A new method of modifying TiO2 photocatalysts with SiO2 is developed in which SiO2 nanoparticles are simply mixed with TiO2 in water under ambient conditions. This method does not require the use of toxic solvents or significant energy input. Although the SiO2 modification slightly reduces hydroxyl free radical production, the composite SiO2-TiO2 nanomaterials have markedly higher photocatalytic inactivation rates for a common surrogate virus, bacteriophage MS2 (up to 270% compared to the unmodified TiO2), due to the greatly improved adsorptive density and dark inactivation of MS2. The Langmuir isotherm describes the adsorption data well and shows that the TiO2 modified with 5% SiO2 has a maximum adsorption density qmax 37 times that of the unmodified TiO2. The Langmuir-Hinshelwood model fits the photocatalytic inactivation kinetic data well. The SiO2-TiO2 material produces a greater maximum initial inactivation rate yet a lower intrinsic surface reaction rate constant, consistent with the reduced hydroxyl radical production and enhanced adsorption. These results suggest that modifying photocatalyst surface to increase contaminant adsorption is an important strategy to improve photocatalytic reaction efficiency. Simple and cheap synthesis methods such as that used in this study bring photocatalysis closer to being a viable water treatment option.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/es400196p | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Computational exploration of the electrochemical oxidation mechanism of thiocyanate catalyzed by cobalt-phthalocyanines.
Phys Chem Chem Phys
January 2025
Departamento de Química, Facultad de Ciencias, Universidad de Chile, P. O. Box 653, Las Palmeras 3425, Ñuñoa, Santiago, Chile.
In this study, we focused on the mechanism of the electrocatalytic oxidation of thiocyanate, which in traditional electrodes typically requires high overpotentials. As models for reducing these overpotentials and catalyzing the reaction, we used a set of modified cobalt phthalocyanines (CoPc), known as electrocatalysts. Using DFT calculations, we explored how modifications to CoPc by adding electron-donating and withdrawing groups and the coordination of 4-amino thiophenol impact the oxidation process.
View Article and Find Full Text PDFOxygen-Driven Atom Transfer Radical Polymerization.
J Am Chem Soc
January 2025
State Key Laboratory of Molecular Engineering of Polymers, Department of Macromolecular Science, Fudan University, Shanghai 200438, China.
In traditional atom transfer radical polymerization (ATRP), oxygen must be meticulously eliminated due to its propensity to quench radical species and halt the polymerization process. Additionally, oxygen oxidizes the lower-valent Cu catalyst, compromising its ability to activate alkyl halides and propagate polymerization. In this study, we present an oxygen-driven ATRP utilizing alkylborane compounds, a method that not only circumvents the need for stringent oxygen removal but also exploits oxygen as an essential cofactor to promote polymerization.
View Article and Find Full Text PDFCopper-Catalyzed Successive Radical Reactions of Glycine Derivatives.
Org Lett
January 2025
Gansu International Scientific and Technological Cooperation Base of Water-Retention Chemical Functional Materials, Key Laboratory of Eco-Environment-Related Polymer Materials Ministry of Education, College of Chemistry and Chemical Engineering, Northwest Normal University, Lanzhou, Gansu 730070, China.
Here, we present a three-component successive radical addition strategy for the preparation of complex noncanonical α-amino acids from easily available glycine derivatives, alkenes, and aryl sulfonium salts via a copper-catalyzed photoredox-neutral catalytic cycle. The utility of this method is further demonstrated by its application in late-stage site-selective modifications of glycine residues in short peptides. It is worth noting that only 1 mol % copper catalyst is required in this reaction, demonstrating high catalytic efficiency.
View Article and Find Full Text PDFPhotodegradation of naphthalene-derived particle oxidation products.
Environ Sci Atmos
January 2025
Université Claude Bernard Lyon1, CNRS, IRCELYON, UMR 5256 69100 Villeurbanne France.
While photochemical aging is known to alter secondary organic aerosol (SOA) properties, this process remains poorly constrained for anthropogenic SOA. This study investigates the photodegradation of SOA produced from the hydroxyl radical-initiated oxidation of naphthalene under low- and high-NO conditions. We used state-of-the-art mass spectrometry (MS) techniques, including extractive electrospray ionization and chemical ionization MS, for the in-depth molecular characterization of gas and particulate phases.
View Article and Find Full Text PDFValidation of clinical T stages and of prognostic negative markers in patients with muscle invasive bladder cancer: data in the Swedish National Bladder Cancer Registry data from a detailed research database.
Transl Androl Urol
December 2024
Department of Diagnostics and Intervention, Umeå University, Umeå, Sweden.
Background: A previously published study at Norrland University Hospital, Umeå, Sweden, found that in 29.5% of patients with urinary bladder cancer (UBC) who underwent cystectomy, incorrect cT-stage (clinical T-stage) was registered in the Swedish National Register of Urinary Bladder Cancer (SNRUBC). Tumor in bladder diverticulum (TIBD) and tumor-associated hydronephrosis (TAH) were common causes for misclassification.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!