Mono-, few-, and multilayer graphene is explored towards the electrochemical Hydrogen Evolution Reaction (HER). Careful physicochemical characterisation is undertaken during electrochemical perturbation revealing that the integrity of graphene is structurally compromised. Electrochemical perturbation, in the form of electrochemical potential scanning (linear sweep voltammetry), as induced when exploring the HER using monolayer graphene, creates defects upon the basal plane surface that increases the coverage of edge plane sites/defects resulting in an increase in the electrochemical reversibility of the HER process. This process of improved HER performance occurs up to a threshold, where substantial break-up of the basal sheet occurs, after which the electrochemical response decreases; this is due to the destruction of the sheet integrity and lack of electrical conductive pathways. Importantly, the severity of these changes is structurally dependent on the graphene variant utilised. This work indicates that multilayer graphene has more potential as an electrochemical platform for the HER, rather than that of mono- and few-layer graphene. There is huge potential for this knowledge to be usefully exploited within the energy sector and beyond.
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http://dx.doi.org/10.1038/s41598-019-52463-4 | DOI Listing |
Nanotechnology
December 2024
CCTS/DFQM, UFSCar - Campus Sorocaba, Rod. João Leme dos Santos km 110 - SP-264 Bairro do Itinga - Sorocaba CEP 18052-780, Sorocaba, 18052-780, BRAZIL.
Nanomaterials stand out for their exceptional properties and innovative potential, especially in applications that protect against space radiation. They offer an innovative approach to this challenge, demonstrating notable properties of radiation absorption and scattering, as well as flexibility and lightness for the development of protective clothing and equipment. This review details the use of polymeric materials, such as polyimides (PIs), which are efficient at attenuating ultraviolet (UV) radiation and atomic oxygen (AO).
View Article and Find Full Text PDFACS Biomater Sci Eng
December 2024
Department of Chemical and Biomolecular Engineering, University of Notre Dame, Notre Dame, Indiana46556, United States.
Small extracellular vesicles (sEVs) are promising nanocarriers for drug delivery to treat a wide range of diseases due to their natural origin and innate homing properties. However, suboptimal therapeutic effects, attributed to ineffective targeting, limited lysosomal escape, and insufficient delivery, remain challenges in effectively delivering therapeutic cargo. Despite advances in sEV-based drug delivery systems, conventional approaches need improvement to address low drug-loading efficiency and to develop surface functionalization techniques for precise targeting of cells of interest, all while preserving the membrane integrity of sEVs.
View Article and Find Full Text PDFRSC Adv
December 2024
Instituto de Investigaciones en Materiales, Universidad Nacional Autónoma de México UNAM Av. Universidad, C.U. Coyoacán 04510 Ciudad de México Mexico.
The challenge of bone tissue regeneration implies the use of new advanced technologies for the manufacture of polymeric matrices, with 3D printing technology being a suitable option for tissue engineering due to its low processing cost, its simple operation and the wide use of biomaterials in biomedicine. Among the biopolymers used to obtain porous scaffolds, poly(lactic acid) (PLA) stands out due its mechanical and biodegradability properties, although its low bioactivity to promote bone regeneration is a great challenge. In this research, a 3D scaffold based on PLA reinforced with bioceramics such as graphene oxide (GO) and β-tricalcium phosphate (TCP) was designed and characterized by FTIR, XRD, DSC, SEM and mechanical tests.
View Article and Find Full Text PDFNanoscale
December 2024
University of Brasília, Institute of Physics, Brasília, Federal District, Brazil.
The recent synthesis of nitrogen-doped amorphous monolayer carbon (NAMC) opens new possibilities for multifunctional materials. In this study, we have investigated the nitrogen doping limits and their effects on NAMC's structural and electronic properties using density functional-based tight-binding simulations. Our results show that NAMC remains stable up to 35% nitrogen doping, beyond which the lattice becomes unstable.
View Article and Find Full Text PDFACS Omega
December 2024
Institute of Chemical Engineering Sciences, Foundation of Research and Technology-Hellas (FORTH/ICE-HT), Stadiou Street, Platani, Patras 26504, Greece.
In this work, we present a comprehensive protocol for achieving hole doping in graphene through exposure to nitric acid (HNO) vapors. We demonstrate gradual p-type surface doping of CVD-grown graphene on a Si/SiO substrate by thermally depositing nitric acid molecules to form self-assembled charge transfer complexes. Detailed analysis of charge carrier concentration and Fermi energy shifts was conducted using Raman, X-ray and ultraviolet photoelectron spectroscopies (XPS/UPS).
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