Multi-Functional Materials Based on Cu-Doped TiO2 Ceramic Fibers with Enhanced Pseudocapacitive Performances and Their Dielectric Characteristics

Abstract

In this work, pure TiO2 and Cu (0.5, 1, 2%)-doped TiO2 composites prepared by electrospinning technique followed by calcination at 900 °C, and having high pseudocapacitive and dielectric characteristics were reported. These nanocomposites were characterized by scanning electron microscopy, X-ray diffraction, and dynamic water sorption vapor measurements. The structural characterization of these nanostructures highlighted good crystallinity including only the rutile phase. The electrochemical characteristics were investigated by cyclic voltammetry and galvanostatic charge–discharge measurements, which were performed in a KOH electrolyte solution. Among the Cu-doped TiO2 nanostructures that were prepared, the one containing 0.5% Cu exhibited superior electrochemical properties, including high specific gravimetric capacitance of 1183 F·g−1, specific capacitance of 664 F·g−1, energy density of 45.20 Wh·kg−1, high power density of 723.14 W·kg−1, and capacitance retention of about 94% after 100 cycles. The dielectric investigation shows good dielectric properties for all materials, where the dielectric constant and the dielectric loss decreased with the frequency increase. Thus, all the interconnected studies proved that these new materials show manifold ability and real applicative potential as pseudocapacitors and high-performance dielectrics. Future work and perspectives are anticipated for characterizing electrochemical and dielectric properties for materials including larger amounts of Cu dopant.

Multicomponent Photocatalytic-Dispersant System for Oil Spill Remediation

“…This means that the larger the area ( A ) in the CV curves, the greater the capacitance ( C ). From Figure a,b, it can be deduced that HNT-Ag-TiO 2 -LT80, Ag-TiO 2 , and HNT-Ag-TiO 2 had higher capacitance than TiO 2 . A large conductivity is associated with high capacitance which also correlates to a higher number of effective charges .…”

“…101−103 The oxidation and reduction peaks are indicative of the interconversion of the Ti 2+ and Ti 4+ of the TiO 2 and for the rest of the composites it was between that of the Ti and Ag. 101,102 The photoexcitation generates electrons and holes in the conduction and valence bands, respectively. The holes in the valence band are able to oxidize substrates such as water or hydroxyl ions to generate hydroxyl radicals which are able to degrade organic compounds like crude oil.…”

“…The cyclic voltammograms in Figure a,b suggest that the HNT-Ag-TiO 2 -LT80, Ag-TiO 2 , TiO 2 , and HNT-Ag-TiO 2 underwent redox reactions through photoexcitation. This means that the TiO 2 and its modified forms (HNT-Ag-TiO 2 -LT80, Ag-TiO 2 , and HNT-Ag-TiO 2 ) can induce reactive oxygen species (ROS) under UV illumination. − The oxidation and reduction peaks are indicative of the interconversion of the Ti 2+ and Ti 4+ of the TiO 2 and for the rest of the composites it was between that of the Ti and Ag. , The photoexcitation generates electrons and holes in the conduction and valence bands, respectively. The holes in the valence band are able to oxidize substrates such as water or hydroxyl ions to generate hydroxyl radicals which are able to degrade organic compounds like crude oil. , …”

Improvements in the Electrochemical Performance of Sodium Manganese Oxides by Ti Doping for Aqueous Mg‐Ion Batteries

“…These slender nanowires provide a path for the rapid transportation of magnesium ions and improve the dynamic performance of magnesium ions. At the same time, the gap between the wires and the particles attached to the surface also provide many active sites for the insertion and extraction of magnesium ions, In addition, we tested that the tap density of NMO and NMTO-5 materials is 1.804 and 1.423 g/cm 3 , respectively, which also confirms that NMTO-5 has a larger specific surface area, thus improving the transport capacity of magnesium ions under high current density. [37] With the further increase of the doping content, the nanowires gradually become shorter, and the number of nanosheets begins to increase.…”

“…It can effectively solve the short range of electric vehicles, the large output fluctuations of wind power plants, and "peak shaving and valley filling" faced by smart grids . [3][4] At present, lithium-ion batteries are widely used in various electronic devices due to their small volume, high performance, and portability. [5][6] However, hidden dangers such as dendrite growth, overcharge and over discharge of lithium-ion batteries, and inflammable and explosive organic electrolytes frequently occur.…”