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Carbon capture is amongst the key emerging technologies for the mitigation of greenhouse gases (GHG) pollution. Several materials as adsorbents for CO2 and other gases are being developed, which often involve using complex and expensive fabrication techniques. In this work, we suggest a sound, easy and cheap route for the production of nitrogen-doped carbon materials for CO2 capture by pyrolysis of electrospun poly(acrylonitrile) (PAN) fibers. PAN fibers are generally processed following specific heat treatments involving up to three steps (to get complete graphitization), one of these being stabilization, during which PAN fibers are oxidized and stretched in the 200–300 °C temperature range. The effect of stabilization temperature on the chemical structure of the carbon nanofibers is investigated herein to ascertain the possible implication of incomplete conversion/condensation of nitrile groups to form pyridine moieties on the CO2 adsorption capacity. The materials were tested in the pure CO2 atmosphere at 20 °C achieving 18.3% of maximum weight increase (equivalent to an uptake of 4.16 mmol g−1), proving the effectiveness of a high stabilization temperature as route for the improvement of CO2 uptake. [ABSTRACT FROM AUTHOR]

Keywords: aqueous electrolyte; dye-sensitized solar cell; polyethylene glycol; screen printing; TiO2 EN aqueous electrolyte dye-sensitized solar cell polyethylene glycol screen printing TiO2 6459 6459 1 12/21/20 20201217 NES 201217 B The Cover Feature b shows a modern building powered by aqueous solar cells, placed both indoors and outdoors. Aqueous electrolyte, dye-sensitized solar cell, polyethylene glycol, screen printing, TiO2. [Extracted from the article]

Whereas the commercialization of dye-sensitized solar cells (DSSCs) is finally proceeding taking advantage of their low cost and tunable optical features, such as colour and transparency for both indoor and building-integrated applications, the corresponding aqueous counterpart is still at its infancy. As the TiO 2 electrode is a fundamental component for hybrid solar cells, this work investigates the effect of different molecular (α-terpineol, propylene carbonate) and polymeric (polyethylene oxide, polyethylene glycol, carboxymethyl cellulose and xanthan gum) additives that can be introduced into a commercial TiO 2 paste for for screen-printing (or doctor blade). Among all, the addition of polyethylene glycol leads to the best cell performances, with markedly increased short-circuit current density (+18 %) and power conversion efficiency (+48 %) with respect to the pristine (commercial) counterpart. When further explored at different concentration levels, electrodes fabricated from polyethylene glycol-based pastes show different morphologies, thicknesses and performances, which are investigated through (photo)electrochemical, structural, physical-chemical and microscopic techniques., (© 2020 Wiley-VCH GmbH.)

Na-ion batteries (NIBs) are attracting widespread interest as a potentially more convenient alternative to current state-of-the-art Li-ion batteries (LIBs), chiefly for large-scale energy storage from renewables. Developing novel active materials is essential for the deployment of NIBs, especially in terms of negative electrodes that can accommodate the larger sodium ions. We focus on TiO 2 anatase, which has been proposed as a promising anode material for the overall balance of performance, stability and cost. As the exposed crystal facets in different morphologies of nanostructured anatase can affect the electrochemical performances, here we report a theoretical investigation of Na + adsorption and migration through (101), (100) and (001) surface terminations, thus explaining the different activities toward sodiation reported in the literature. Energy barriers computed by means of the CI-NEB method at the DFT+U level of theory show that the (001) surface is the most effective termination for Na + insertion. We also provide a detailed analysis to elucidate that the energy barriers are due to structural modifications of the lattice upon sodiation. From these results we derive new design directions for the development of cheap and effective oxide-based nanostructured electrode materials for advanced NIBs., Competing Interests: There are no conflicts of interest to declare., (This journal is © The Royal Society of Chemistry.)

In the challenging scenario of anode materials for sodium-ion batteries, TiO 2 nanotubes could represent a winning choice in terms of cost, scalability of the preparation procedure, and long-term stability upon reversible operation in electrochemical cells. In this work, a detailed physicochemical, computational, and electrochemical characterization is carried out on TiO 2 nanotubes synthesized by varying growth time and heat treatment, viz. the two most significant experimental parameters during preparation. A chemometric approach is proposed to obtain a concrete and solid multivariate analysis of sodium battery electrode materials. Such a statistical approach, combined with prolonged galvanostatic cycling and density functional theory analysis, allows identifying anatase at high growth time as the TiO 2 polymorph of choice as an anode material, thus creating a benchmark for sodium-ion batteries, which currently took the center stage of the research in the field of energy storage systems from renewables., Competing Interests: The authors declare no competing financial interest.