coating was about 10,000 times higher than that of the pure epoxy coating. Through the FT-IR mapping test, it was found that in the area of mechanical damage, the alkaline environment created by the initial corrosion can induce the release of tannic acid and react with common corrosion products to form iron tannins, which effectively inhibits the further occurrence of corrosion. This method provides an effective method for the design of heavy-duty anti-corrosion coatings.

Rapid adsorption of sulfamethazine on mesoporous graphene produced from plastic waste: optimization, mechanism, isotherms, kinetics, and thermodynamics

Sulfonamide antibiotics like sulfamethazine (SMZ) can threaten aquatic and terrestrial life even in small concentrations (≤ 1 mg/L); hence, their removal from wastewater is indispensable. However, the need to explore new promising adsorbents that are cheap, effective, and reusable also remains crucial to developing adsorption technology. This work presents a one-pot solvent-free conversion of the current most ubiquitous anthropogenic bio-resistant solid waste (plastics) into valuable carbon materials to remove SMZ from aqueous solution. High-density polyethylene waste was pyrolyzed at 500–1000 °C in an enclosed stainless-steel reactor to produce mesoporous graphene. The graphene products were characterized via microscopic and spectroscopic analyses. The effect of temperature on the graphene yield and properties was investigated. The optimum sulfamethazine (SMZ) adsorption was achieved with 600 °C carbon product (CP-600) due to its high porosity and aromatic structure. The adsorption parameters (pH, catalyst dose, and SMZ concentration) were optimized by response surface methodology (RSM) with a central composite design. 99.99% SMZ removal was achieved at 0.9 g/L adsorbent dose, 12.4 mg/L SMZ concentration, and pH 3 at 25 °C. FTIR analysis revealed that the SMZ adsorption occurred mainly via π–π/π+–π electron interactions between the aromatic and pyrimidine rings of SMZ and the benzene ring of graphitic CP-600. The SMZ adsorption followed the pseudo-second-order kinetics, Langmuir, and Freundlich isotherm models. The adsorption was controlled by film and intraparticle diffusion and was spontaneous and endothermic. The carbon synthesized in this work is reusable and can rapidly remove more SMZ than other SMZ adsorbents.

Mesoporous graphene-based hybrid nanostructures for capacitive energy storage and photocatalytic applications

The development of multi-functional nanomaterials is nowadays more than a necessity to address both energy and environmental needs of our society. In this perspective, the hybridization of graphene (Gr) with TiO2 nanotubes (TiNT) is very promising to meet these issues. In the present work, bi-functional graphene-modified TiO2 nanotubes electrodes (Gr/TiNT) were successfully prepared. A simple and effective approach for graphene production, by electrochemical exfoliation of pure graphite foil in inorganic salt (Na2SO4) is used. Graphene sheets were formed on the surface of TiO2 nanotube arrays through electrodeposition process by chronoamperometry. Mesoporous graphene of high surface area is promising material for photocatalytic applications. Gr/TiNT electrode displays significantly improved photodegradation efficiency to MB, achieving a degradation percentage of 60% in 2 hours, which is about 50% higher than that of TiNT. Moreover, Gr/TiNT with high conductivity demonstrated good capability to deliver extremely high energy and power in a very short period of time, the relaxation time constant was only about 48 ms, which is far lower than that of most conventional activated carbon-based electrochemical capacitors. Capacitance retention of 98% was also demonstrated after 1000 cycles.

Mechanical and antibacterial properties of resin co-filled with mesoporous silica and graphene quantum dots

Mechanical and antibacterial properties of resin co-filled with mesoporous silica and graphene quantum dots

Efficient Electrochemical Oxygen Reduction to Hydrogen Peroxide Production from Nickel-Nitrogen-Doped Mesoporous Graphene Catalyst

Hydrogen peroxide(H2O2) is an excellent oxidizing agent with various uses in industrial bleaching, chemical synthesis, and wastewater treatment. Because of its wide range of applications, the global market demand is rapidly increasing. At present, over 95 % of H2O2 is produced through the anthraquinone process which is an environmentally unfriendly process. Therefore, numerous studies have focused on replacing this process for H2O2 with more eco-friendly processes. One of the alternative methods is the electrochemical production of H2O2 through oxygen reduction reaction(ORR), which offers an economical and environmentally friendly route to H2O2.The oxygen reduction reaction involves a multielectron transfer process in which O2 can be reduced to produce H2O in a four-electron process or undergo a two-electron pathway to form H2O2. However, the design of selective and active electrocatalysts remains a challenge due to competitive reaction pathways between two-electron and four-electron reduction.We develop 3D mesoporous graphene with high H2O2 production in neutral electrolytes by adjusting the pore size and regulating the atmosphere of Nickel single atom. This catalyst has 3D interconnected hollow N-doped graphene shells and Nickel single atoms will be atomically dispersed on N-doped graphene shells. The mesoporous structure with a large surface area accelerates mass transport. Moreover, electron-poor Nickel atoms yield high selectivity above 90 % and high activity for electrochemical oxygen reduction to produce H2O2 in neutral conditions. This result represents a benchmark for the two-electron ORR electrocatalyst in the neutral conditions.

