Catalysts play a crucial role in water electrolysis by reducing the energy barriers for hydrogen and oxygen evolution reactions (HER and OER). Research aims to enhance the intrinsic activities of potential catalysts through material selection, microstructure design, and various engineering techniques. However, the energy consumption of catalysts has often been overlooked due to the intricate interplay among catalyst microstructure, dimensionality, catalyst-electrolyte-gas dynamics, surface chemistry, electron transport within electrodes, and electron transfer among electrode components.
View Article and Find Full Text PDFRecent Adv Drug Deliv Formul
October 2022
The term "reactive oxygen species" (ROS) refers to a family of extremely reactive molecules. They are crucial as secondary messengers in both physiological functioning and the development of cancer. Tumors have developed the ability to survive at elevated ROS levels with significantly higher H2O2 levels than normal tissues.
View Article and Find Full Text PDFThe application of nanoparticulate therapies for cancer depends largely on the uptake and redox activity of the particles. The present work reports the fabrication of different morphologies of nanoceria (CeO) as nanooctahedra (NO), nanorods (NR), and nanocubes (NC) by hydrothermal synthesis at different temperatures (100 °C, 180 °C) of solutions of 0.05 M Ce(NO)·6HO and different concentrations of NaOH (0.
View Article and Find Full Text PDFThe present work reports a detailed mechanistic interpretation of the role of the solubility of dopants and resultant midgap defect energies in band gap engineering. While there is a general perception that a single dopant is associated with single solubility and defect mechanisms, in reality, the potential for multiple solubility and defect mechanisms requires a more nuanced interpretation. Similarly, Kröger-Vink defect equilibria assume that stoichiometries during substitutional and interstitial solid solubility as well as Schottky and Frenkel pair formation are compensated by the diffusion of matrix ions to the grain boundaries or surface.
View Article and Find Full Text PDFCe/Cr codoped TiO nanoparticles were synthesized using sol-gel and Pechini methods with heat treatment at 400 °C for 4 h. A conventional sol-gel process produced well-crystallized anatase, while Pechini synthesis yielded less-ordered mixed-phase anatase + rutile; this suggests that the latter method enhances Ce solubility and increases chemical homogeneity but destabilizes the TiO lattice. Greater structural disruption from the decomposition of the Pechini precursor formed more open agglomerated morphologies, while the lower levels of structural disruption from pyrolysis of the dried sol-gel precursor resulted in denser agglomerates of lower surface areas.
View Article and Find Full Text PDFStatement Of Problem: Yttria-stabilized tetragonal zirconia polycrystal has been used as a dental biomaterial for several decades because the fracture toughness and bend strength are increased by a stress-induced transformation-toughening mechanism. However, its esthetics are compromised by its poor translucency and grayish-white appearance.
Purpose: The purpose of the present systematic review was to assess information on the mechanical, chemical, and optical requirements of monolithic zirconia dental restorations.
Since there is increasing concern for the impact of air quality on human health, the present work surveys the materials and technologies for air purification using photocatalytic materials. The coverage includes (1) current photocatalytic materials for the decomposition of chemical contaminants and disinfection of pathogens present in air and (2) photocatalytic air purification systems that are used currently and under development. The present work focuses on five main themes.
View Article and Find Full Text PDFThe present work reports data for the mineralogical and chemical properties of anatase thin films individually doped or codoped with chromium and vanadium, fabricated by sol-gel spin coating on glass substrates and annealing at 450 °C for 2 h. X-ray photoelectron spectroscopy data indicated the presence of Ti(4+), Ti(3+), Cr(3+), and possibly Cr(4+) in the Cr-doped thin films; Ti(4+), Ti(3+), V(3+), V(4+), and possibly V(5+) in the V-doped thin films; and Ti(4+), Ti(3+), Cr(3+), Cr(4+), V(3+), V(4+), and possibly V(5+) in the codoped thin films. While the thermodynamically stable valences Ti(4+), Cr(3+), and V(5+) would be expected to have formed, the presence of the nonequilibrium valences Ti(3+), Cr(4+), V(3+), and V(4+) is considered to have resulted from intervalence charge transfer for the Cr-doped and V-doped systems but from multivalence charge transfer (MVCT) for the codoped system.
View Article and Find Full Text PDFJ Biomed Mater Res B Appl Biomater
April 2012
The present work examines the chemistry, microstructure, and crystallography of a Pt-Al(2)O(3) joint used in implantable hermetic feedthrough designs in neural prostheses. Pt was joined to Al(2)O(3) by passing Pt pins through green Al(2)O(3) disks and then sintering in air. This created a Pt-Al(2)O(3) joint that was prepared for the current investigation by gross sectioning and then polishing and sectioning into slices using focused ion beam milling.
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