In this study, UiO-66-NH2 was synthesized and incorporated with graphene aerosol (UiO-66-NH2/GA) and ethylenediamine functionalized graphene oxide (UiO-66-NH2/GO-NH2). These composites were characterized using infrared spectroscopy, powder X-ray diffraction, ultraviolet–visible light spectroscopy, scanning electron microscope, and energy-dispersive X-ray spectroscopy. UiO-66-NH2/GO-NH2 exhibited 93% adsorption of quinoline in 5 h, UiO-66-NH2 and UiO-66-NH2/GA presented 80.4% and 86.5%, respectively. The high adsorption observed on UiO-66-NH2/GO-NH2 was attributed to the unique electronic properties, and hydrogen bonding between the nitrogen atom of quinoline and NH2- phenyl fragment of UiO-66-NH2, and N–H of ethylenediamine. GO also offered combined strong π–π interactions on its surface, and the oxygen coverage (~ 50%) on GO within the structure is responsible for the formation of strong hydrogen bonds with quinoline. Theoretical calculation suggested that UiO-66-NH2/GO-NH2 presented a more favourable adsorption energy (− 18.584 kcal/ mol) compared to UiO-66-NH2 (− 16.549 kcal/mol) and UiO-66-NH2/GA (− 13.991 kcal/mol). These results indicate that nanocomposites have a potential application in quinoline capture technologies in the process of adsorptive denitrogenation.

Among efforts to improve techniques for the chemical vapor deposition of large-area and high-quality graphene films on transition metal substrates, being able to reliably transfer these atomistic membranes onto the desired substrate is a critical step for various practical uses, such as graphene-based electronic and photonic devices. However, the most used approach, the wet etching transfer process based on the complete etching of metal substrates, remains a great challenge. This is mainly due to the inevitable damage to the graphene, unintentional contamination of the graphene layer, and increased production cost and time. Here, we report the systematic study of an H2 bubbling-assisted transfer technique for graphene films grown on Cu foils, which is nondestructive not only to the graphene film but also to the Cu substrate. Also, we demonstrate the origin of the graphene film tearing phenomenon induced by this H2 bubbling-assisted transfer process. This study reveals that inherent features are produced by rolling Cu foil, which cause a saw-like corrugation in the poly(methyl methacrylate) (PMMA)/graphene stack when it is transferred onto the target substrate after the Cu foil is dissolved. During the PMMA removal stage, the graphene tearing mainly appears at the apexes of the corrugated PMMA/graphene stack, due to weak adhesion to the target substrate. To address this, we have developed a modified heat-press-assisted transfer technique that has much better control of both tearing and the formation of residues in the transferred graphene films.

다양한 장치에 대한 광범위한 의존으로 에너지는 현대 생활에서 중요한 역할을 하고 있다. 전통적인 에너지원은 많은 환경 및 건강 문제를 안고 있어, 환경과 건강에 미치는 영향을 최소화하면서 에너지 수요를 충족할 수 있는 대체 가능 한 에너지원이 시급히 필요하다. 이러한 관점에서 연료전지, 특히 음이온 교환막 연료전지는 고가의 촉매를 사용하지 않는 빠 른 반응속도, 컴팩트한 디자인, 수소 이외의 연료 선택 가능성 및 보다 저렴한 연료의 사용이 가능한 특성으로 인하여 다른 연료전지에 비해 큰 주목을 받고 있다. 그럼에도 이온전도성이 높고 화학적, 기계적으로 안정적인 음이온 교환막의 개발이 부 진한 것이 주요 장애물이 되어 왔고, 그래핀 기반 고분자 복합막이 AEMFC용 전해질막으로 등장하게 되었다. 2D 구조, 높은 기계적 강도, 높은 내화학성 및 표면적과 같은 그래핀의 견고한 구조 및 물리적 특성은 음이온교환막의 성능 개선에 도움이 된다고 보고되고, 그래핀 및 그 유도체를 사용하는 전해질막의 연구가 중요하게 되었으나, 그래핀 재료의 높은 잠재력에도 지 나친 응집 경향으로 나타나는 문제점이 지적되고 있어 그래핀 유도체의 표면 개질은 응집을 완화하고 그래핀이 가지는 잠재 적 성능을 이끌어내는데 꼭 필요하다. 따라서 본 고에서는 그래핀과 유도체의 표면 개질과 연료 전지용 AEM 제조에서 그 역 할에 초점을 맞추어서 논의하고자 한다.

