Fabrication of a Functionalized Bimetallic MOF on MOF Embedded Graphene Oxide for the Removal of Contaminants from Wastewater

Macro-size regenerated cellulose fibres (RCFs) with embedded graphene oxide (GO) were fabricated by dissolving cellulose in a pre-cooled sodium hydroxide (NaOH)/urea solution and regenerated in sulphuric acid (H2SO4) coagulant. Initially, GO was found to disperse well in the cellulose solution due to intercalation with the cellulose; however, this cellulose-GO intercalation was disturbed during the regeneration process, causing agglomeration of GO in the RCF mixture. Agglomerated GO was confirmed at a higher GO content under a Dino-Lite microscope. The crystallinity index (CrI) and thermal properties of the RCFs increased with increasing GO loadings, up to 2 wt.%, and reduced thereafter. Cellulose-GO intercalation was observed at lower GO concentrations, which enhanced the crystallinity and thermal properties of the RCF-GO composite. It was shown that the GO exhibited antibacterial properties in the RCF-GO composite, with the highest bacterial inhibition against E. coli and S. aureus.

The future of solid-state lighting relies on how the performance parameters will be improved further for developing high-brightness light-emitting diodes. Eventually, heat removal is becoming a crucial issue because the requirement of high brightness necessitates high-operating current densities that would trigger more joule heating. Here we demonstrate that the embedded graphene oxide in a gallium nitride light-emitting diode alleviates the self-heating issues by virtue of its heat-spreading ability and reducing the thermal boundary resistance. The fabrication process involves the generation of scalable graphene oxide microscale patterns on a sapphire substrate, followed by its thermal reduction and epitaxial lateral overgrowth of gallium nitride in a metal-organic chemical vapour deposition system under one-step process. The device with embedded graphene oxide outperforms its conventional counterpart by emitting bright light with relatively low-junction temperature and thermal resistance. This facile strategy may enable integration of large-scale graphene into practical devices for effective heat removal.

Graphene oxide-embedded nanocomposite membrane for solvent resistant nanofiltration with enhanced rejection ability

Membrane technology for CO2/H2 separation, especially when using CO2-selective membranes to keep H2 on the high-pressure retentate side, has been considered promising and energy-efficient for further H2 transport and utilization. This work prepared and optimized a CO2-selective membrane based on polyvinylamine (PVAm) with embedded graphene oxide (GO) and grafted GO for CO2/H2 separation. The facilitated transport effect of PVAm enhances CO2 transport, while the GO-based 2D nanosheets bring in a barrier effect to compensate for the high H2 diffusivity. The GO-modified surface with higher CO2 affinity also provides additional CO2 sorption sites. The membranes’ chemical structure, thermal stability, and morphology were characterized. The effects of GO and PVA-GO in the PVAm matrix and optimal loadings of GO or PVA-GO were investigated. Introducing GO into PVAm significantly increased CO2 permeance with a slight increase in CO2/H2 selectivity. While by adding 0.5 wt% PVA-GO, CO2/H2 selectivity significantly increased from 10 to 22. The selective layer thickness also greatly affects CO2/H2 separation. By increasing the coating layer thickness to approx. 11 μm, the CO2/H2 selectivity substantially increased. The separation performances of the studied membrane are far above the current CO2/H2 upper bound.

Polydopamine coated graphene oxide for anticorrosive reinforcement of water-borne epoxy coating

Homogeneous transfer of graphene oxide into photoresist: Fabrication of high surface area three-dimensional micro-arrays by modified photolithography

Synergetic effect of graphene oxide nanosheets embedded in the active and support layers on the performance of thin-film composite membranes

Sponge-like form-stable phase change materials with embedded graphene oxide for enhancing the thermal storage efficiency and the temperature response in transport packaging applications

This paper focuses on the fabrication of a new hybrid polymer composite laminate (HPCL) using biodegradable materials to avoid dumping of waste and has all the desired characteristics as compared to the conventional matrix composites used in various applications such as aerospace, railways cabin, structures, sports equipment, medical field, etc. Utilizing the hand lay-up method and compression molding machine, six layers of Kevlar fiber, banana fiber, and an epoxy-based matrix reinforced with graphene oxide (GO) were fabricated. By altering the stacking order of fibers in which the HPCL were stacked and embedding GO of various weight percentages (0 wt%, 0.25 wt%, 0.50 wt%, 0.75 wt%, and 1 wt%). As a result, it was seen that the best mechanical characteristics were found to be 42.23 MPa interlaminar shear strength, flexural strength, 300.39 MPa tensile strength, and 85.68 hardness were obtained at set C-2 i.e. 0.5 wt% of GO embedded in KKBBKK stacking order. The 0.25 wt% of GO of HPCL of set C-1 yielded the impact strength with the greatest value of 771.6 J m−1. Field emission scanning electron microscopy, energy dispersive x-ray mapping and x-ray diffraction tests were also conducted for validating the homogeneity of the material. All the mechanical properties were enhanced by embedding GO and incorporating stacking order in HPCL. Therefore, HPCL can be used where lightweight material with proper mechanical strength and biodegradability is an important condition for sustainable development.

In-situ growth of Co/Zn bimetallic MOF on GO surface to prepare GO supporting Co@C single-atom catalyst for Hg0 oxidation

Carbon dioxide (CO2) is often found as the main impurity in natural gas, where methane (CH4) is the major component. The presence of CO2 in natural gas leads to several problems such as reducing the energy content of natural gas and cause pipeline corrosion. Thus it must be removed to meet specifications (CO2 ≤ 2 mol%) before the gas can be delivered to the pipeline. In this work, hollow fiber mixed matrix membrane (MMM) were fabricated by embedding graphene oxide (GO) into a polysulfone (PSf) polymer matrix to improve membrane properties as well as its separation performance towards CO2/CH4 gas. The membrane properties were investigated for pristine membrane and mixed matrix membrane filled with filler loading of 0.25%. The synthesized GO and properties of fabricated membranes were characterized and studied using TEM, AFM, XRD, FTIR and SEM respectively. The permeance of pure gases and ideal selectivity of CO2/CH4 gas were determined using pure gas permeation experiment. GO has affinity towards CO2 gas. The nanosheet structure creates path for small molecule gas and restricted large molecule gas to pass through the membrane. The incorporation of GO in PSf polymer enhanced the permeance of CO 2 and CO2/CH4 separation from 64.47 to 86.80 GPU and from 19 to 25 respectively.

Ni/NiO embedded Graphene Oxide (GO): Ni/NiO@GO is synthesized by citric acid assisted Pechini-type method. Structural and morphological characterizations are performed by X-ray powdered diffraction (XRD), field emission scanning electron microscopy (FESEM) and tunneling electron microscopy (TEM). Defects in GO sheets are probed by RAMAN spectroscopy. The temperature variation of dielectric constant (εR) and dielectric loss (tan δ) are investigated in the temperature range 300 − 400 K. Decoration of GO with Ni/NiO nanoparticles enhances its εR by∼55 times. Moreover, its dielectric constant measured at 5 MHz is found to be∼430 times to that of Ni/NiO along with the reduction of dielectric loss by a factor∼0.5. The enhanced dielectric constant makes the composite Ni/NiO@GO a potential candidate for using in ecologically friendly energy storage devices.

High strength graphene oxide/chitosan composite screws with a steel-concrete structure

Layer-by-layer assembly of efficient flame retardant coatings based on high aspect ratio graphene oxide and chitosan capable of preventing ignition of PU foam

Graphene oxide-in-polymer nanofiltration membranes with enhanced permeability by interfacial polymerization