A facile one-step method was developed to fabricate mono-dispersed Fe nanoparticles (Fe NPs) coated with SiO(2) shell by aqueous reduction method combined with modified Stöber method. Borohydride was acted not only as a reductant for iron salt but also as a catalyst for hydrolysis and polycondensation reaction of tetraethylorthosilicate (TEOS), and more importantly, there was no need to use surface primer for the generation of Fe NPs and catalyst NH(4)OH for SiO(2). Both the Fe NPs agglomeration and SiO(2) shell thickness can be controlled through the synthetic conditions. Lower potassium borohydride (KBH(4)) injection speed was preferable to assemble Fe NPs. The SiO(2) shell thickness increased gradually with the increase of TEOS amount. Under the condition of TEOS amount of 0.1mL and KBH(4) injection speed of 5mL/min, 25nm single Fe NP was coated with SiO(2) shell with thickness of about 9nm. The resulting nanoporous SiO(2) shell was proved to allow reactant to reach the Fe NPs while at the same time protect them from aggregation. The reactivity characterization of the SiO(2)-coated Fe nanoparticles (Fe@SiO(2)) showed that both TEOS concentration and KBH(4) injection speed had effect on Cr (VI) degradation ability. The highest removal capacity of Fe@SiO(2) can reach 467mgCr/gFe at an initial Cr (VI) concentration of 70mg/L under pH 6.0±0.1. XPS and TEM results showed that Cr (VI) was converted to nontoxic Cr (III) and the reaction product was completely adsorbed to SiO(2) shell.
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http://dx.doi.org/10.1016/j.scitotenv.2012.01.010 | DOI Listing |
Talanta
December 2024
School of Food and Biological Engineering, Jiangsu University, Zhenjiang 212013, PR China; College of Ocean Food and Biological Engineering, Jimei University, Xiamen 361021, PR China. Electronic address:
Staphylococcus aureus (S. aureus) has been identified as a indicator of food contamination. In this study, a sensitive and accurate biosensor strategy for S.
View Article and Find Full Text PDFSci Rep
December 2024
Department of Petroleum Engineering, Shahid Bahonar University of Kerman, Kerman, Iran.
Because a significant portion of oil remains in carbonate reservoirs, efficient techniques are essential to increase oil recovery from carbonate reservoirs. Wettability alteration is crucial for enhanced oil recovery (EOR) from oil-wet reservoirs. This study investigates the impact of different substances on the wettability of dolomite and calcite rocks.
View Article and Find Full Text PDFNanomaterials (Basel)
December 2024
College of Materials Science and Engineering, Nanjing Tech University, Nanjing 211816, China.
TiC provides a promising potential for high-temperature microwave absorbers due to its unique combination of thermal stability, high electrical conductivity, and robust structural integrity. C@TiC/SiO composites were successfully fabricated using a simple blending and cold-pressing method. The effects of C@TiC's absorbent content and temperature on the dielectric and microwave absorption properties of C@TiC/SiO composites were investigated.
View Article and Find Full Text PDFLangmuir
December 2024
Key Laboratory of Biomedical Information Engineering of Ministry of Education, School of Life Science and Technology, Xi'an Jiaotong University, Xi'an, Shaanxi 710049, China.
Magnetic fluorescent nanomaterials have broad application prospects as taggants in fields such as anticounterfeiting identification, suspicious object tracking, and potential fingerprint recognition in forensic medicine. It is a common method to synthesize magnetic fluorescent composite nanoparticles by preparing a shell on the surface of magnetic particles to load fluorescent materials. In this work, a magnetic fluorescence nanohybrid was synthesized by in situ encapsulation of carbon quantum dots (CQDs) during the preparation of a SiO shell on the surface of FeO nanoparticles.
View Article and Find Full Text PDFChemosphere
December 2024
State Key Laboratory of Featured Metal Materials and Life-Cycle Safety for Composite Structures, School of Resources, Environment and Materials, Guangxi University, Nanning, 530004, Guangxi, China; College of Environmental Science and Engineering, North China Electric Power University, Beijing, 102206, China; Department of Chemistry, Imperial College London, 82 Wood Lane, London, W12 0BZ, UK. Electronic address:
Exploiting solid powder fluorescence holds significant potential in diverse domains including medicine and forensics. Conventional fingerprint detection methods often fall short due to low contrast, sensitivity, and high toxicity. To addressing these challenges, we present a novel method for latent fingerprint detection using fluorescent carbon dots (CDs) encapsulated into conventional or mesoporous SiO colloidal spheres (CD@SiO or CDs@m-SiO) through a surface functionalization-assisted cooperative assembly process.
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