Facile kinetics of Li-ion intake causes superior rate capability in multiwalled carbon nanotube@TiO2 nanocomposite battery anodes

Nanotechnology produces hybrids with superior properties than its individual constituents. Here MWCNT@TiO2 composites have been synthesized by controlled hydrolysis of titanium isopropoxide over MWCNT, to be incorporated into Li-ion battery electrodes. Outstanding rate capability of the coated nanotubes is observed in comparison to pristine TiO2. Specific storage capacity as high as 250 mAh g−1 is achieved for the nanocomposite electrode which doubles that encountered for TiO2-based anodes. The mechanism explaining the enhancement in power performance has been revealed by means of electrochemical impedance methods. Although both pristine TiO2 and MWCNT@TiO2 would potentially exhibit comparable specific capacity, the charge transfer resistance for the latter is reduced by a factor 10, implying a key role of MWCNTs to favor the interfacial Li+ ion intake from the electrolyte. MWCNT efficiently provides electrons to the nanostructure through the Ti–C bond which assists the Li+ ion incorporation. These findings provide access to the detailed lithiation kinetics of a broad class of nanocomposites for battery applications

Generación de estados superficiales durante la formación electroforética catódica de películas de TiO2 sobre ito

In the present work TiO2 films were formed over Indium Tin Oxide (ITO) employing cathodic electrophoretic deposition (Cathodic-EPD) and Dr. Blade Technique. The films were characterized by electrochemical techniques in order to compare their electronic properties; as well as, their photoelectrochemical behavior. The electrochemical performance showed by the films, allowed to relate the modification occurring during the Cathodic-EPD, with the partial reduction of TiO2 nanoparticles, generating Ti3+ defects. These trapping states are modifying the electronic properties of the film, and diminishing the transport of the photoelectrogenerated electrons toward ITO

Enhanced photocatalytic activity of TiO2 films by modification with polyethylene glycol

Titanium dioxide porous thin films on the Anatase phase were deposited onto glass slides by the sol-gel method assisted with polyethylene glycol (PEG). The dip-coated films were characterized using scanning electron microscopy (SEM), thermogravimetric analysis (TGA and DTG), UV-visible spectroscopy and X-ray diffraction (XRD). The photocatalytic activity of the films was determined by means of methyl-orange oxidation tests. The resultant PEG-modified films were crack-free and developed a porous structure after calcination at 500 °C. Photo-oxidation tests showed the dependency of catalytic activity of the films on the number of layers (thickness) and porosity, i.e. of the interfacial area

Utilización de electrodos de pasta de carbono para la evaluación fotoelectroquímica de materiales semiconductores: tio2 en soluciones cianuradas

Las técnicas electroquímicas constituyen una herramienta útil para la evaluación de la actividad fotocatalítica de los semiconductores puesto que las reacciones que tienen lugar son de naturaleza redox. Con este fin, preparar electrodos de trabajo resulta de fundamental importancia para obtener resultados confiables y reproducibles. En este trabajo se describe la preparación de electrodos de TiO2-pasta de carbono y su evaluación en la fotoxidación de cianuro mediante las técnicas de voltamperometría, cronoamperometría, resistencia a la polarización lineal y curvas de polarización de Tafel. Los resultados mostraron que este método de preparación de electrodos permite la adecuada evaluación fotoelectroquímica de semiconductores

Utilización de electrodos de pasta de carbono para la evaluación fotoelectroquímica de materiales semiconductores: tio2 en soluciones cianuradas.

The electrochemical techniques constitute a useful tool for the evaluation of the photocatalytic activity of semiconductor materials since the reactions that take place are redox in nature. With this objective, the fabrication of working electrodes becomes very important to get reliable and reproducible results. In this work we describe the preparation of carbon paste electrodes employing TiO2 powder and their electrochemical evaluation in the photoxidation of cyanide by using voltamperometry, chronoamperometry, linear resistance polarization and Tafel polarization curves. The results shown that this simple, fast and cheap method for the fabrication of electrodes allows the electrochemical evaluation of powder semiconductors.Las técnicas electroquímicas constituyen una herramienta útil para la evaluación de la actividad fotocatalítica de los semiconductores puesto que las reacciones que tienen lugar son de naturaleza redox. Con este fin, preparar electrodos de trabajo resulta de fundamental importancia para obtener resultados confiables y reproducibles. En este trabajo se describe la preparación de electrodos de TiO2-pasta de carbono y su evaluación en la fotoxidación de cianuro mediante las técnicas de voltamperometría, cronoamperometría, resistencia a la polarización lineal y curvas de polarización de Tafel. Los resultados mostraron que este método de preparación de electrodos permite la adecuada evaluación fotoelectroquímica de semiconductores

Formation of TiO2 photoanodes by simultaneous electrophoretic deposition of anatase and rutile particles for photoassisted electrolytic copper ions removal

The influence of Anatasa/Rutile ratio on TiO2 films, grown by electrophoretic deposition was studied in the photoassisted electrolytic copper ions removal from cyanide solutions. The proper dispersant dosage allowing the simultaneous electrophoretic deposition of Anatase and Rutile was chosen based on electrokinetic measurements; evidenced by the XRD spectra of the formed films. The evaluation of films photoassisted electrolytic copper ion removal showeds that it is possible to enhance the activity of Anatase films by adding some Rutile exploiting the synergetic interaction between these two materials, achieve by its proper deposition

2022 Roadmap on aqueous batteries

The development of efficient electrochemical energy storage devices is crucial for future renewableenergy management. Aqueous rechargeable batteries (ARBs) are considered to be one of the mostsustainable battery technologies due to their low cost, ease of manufacture, high safety andenvironmental friendliness. However, some tough issues, such as the narrow electrochemicalstability window of water, chemical instability of electrode materials, uncontrollable dendritegrowth and poor cycling lifespan, severely limit the development of high-energy aqueous batterieswith stability and infallible safety. This article mainly summarizes current and future challengesand the advanced science and technology to meet these challenges of various ARBs, such asaqueous Li/Na/K/Mg/Ca/Al/-ion batteries, aqueous flow batteries and photo-responsive batteries.In addition, the potential direction and prospect of the further development of these systembatteries are discussed. Finally, given the various technologies and their associated technicalchallenges, we are motivated to develop a 2022 roadmap on aqueous batterie