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The response and recovery of a graphene-based sensor for nitrogen dioxide (NO) sensing is improved by a combination of two treatments including rapid thermal annealing (RTA) of graphene and UV illumination during the pump down period. A two-dimensional monolayer graphene grown by chemical vapor deposition was transferred to an arc-shape electrode and subsequently heated at temperatures from 200 to 400 °C for 1 min in N atmosphere by RTA to eliminate the chemical residues on the graphene generated in the transfer process. The effect of RTA and poly(methyl methacrylate) (PMMA) residues was investigated using Raman spectroscopy. The shift of the G and 2D bands could be due to graphene suffering from compressive strain and hole doping from the substrate enhanced by the RTA treatment. The hole doping effect was also observed from Hall measurements. Atomic force microscopy images confirm the PMMA residues and surface roughness reduction by the RTA treatment. Annealing at 300 °C enhances the NO sensing response at 1 ppm by 4 times compared to the pristine graphene without RTA. Full recovery of the sensor to the initial baseline could be achieved by the adjustment of UV illumination time.
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http://dx.doi.org/10.1039/c9ra01295h | DOI Listing |
BMC Oral Health
May 2025
Prosthodontics Department, College of Dentistry, Ibb University, Ibb, 70270, Yemen.
Background: This review aimed to address the growing interest in recycling dental zirconia residues, which are a significant byproduct of the CAD/CAM milling process, contributing to environmental and economic concerns. Further, the review evaluates the potential applications of recycled zirconia in dentistry.
Methods: This scoping review followed PRISMA-ScR guidelines.
Food Chem
July 2025
College of Chemistry and Chemical Engineering, Liaocheng University, Liaocheng 252059, China. Electronic address:
Food contamination is a current global concern, thus rapid and accurate quantitative detection of contaminants is essential for ensuring food safety. Herein, a MOF-based mixed-matrix membrane (1@PMMA) was fabricated by incorporating a stable 2D luminescent Cd-MOF, {[Cd(L)(DMSO)]·2DMSO} (1) (HL = 5-(4-(pyridin-4-yl)benzamido)benzene-1,3-dioic acid), into a flexible poly(methyl methacrylate) (PMMA) matrix. The resulting 1@PMMA exhibited sensitive, strong anti-interference, recyclable, and visual detection of nitrofurazone (NFZ) and 2,6-dichloro-4-nitroaniline (DCN).
View Article and Find Full Text PDFSci Total Environ
April 2025
Queensland Alliance for Environmental Health Sciences (QAEHS), The University of Queensland, 20 Cornwall Street, Woolloongabba, QLD 4102, Australia; ARC Training Centre for Hyphenated Analytical Separation Technologies (HyTECH), Queensland Alliance for Environmental Health Sciences (QAEHS), The Univ
Compost and potting mixes have emerged as significant sources of plastic and biodegradable polymer residues in soil. While bio-based (such as polylactic acid (PLA), polyhydroxyalkanoates (PHAs) and polybutylene succinate (PBS)) and fossil-based (such as polycaprolactone (PCL), and polybutylene adipate terephthalate (PBAT)) biodegradable polymers are designed to rapidly degrade and are marketed as biodegradable, they require specific conditions to do so. Consequently, both conventional and biodegradable plastic polymers raise concerns that they may be harming the environment.
View Article and Find Full Text PDFPolymers (Basel)
March 2025
Department of Electrical and Biological Physics, Kwangwoon University, Wolgye-Dong, Seoul 01897, Republic of Korea.
The removal of surface residues from single-layer graphene (SLG), including poly(methyl methacrylate) (PMMA) polymers and Cl ions, during the transfer process remains a significant challenge with regard to preserving the intrinsic properties of SLG, with the process often leading to unintended doping and reduced electronic performance capabilities. This study presents a rapid and efficient surface treatment method that relies on an aqueous sodium nitrite (NaNO) solution to remove such contaminants effectively. The NaNO solution rinse leverages reactive nitric oxide (NO) species to neutralize ionic contaminants (e.
View Article and Find Full Text PDFWaste Manag
March 2025
Génie Chimique, Polytechnique Montréal, 2500 ch. de Polytechnique Montréal, Québec, Canada. Electronic address:
Artificial marble, a composite material consisting of 40 % (g g) Poly Methyl Methacrylate (PMMA) and 60 % (g g) aluminium hydroxide Al(OH)3, combines the durability and aesthetics of real marble with the lightweight and moldability of plastic. It is the most sought-after synthetic stone in the world, with a production volume of over 1 million t in 2021. However, due to a high level of cross-linking, mechanical recycling of the composite is impossible, while chemical recycling is achievable, yet unprofitable.
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