Soft Template-Assisted Fabrication of Mesoporous Graphenes for High-Performance Energy Storage Systems.

Graphene is a promising active material for electric double layer supercapacitors (EDLCs) due to its high electric conductivity and lightweight nature. However, for practical uses as a power source of electronic devices, a porous structure is advantageous to maximize specific energy density. Here, we propose a facile fabrication approach of mesoporous graphene (m-G), in which self-assembled mesoporous structures of poly(styrene)-block-poly(2-vinylpyridine) copolymer (PS-b-P2VP) are exploited as both mesostructured catalytic template and a carbon source. Notably, the mesostructured catalytic template is sufficient to act as a rigid support without structural collapse, while PS-b-P2VP converts to graphene, generating m-G with a pore diameter of ca. 3.5 nm and high specific surface area of 186 m2/g. When the EDLCs were prepared using the obtained m-G and ionic liquids, excellent electrochemical behaviors were achieved even at high operation voltages (0 ∼ 3.5 V), including a large specific capacitance (130.2 F/g at 0.2 A/g), high-energy density of 55.4 W h/kg at power density of 350 W/kg, and excellent cycle stability (>10,000 cycles). This study demonstrates that m-G is a promising material for high-performance energy storage devices.

Dye removal using novel adsorbents synthesized from plastic waste and eggshell: mechanism, isotherms, kinetics, thermodynamics, regeneration, and water matrices

Abstract High-density polyethylene (HDPE) waste and chicken eggshell were used to synthesize three novel adsorbents, namely mesoporous graphene (MG), nano-eggshell modified graphene (nEMG), and nano-magnetic eggshell modified graphene (nM-EMG) for methyl red (MR) adsorption from simulated wastewater. The effects of adsorption conditions (pH, contact time, initial dye concentration, adsorbent dose, and temperature) were investigated. MG, nEMG, and nM-EMG were characterized using SEM, TEM, BET, EDX, XRD, and FTIR analyses. MG, nEMG, and nM-EMG had specific surface areas of 15, 31, and 179 m2/g and mean pore diameters of 27, 29, and 5 nm respectively. The equilibrium adsorption capacities of MG, nEMG, and nM-EMG were 5.6, 8.1, and 6.5 mg/g respectively at MR concentration of 100 mg/L, pH 4, adsorbent dose of 1.0 g/100 mL, and temperature of 25 °C. All MR sorption processes followed the pseudo-second-order and Langmuir–Freundlich model. The adsorption rates were controlled by intra-particle and film diffusion. MR uptake on the synthesized adsorbents was spontaneous, endothermic, and chemisorption. The adsorption occurred via electrostatic interactions, π electron interactions, and hydrogen bonding. The performance of the prepared adsorbents was examined in different water matrices and compared with other MR adsorbents. After five regeneration cycles, the adsorbent reusability study showed that nM-EMG is the most stable and reusable adsorbent.

Hollow CoO Nanoparticles Embedded in N‐doped Mesoporous Graphene for Efficient Oxygen Reduction Reaction

AbstractDevelopment of reactive and stable non‐preciously metallic catalysts toward oxygen reduction reaction is a fascinating research field for fuel cells. Herein, a hybrid electrocatalyst consisted of hollow CoO nanoparticles embedded in N‐doped mesoporous graphene (CoO@N−G) has been successfully prepared via carbonizing the precursor which is prepared from graphene oxide and N, N′‐Bis(salicylidene) ethylenediamine cobalt salt in the presence of hydrazine hydrate. The formation of hollow CoO nanoparticles is generally attributed to the nanoscale Kirkendall effect. The effective synergistic effect of hollow CoO nanoparticles and N‐doped mesoporous graphene is helpful to obtain excellent electrocatalytic activity with four‐electron selectivity, long‐term stability and good anti‐methanol.

