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The coating of the nanoparticles (Nps), in addition to avoiding their agglomeration and degradation in the different media used, provides them with new properties and, therefore, also to the nanocomposite obtained. In this work, new hybrid nanocomposites based on poly(3-hexylthiophene) with Nps of Fe 3 O 4 or Fe 3 O 4 @ZnFe 2 O 4 core@shell are synthesized and characterized. Fe 3 O 4 Nps are obtained by the chemical bath deposition method, while Fe 3 O 4 @ZnFe 2 O 4 core@shell Nps are synthesized by wet chemistry by deposition of ZnO on the surface of Fe 3 O 4 Nps. P3HT/Fe 3 O 4 and P3HT/Fe 3 O 4 @ZnFe 2 O 4 nanocomposites are obtained by in-situ synthesis of P3HT by the Grignard metathesis method (GRIM) in the presence of different concentrations of the Nps (3HT/Fe 3 O 4 or 3HT/Fe 3 O 4 @ZnFe 2 O 4 weight ratio: 1/0.01 and 1/0.02). The incorporation of Fe 3 O 4 and Fe 3 O 4 @ZnFe 2 O 4 in the P3HT polymeric matrix is corroborated by FTIR. With the incorporation of both nanoparticles (Fe 3 O 4 and Fe 3 O 4 @ZnFe 2 O 4) to P3HT, the roughness increased, and the absorbance was increased depending on the concentration of the particles. The presence of Fe 3 O 4 @ZnFe 2 O 4 core@shell Nps in P3HT increases the decomposition temperature, and the photoconductivity. On the other hand, the electrochemical characterization shows an increase in the cycle area when incorporating Fe 3 O 4 @ZnFe 2 O 4 in P3HT. The P3HT/Fe 3 O 4 @ZnFe 2 O 4 nanocomposites obtained in this work present interesting optoelectronic properties to be applied in different optoelectronic devices. • Synthesis of P3HT in presence of Fe3O4 or Fe3O4@ZnFe2O4 core-shell Nps. • Effect of ZnFe2O4 shell in Fe3O4 on the properties of composites with P3HT was studied. • More than 91 % of the HT dyads were achieved in the P3HT/Fe3O4@ZnFe2O4 composites. • Presence of shell contributes to a homogeneous distribution of particles within P3HT. • Fe3O4@ZnFe2O4 increased charge storage, conductivity and photoresponse of composites. [ABSTRACT FROM AUTHOR]

• Several loadings of Ag 2 O nanoparticles deposited on TiO 2 by deposition-precipitation. • High mineralization of iopromide using Ag 2 O/TiO 2 materials under UV-C light irradiation. • >65% of mineralization using 1.15 wt. % Ag 2 O/TiO 2 under visible light irradiation. • Photocatalytic activity reduced in tap water due to the matrix effect. • Intermediaries of photocatalytic degradation were identified by MS. TiO 2 was modified by the deposition of Ag 2 O nanoparticles to increase the photocatalytic degradation of iopromide in water under UV–C (λ = 254 nm) and UV–A/visible light irradiation (380–800 nm) using pure and tap water. Several loadings of Ag 2 O were deposited on TiO 2 , namely 0.03, 0.15, 0.25, 0.65, 1.0, 1.15, 1.35 and 1.8 wt. %. XRD, TEM, BET, ICP-OES, XPS, DRS and cathodoluminescence spectroscopy were carried out to characterize the materials, while semiconducting properties of the composite were elucidated through electrochemical and photoelectrochemical characterization. Under UV–C light irradiation, the Ag 2 O/TiO 2 heterostructures showed higher mineralization of iopromide (up to 86%, using the 1.15 wt. % Ag 2 O/TiO 2 material) than unmodified materials (37% for TiO 2 and 14% for Ag 2 O), indicating a synergistic effect by the combination of both compounds in the composite. Under UV–A/visible light irradiation, mineralization achieved with the 1.15 wt. % Ag 2 O/TiO 2 material decreased up to 65%, which was again higher than that obtained for its single components. Stability of the photocatalyst was observed through three consecutive reaction cycles under UV–A/visible light irradiation. In tap water, environmentally relevant concentrations of iopromide were tested (Co = 50 μg L−1), resulting in a high degradation rate, while mineralization dramatically decreased because of the matrix effect. Some by-products were identified by mass spectroscopy and a possible degradation path was proposed. The outstanding photocatalytic activity of the Ag 2 O/TiO 2 materials was explained by the electron trap effect exerted by Ag 2 O, along with the appearance of different silver species (Ag 2 O, Ag 2 O 2 and Ag°) throughout the photocatalytic reaction, enhancing the mobility of the charge carriers and thus the generation of reactive species on the photocatalyst surface. [ABSTRACT FROM AUTHOR]

In the present work, particles of cobalt hexacyanoferrate (CoHCF) were deposited on reticulated vitreous carbon (RVC) foam surface to overcome the lack of conductivity of CoHCF and take advantage of their capacity for Na+ ions storage. The deposition was carried out through direct formation of the CoHCF by cyclic voltammetry, and the chemical transformation of cobalt hydroxide and cobalt hydroxide carbonate films obtained by electrochemical and hydrothermal synthesis, respectively, to CoHCF by immersion in an aqueous solution containing [Fe(CN) 6 ]3- ions. The prepared composites were characterized through FTIR, Raman, XRD and SEM-EDS techniques to obtain information about their morphology, composition and structure. The results indicated that the employ of RVC foam leads to well-distributed CoHCF particles connected to its surface, offering abundant sites for ion-storage. Moreover, their electrochemical performance was evaluated by cyclic voltammetry (CV), galvanostatic charge-discharge (GCD) and electrochemical impedance spectroscopy (EIS). Benefiting from the highly conductive substrate, the charge storage mechanism of CoHCF and RVC, and the lower impedance originated at the CoHCF/RVC interface, the composites exhibited an enhanced performance at high potential scan rates or charge and discharge rates. Notably, improved electrochemical utilization of CoHCF was reached through the methods based on cobalt precursors, such composites displayed higher storage capacity. The CoHCF(-1.1 V)/RVC electrode synthesized by electrochemical-chemical synthesis exhibits a high specific capacity of 816 mC cm−3 at 0.25 mA cm−3 and 36% (296 mC cm−3) of its initial capacity was maintained at 5 mA cm−3, which improves 2.8 times the capacity achieved by CoHCF(50 mVs−1)/RVC through electrochemical strategy and the 19% of capacity retention from CoHCF(1 mmol)/RVC composite prepared by the hydrothermal-chemical method. Therefore, the CoHCF(-1.1 V)/RVC electrode can be potentially employed as a cathode in the recent sodium-ion batteries technology. [Display omitted] • CoHCF-RVC composites were synthesized by electrodeposition of CoHCF films and by the chemical etching cobalt hydroxides precursors. • In the composites, RVC improves the electronic conductivity and CoHCF provides sites for electrochemical Na-ion storage. • The utilization of Co-based precursors leads to high performance composites in terms of storage capacity. • The E-C(-1.1) composite exhibited a high specific capacity of 816.71 mC cm−3 at 0.25 mA cm−3 in 0.5 M Na 2 SO 4. [ABSTRACT FROM AUTHOR]