The effect of the laser ablation duration of reduced graphene oxide sheets on their optical properties was studied. After 30 min of ablation, the average lateral size of reduced graphene oxide sheets decreases from 347.4 ± 86.5 nm to 98.8 ± 36.0. The sizes of almost all particles are in the range up to 100 nm, which was confirmed by transmission electron microscopy and dynamic light scattering data. The FTIR spectroscopy data showed that after ablation the intensity of the bands associated with O–H, C–OH and C=O vibrations were noticeably decreased. The optical density and the fluorescence intensity of reduced graphene oxide also depend on the ablation time. After ablation, the reduced graphene oxide fluorescence intensity increased 2–3 times. The fluorescence lifetime decreases both for the first (from 1.36 ns to 0.71 ns) and second (from 6.03 to 3.66 ns) components. A broad band was recorded in the long-lived luminescence spectrum. The long-lived luminescence intensity is higher on 80% for the samples after 30 min of ablation compared to the unablated sample. It was assumed that during laser ablation of reduced graphene oxide a change in the ratio between oxidized and sp2- hybridized carbon occurs. This opens up possibilities for controlling the optical properties of reduced graphene oxide.

Graphene nanoplatelets (GNPs) have garnered significant attention in the field of thermal management materials due to their unique morphology and remarkable thermal conductive properties. Their impressive thermal properties make them an interesting choice of nanofillers with which to produce multifunctional composite materials and a host of other applications whilst their structural and thermal properties significantly improve their target materials or composites. Therefore, this present study reviewed recent advances in the use of GNPs as nanofillers to enhance the thermal conductivity of various materials or composites. The improved thermal conductivity that GNPs impart in composites is also comprehensively compared and discussed. Therefore, this review may reveal hitherto unknown opportunities and pave the way for the production of materials with enhanced thermal applications including electronics, aerospace devices, batteries, and structural reinforcement.

For graphene oxide (GO) composite hydrogels, a two-dimensional GO material is introduced into them, whose special structure is used to improve their properties. GO contains abundant oxygen-containing functional groups, which can improve the mechanical properties of hydrogels and support the application needs. Especially, the unique-conjugated structure of GO can endow or enhance the stimulation response of hydrogels. Therefore, GO composite hydrogels have a great potential in the field of wearable devices. We referred to the works published in recent years, and reviewed from these aspects: (a) structure of GO; (b) factors affecting the mechanical properties of the composite hydrogel, including hydrogen bond, ionic bond, coordination bond and physical crosslinking; (c) stimuli and signals; (d) challenges. Finally, we summarized the research progress of GO composite hydrogels in the field of wearable devices, and put forward some prospects.

Alzheimer's disease (AD) is one of the most common forms of dementia, affecting more than 50 million people globally. The onset of AD is linked to age, smoking, obesity, hypercholesterolemia, physical inactivity, depression, gender, and genetics of an individual. The accumulation of Aβ peptides and neurofibrillary tangles (NFTs) in the brain is one of the critical factors that lead to AD, which is known to disrupt neuronal signaling and causing neurodegeneration. As per the current understanding, inhibiting the accumulation of Aβ peptides and NFTs is crucial in the management/treatment of AD. Latest research studies show that nanoparticles have the potency of improving drug transport across the blood–brain barrier easily. Specifically, graphene quantum dots (GQDs), a type of semiconducting nanoparticles, have been established as effective inhibitors for blocking the aggregation of Aβ peptides. The small size of GQDs allows them to pass through the blood– brain barrier with ease. Moreover, GQDs have fluorescence properties, which can be used to detect the concentration of Aβ in vivo. In recent years, compared to other carbon materials, the low cytotoxicity and high biocompatibility of GQDs, give them an advantage in the suitability and clinical research for AD. In this manuscript, we have discussed the role of different types of nanoparticles in the transportation of encapsulated or co-assembled compound drugs for the treatment of AD and importantly, the role of GQDs in the diagnosis and management/treatment of AD.

One of the promising supercapacitors for next-generation energy storage is zinc-ion hybrid supercapacitors. For the anode materials of the hybrid supercapacitors, three-dimensional (3D) graphene frameworks are promising electrode materials for electrochemical capacitors due to their intrinsic interconnectivity, excellent electrical conductivity, and high specific surface area. However, the traditional route by which 3D graphene frameworks are synthesized is energy- and time-intensive and difficult to apply on a large scale due to environmental risks. Here, we describe a simple, economical, and scalable method of fabricating grafoil (GF) directly into a graphite–graphene architecture. Both synthesizing of a porous structure and functionalization with interconnected graphene sheets can be simultaneously achieved using electrochemically modified graphite. The resultant graphite electrode provides a high capacitance of 140 mF/cm2 at 1 mA/cm2, 3.5 times higher than that of pristine grafoil, keeping 60.1% of its capacitance when the current density increases from 1 to 10 mA/cm2. Thus, the method to produce 3D graphene-based electrodes introduced in the current study is promising for the applications of energy storage devices.