An efficient electrochemical sensor for nitrite based on a mesoporous nickel cobaltite-reduced graphene oxide (NiCo-RGO) nanocomposite

ABSTRACT A simple protocol for the preparation of nickel–cobaltite and graphene–nickel–cobaltite composites is described in this paper. Nickel–cobaltite-reduced graphene oxide (NiCo-RGO) nanoparticles are produced by self-combustion of urea–nitrate complexant. Graphene, as expected, inhibits the nanoparticles from clumping together. The production of complex during synthesis is confirmed by electrochemical and spectroscopic analyses of the composites. Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) were used to investigate the electrocatalytic oxidation of nitrite on a (NiCo-RGO) graphite electrode. The DPV approach demonstrated a linear range of 60–860 μM, with detection limits of 18.0 μM. For nitrite determination, the method’s sensitivity was around 0.06767 μA μM−1 cm−2. Interference, stability, and repeatability were also checked on the sensor. DPV techniques were utilised to examine nitrite levels in soil and juice samples.

Silicone oil nanofluids dispersed with mesoporous crumpled graphene for medium-temperature direct absorption solar-thermal energy harvesting

Direct absorption and conversion of sunlight by optical nanofluids into storable heat is an efficient and facile way to harness abundant clean solar energy, but achieving long-term stable dispersion of the nanofluids is challenging under elevated temperatures. Herein, we report the preparation of mesoporous crumpled graphene particles as self-dispersible solar absorbers that can achieve homogenous dispersion within medium-temperature silicone oil. The mesoporous crumpled graphene particles were synthesized by using an aerosol-assisted capillary compression process and a subsequent oxidative-etching reaction. By controlling the etching time, the introduced mesopores can tune the apparent density of the crumpled particles into a value comparable with the dispersing base fluid. The crumpled surface structure, small particle size and compatible density weaken the inter-particle van der Waals attraction and gravitational sedimentation tendency. The resultant silicone oil nanofluids have maintained their uniform dispersion under a heating temperature of 200 °C for 50 h. The stable uniform dispersion together with the high solar absorptance, the large specific heat capacity and the proper viscosity enabled the application of prepared nanofluids for consistent high-performance medium-temperature solar-thermal energy harvesting under concentrated solar irradiation. • Mesopores are introduced to crumpled graphene particles to tailor the density. • Stable dispersion of mesoporous crumpled graphene particles in silicone oil is achieved. • The nanofluids have high solar absorptance, large heat capacity and suitable viscosity. • Medium-temperature nanofluidic solar-thermal energy harvesting is demonstrated.

Improving catalytic degradation of organic pollutants through highly efficient non-radical peroxymonosulfate activation using interlayer-expanded mesoporous nitrogen-doped graphene

Nitrogen-doped graphene (N-rGO) has shown great potential for activation of peroxymonosulfate (PMS), yet the catalytic reaction rate was rather limited due to concealment of active sites caused by agglomeration of graphene sheets. In this study, SiO2 nanoparticles were introduced to modulate the structure of N-rGO to form an interlayer-expanded mesoporous SiO2@N-rGO. Compared to N-rGO with a 2D structure, the nitrogen contents of SiO2@N-rGO were at the same level, yet the graphene sheets were cracked and the interlayers were expanded due to the intercalation of SiO2 nanoparticles, and a wide range of slit-like pores (1.8 nm to 70 nm) were formed. As a result, the degradation efficiencies of phenol and humic acid (HA) in 10 min were increased by 150 % and 240 %, respectively. This was attributed primarily to the synergistic effect of the electron-enriched nitrogen sites which functioned as active sites for PMS activation and the interlayer-expanded mesoporous structure, thanking to which that more active sites were exposed and the internal diffusion was also improved. Quenching experiment, electron paramagnetic resonance and linear sweep voltammetry tests suggested that phenol and HA were degraded mainly through the non-radical pathway, in which the singlet oxygen (1O2) was the key reactive species. This study provides a simple method to fabricate an efficient graphene-based catalyst for PMS activation, and will be useful for further development of persulfate-based advanced oxidation process.

Scalable synthesis and electrochemical performance of mesoporous graphene from calcium carbonate by magnesiothermic reaction

A novel scalable synthetic method of mesoporous graphene has been developed using the compressed mixture of Mg and excess CaCO3 in a closed container. The generated solid oxide and unreacted CaCO3 could act as mesopore-forming agents, and the closed container could prevent the carbon dioxide from CaCO3 flow away. As a result, the graphenes with a large number of 2–30 ​nm mesopores and high utilization ratio of Mg achieved. The graphenes had high specific surface area and excellent electrochemical performance. In particular, the Mg utilization ratio was up to 53.3% in the preparation of graphene using 2:1 CaCO3/Mg at 700 ​°C, which is superior to previous researches. The obtained mesoporous graphene exhibited high specific surface area of 743.7 ​m2 ​g-1, large specific capacitance of 140 ​F ​g-1, and high capacitance retention rate of 64.3%.