skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Explore Research Products in the PAR
It may take a few hours for recently added research products to appear in PAR search results.


Title: A chemoinformatics approach for the characterization of hybrid nanomaterials: safer and efficient design perspective
In this study, photocatalytic properties and in vitro cytotoxicity of 29 TiO 2 -based multi-component nanomaterials ( i.e. , hybrids of more than two composition types of nanoparticles) were evaluated using a combination of the experimental testing and supervised machine learning modeling. TiO 2 -based multi-component nanomaterials with metal clusters of silver, and their mixtures with gold, palladium, and platinum were successfully synthesized. Two activities, photocatalytic activity and cytotoxicity, were studied. A novel cheminformatic approach was developed and applied for the computational representation of the photocatalytic activity and cytotoxicity effect. In this approach, features of investigated TiO 2 -based hybrid nanomaterials were reflected by a series of novel additive descriptors for hybrid and hybrid nanostructures (denoted as “hybrid nanosctructure descriptors”). These descriptors are based on quantum chemical calculations and the Smoluchowski equation. The obtained experimental data and calculated hybrid-nanostructure descriptors were used to develop novel predictive Quantitative Structure–Activity Relationship computational models (called “nano-QSAR mix ”). The proposed modeling approach is an initial step in the understanding of the relationships between physicochemical properties of hybrid nanoparticles, their toxicity, and photochemical activity under UV-vis irradiation. Acquired knowledge supports the safe-by-design approaches relevant to the development of efficient hybrid nanomaterials with reduced hazardous effects.  more » « less
Award ID(s):
1800476
PAR ID:
10168055
Author(s) / Creator(s):
; ; ; ; ;
Date Published:
Journal Name:
Nanoscale
Volume:
11
Issue:
24
ISSN:
2040-3364
Page Range / eLocation ID:
11808 to 11818
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
More Like this
  1. ; ; ; ; (, RSC Advances)
    The interfacial contact between TiO 2 and graphitic carbon in a hybrid composite plays a critical role in electron transfer behavior, and in turn, its photocatalytic efficiency. Herein, we report a new approach for improving the interfacial contact and delaying charge carrier recombination in the hybrid by wrapping short single-wall carbon nanotubes (SWCNTs) on TiO 2 particles (100 nm) via a hydration-condensation technique. Short SWCNTs with an average length of 125 ± 90 nm were obtained from an ultrasonication-assisted cutting process of pristine SWCNTs (1–3 μm in length). In comparison to conventional TiO 2 –SWCNT composites synthesized from long SWCNTs (1.2 ± 0.7 μm), TiO 2 wrapped with short SWCNTs showed longer lifetimes of photogenerated electrons and holes, as well as a superior photocatalytic activity in the gas-phase degradation of acetaldehyde. In addition, upon comparison with a TiO 2 –nanographene “quasi-core–shell” structure, TiO 2 -short SWCNT structures offer better electron-capturing efficiency and slightly higher photocatalytic performance, revealing the impact of the dimensions of graphitic structures on the interfacial transfer of electrons and light penetration to TiO 2 . The engineering of the TiO 2 –SWCNT structure is expected to benefit photocatalytic degradation of other volatile organic compounds, and provide alternative pathways to further improve the efficiency of other carbon-based photocatalysts. 
    more » « less
  2. ; ; ; ; ; ; ; ; ; ; et al (, Small)
    Abstract Microswimmers are self‐propelled particles that navigate fluid environments, offering significant potential for applications in environmental pollutant decomposition, biosensing, and targeted drug delivery. Their performance relies on engineered catalytic surfaces. Gold nanoclusters (AuNCs), with atomically precise structures, tunable optical properties, and high surface area‐to‐volume ratio, provide a new optimal catalyst for enhancing microswimmer propulsion. Unlike bulk gold or nanoparticles, AuNCs may deliver tunable photocatalytic activity and increased catalytic specificity, making them ideal co‐catalysts for hybrid microswimmers. For the first time, this study combines AuNCs with TiO2/Cr2O3Janus microswimmers, combining the unique properties of both materials. This hybrid system capitalizes on the tuned optical properties of AuNCs and their role as co‐catalysts with TiO2, driving enhanced photocatalytic performance under ultraviolet (UV) excitation. Using motion analysis, it is shown that the AuNC‐microswimmers exhibit significantly greater propulsion and mean squared displacement (MSD) as compared to controls. These findings suggest that the integration of nanoclusters with semiconductor materials enables state of the art, light‐switchable microswimmers. These AuNC‐microswimmer systems may thus offer new opportunities for environmental catalysis and other applications, providing precise control over catalytic and motile behaviors at the microscale. 
