Efficient heterogeneous catalysis of hydrogen oxidation reaction (HOR) by platinum group metal (PGM)-free catalysts in proton-exchange membrane (PEM) fuel cells represents a significant challenge toward the development of a sustainable hydrogen economy. Here, we show that graphene acid (GA) can be used as an electrode scaffold for the noncovalent immobilization of a bioinspired nickel bis-diphosphine HOR catalyst. The highly functionalized structure of this material and optimization of the electrode-catalyst assembly sets new benchmark electrocatalytic performances for heterogeneous molecular HOR, with current densities above 30 mA cm at 0.4 V versus reversible hydrogen electrode in acidic aqueous conditions and at room temperature. This study also shows the great potential of GA for catalyst loading improvement and porosity management within nanostructured electrodes toward achieving high current densities with a noble-metal free molecular catalyst.
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http://dx.doi.org/10.1021/acsami.9b18922 | DOI Listing |
Nat Commun
December 2024
Department of Chemical Engineering, Electrochemical Innovation Lab, University College London, London, UK.
High-temperature proton exchange membrane fuel cells (HT-PEMFCs) offer solutions to challenges intrinsic to low-temperature PEMFCs, such as complex water management, fuel inflexibility, and thermal integration. However, they are hindered by phosphoric acid (PA) leaching and catalyst migration, which destabilize the critical three-phase interface within the membrane electrode assembly (MEA). This study presents an innovative approach to enhance HT-PEMFC performance through membrane modification using picosecond laser scribing, which optimises the three-phase interface by forming a graphene-like structure that mitigates PA leaching.
View Article and Find Full Text PDF3D Print Addit Manuf
December 2024
Materials Science and Technology Center (CCTM), Nuclear, and Energy Research Institute (IPEN), University of São Paulo (USP), São Paulo, São Paulo, Brazil.
This study describes a 3D fused deposition modeling (FDM) printing process using a graphene-impregnated polylactic acid (G-PLA) filament to create a new type of rigid, plastic, nonconductive, and anticorrosion layer. Therefore, the possibility of 3D printing a plastic layer using FDM methods is demonstrated herein. A commercial magnet such as N35 NdFeB can be used to produce an efficient shielding film by additive manufacturing.
View Article and Find Full Text PDFFood Chem
December 2024
Food Engineering Technology Research Center/Key Laboratory of Henan Province, College of Food Science and Technology, Henan University of Technology, Lianhua Street, Zhengzhou 450001, China. Electronic address:
Most of the excessive aflatoxins in peanut oil are present at lower levels, and few photocatalysts have been reported for degrading low concentrations of aflatoxin B (AFB). This study employed aptamer-modified magnetic graphene oxide/titanium dioxide (MGO/TiO-aptamer) photocatalysts to degrade low concentrations of AFB in peanut oil, thoroughly investigating their selective efficiency, degradation mechanism, and product toxicity. The results indicated that the modification of aptamers on the surface of photocatalytic materials can enhance the selectivity of photocatalysts for AFB in peanut oil.
View Article and Find Full Text PDFAnal Biochem
December 2024
Pharmaceutical Analytical Chemistry Department, Faculty of Pharmacy, Al-Azhar University, 11751, Nasr City, Cairo, Egypt. Electronic address:
Magnesium is an essential mineral in biological systems and has a significant impact on brain health. Its deficiency has been found to correlate with irregular metabolic processes and neurodevelopmental disorders. The objective of this research was to establish and validate an analytical approach based on the standard addition methodology for determining endogenous magnesium levels in the serum of autistic and healthy children.
View Article and Find Full Text PDFNanomaterials (Basel)
December 2024
High-Power Converter Systems (HLU), Technical University of Munich (TUM), 80333 Munich, Germany.
In this paper, a new label-free DNA nanosensor based on a top-gated (TG) metal-ferroelectric-metal (MFM) graphene nanoribbon field-effect transistor (TG-MFM GNRFET) is proposed through a simulation approach. The DNA sensing principle is founded on the dielectric modulation concept. The computational method employed to evaluate the proposed nanobiosensor relies on the coupled solutions of a rigorous quantum simulation with the Landau-Khalatnikov equation, considering ballistic transport conditions.
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