    more » « less
  3. ; ; ; ; (, Journal of Materials Chemistry A)
    Metal organic frameworks (MOFs) have emerged as a novel template to develop porous photocatalytic materials for solar fuel conversion. In this work, we report the synthesis, charge separation dynamics, and photocatalytic performance of the TiO 2 /CuO heterostructure derived from mixed-phase MOFs based on Ti and Cu metal nodes, which demonstrates significantly enhanced catalytic activity for the hydrogen evolution reaction (HER) compared to metal oxides derived from single node MOFs. More importantly, using transient absorption spectroscopy, we identified the specific role each component in the heterostructure plays and unravelled the key intermediate species that is responsible for the exceptional photocatalytic activity of the heterostructure. We found that the HER is initiated with ultrafast electron transfer (<150 fs) from the molecular photosensitizer to the conduction band of TiO 2 , where TiO 2 acts as an electron mediator and shuttles the electron to the CuO cocatalyst, facilitating charge separation and ultimately boosting the HER efficiency. These results not only demonstrate the great potential of using mixed-phase MOFs as templates to synthesize mesoporous heterostructure photocatalysts but also provide important insight into the HER mechanism. 
    more » « less
  4. ; ; (, ChemSusChem)
    Abstract Photocatalytic nitrogen fixation has the potential to provide a greener route for producing nitrogen‐based fertilizers under ambient conditions. Computational screening is a promising route to discover new materials for the nitrogen fixation process, but requires identifying “descriptors” that can be efficiently computed. In this work, we argue that selectivity toward the adsorption of molecular nitrogen and oxygen can act as a key descriptor. A catalyst that can selectively adsorb nitrogen and resist poisoning of oxygen and other molecules present in air has the potential to facilitate the nitrogen fixation process under ambient conditions. We provide a framework for active site screening based on multifidelity density functional theory (DFT) calculations for a range of metal oxides, oxyborides, and oxyphosphides. The screening methodology consists of initial low‐fidelity fixed geometry calculations and a second screening in which more expensive geometry optimizations were performed. The approach identifies promising active sites on several TiO2polymorph surfaces and a VBO4surface, and the full nitrogen reduction pathway is studied with the BEEF‐vdW and HSE06 functionals on two active sites. The findings suggest that metastable TiO2polymorphs may play a role in photocatalytic nitrogen fixation, and that VBO4may be an interesting material for further studies. 
    more » « less
  5. ; ; ; ; ; ; (, Heritage Science)
    Abstract Titanium dioxide (TiO2) has been used in numerous paintings since its creation in the early 1920s. However, due to this relatively recent adoption by the art world, we have limited knowledge about the nature and risk of degradation in museum environments. This study expands on the existing understanding of TiO2facilitated degradation of linseed oil, by examining the effect of visible light and crystallographic phase (either anatase or rutile) on the reactivity of TiO2. The present approach is based on a combination of experimental chemical characterization with computational calculation through Density Functional Theory (DFT) modeling of the TiO2-oil system. Attenuated Total Reflection Fourier Transform Infrared Spectroscopy (ATR-FT-IR) enabled the identification of characteristic degradation products during UV and visible light aging of both rutile and anatase based paints in comparison to BaSO4and linseed oil controls. In addition, cratering and cracking of the paint surface in TiO2based paints, aged under visible and UV–vis illumination, were observed through Scanning Electron Microscopy (SEM). Finally, Density Functional Theory (DFT) modeling of interactions between anatase TiO2and oleic acid, a fatty acid component of linseed oil, to form a charge transfer complex explains one possible mechanism for the visible light activity observed in artificial aging. Visible light excitation of this complex sensitizes TiO2by injecting an electron into the conduction band of TiO2to generate reactive oxygen species and subsequent degradation of the oil binder by various mechanisms (e.g., formation of an oleic acid cation radical and other oxidation products). Graphical Abstract 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Save / Share this Record
  • Send to Email