\{We report the preparation and spectro-electrochemical characterization of electrochromic devices (ECD) combining inkjet-printed WO3 as cathode and electro-deposited V2O5 as anode. ECD were prepared for the first time with an optimized formulation of gel polymer electrolyte based on Bisphenol A ethoxylate dimethacrylate and Poly(ethylene glycol) methyl ether methacrylate (BEMA/PEGMA) encompassing the Room Temperature Ionic Liquid (RTIL, 1-Ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide) as solvent. The UV-VIS spectrum of ECD was recorded at different potentials during Li+ insertion and de-insertion; additionally the Percent Trasmittance (T%) of ECD vs. time was investigated during repeated bleaching and coloring cycles allowing thus the estimation of switching times and device stability. Due to the lower ionic conductivity and the apparent superior solvent permeability within WO3 active layer, RTIL containing ECD showed slower switching times, but higher contrast with respect to the similar ones with EC/DEC as solvent. These results indicate that the ECD containing environment-friendly RTIL electrolytes are suitable for applications requiring high contrast, high safety and moderately fast switching times.\}

Zinc oxide (ZnO) is a widely studied wide band gap semiconductor with applications in several fields, namely to enhance solar cells efficiency. Its ability to be grown in a wide variety of nanostructured morphologies, allowing the designing of the surface area architecture constitutes an important advantage over other semiconductors. Laser assisted flow deposition (LAFD) is a recently developed growth method, based on a vapour-solid mechanism, which proved to be a powerful approach in the production of ZnO micro/nanostructures with different morphologies as well as high crystallinity and optical quality. In the present work we report the use of the LAFD technique to grow functional ZnO nanostructures (nanoparticles and tetrapods) working as nano templates to improve the dye-sensitized solar cells (DSSCs) efficiency. The structural and morphological characterization of the as-grown ZnO crystals were performed by X-ray diffraction and electron microscopy, respectively, and the optical quality was assessed by photoluminescence spectroscopy. DSSCs were produced using a combination of these nanostructures, which were subsequently sensitized with N719 dye. An efficiency of ∼3{%} was achieved under simulated AM 1.5 illumination conditions for a dye loading time of 1 h.

\{pH is a vital physiological parameter that can be used for disease diagnosis and treatment as well as in monitoring other biological processes. Metal/metal oxide based pH sensors have several advantages regarding their reliability, miniaturization, and cost-effectiveness, which are critical characteristics for in vivo applications. In this work, WO3 nanoparticles were electrodeposited on flexible substrates over metal electrodes with a sensing area of 1 mm(2). These sensors show a sensitivity of -56.7 +/- 1.3 mV/pH, in a wide pH range of 9 to 5. A proof of concept is also demonstrated using a flexible reference electrode in solid electrolyte with a curved surface. A good balance between the performance parameters (sensitivity), the production costs, and simplicity of the sensors was accomplished, as required for wearable biomedical devices.\}

Flow electrode capacitive deionization (FCDI) is a desalination technology employing flowable carbon slurries to remove salt from an influent through the electro-sorption of ions at the surface of pores of activated carbon particles. This study presents an extensive morphological, electrochemical and rheological analysis of flow electrodes prepared using commercial (YP50F, YP80F, Norit, PAC) and lab-synthesized (KUA, PAC-OX) activated carbons. Simultaneous optimization of particle size, surface area, and surface chemistry of activated carbons is essential to enhance desalination efficiency in FCDI applications. The lab-made highly microporous activated carbon (KUA), prepared from a Spanish anthracite, exhibited a remarkably high specific surface area ( 2800 m2/g) but required first a particle size reduction through ball milling (from 56 μm to 12 μm) for the respective flow electrodes to achieve flowability. The slurry of milled fine KUA (designated as KUAF) shows a specific capacitance of 55 F/g, a 38-fold increase compared to its pristine form. The KUA-F flow electrode also achieved a maximum salt adsorption capacity of 185 mg/g, outperforming the leading commercial alternative (YP80F) by 26 %. The FCDI cell with the KUA-F flow electrode exhibited a desalination efficiency of 79 % at 15 wt% loading, surpassing YP80F by 29 %. In contrast, using PAC-OX (oxidized form of PAC), despite increasing oxygen functional groups and with relatively higher specific surface area, led only to a 2 % improvement in desalination performance, highlighting that oxidation alone at larger particle sizes and broader distribution is insufficient.

Electroactive bacteria mediate electron exchange with external compounds through a process known as extracellular electron transfer (EET). A key step in EET is the transfer of electrons from the menaquinone pool to inner membrane-associated quinol-cytochrome c oxidoreductase complexes, which subsequently relay electrons to periplasmic redox partners. Gene-knockout and proteomic analyses have identified several critical components involved in EET in Geobacter sulfurreducens, including six inner membrane oxidoreductase gene clusters. Of these, three – CbcL, ImcH, and CbcBA - have been linked to specific respiratory pathways depending on the redox potential of the terminal electron acceptor. Cbc4 is one of the other inner membrane oxidoreductase complexes and is composed by three domains: a membrane-anchored tetraheme c-type cytochrome (CbcS), an iron–sulfur protein containing four [4Fe4S] clusters (CbcT), and an integral membrane subunit (CbcU). In this study, the sequence and AlphaFold model of CbcS were analyzed and its cytochrome domain was produced, and structurally and functionally characterized using Nuclear Magnetic Resonance spectroscopy. CbcS has four bis-histidine low-spin hemes and the structure of its hemecore is homologous to CymA and NrfH from Shewanella and Desulfovibrio species, respectively, despite differences on its axial ligands. Potentiometric titrations showed that the redox active window of CbcS overlaps with those of its putative redox partners of the triheme periplasmic cytochrome family (PpcA-E). However, NMR-monitored electron transfer experiments revealed that CbcS can transfer electrons to PpcA through the heme group closer to the C-terminal (heme IV). Together, these findings provide insights on a putative new respiratory pathway in G. sulfurreducens.

The development of sustainable protein sources is imperative for addressing the global challenge of food/feed security. Microalgae, which may be sustainably cultivated, are a promising source of proteins, gaining a progressive acceptance among consumers. The purpose of this work is to study the recovery of the protein C-phycocyanin from the microalga Arthrospira platensis (Spirulina), using a biphasic extraction system composed of sustainable solvents. The extraction system studied involves a feed phase, consisting of an aqueous salt solution and the target protein, and an extracting phase composed of a Natural Deep Eutectic Solvent (NADES) with affinity to the target protein. The performance of a specific NADES depends on the characteristics of the components of the NADES, in terms of its hydrophobicity/hydrophilicity balance, aiming the highest possible partitioning coefficient towards C-phycocyanin. It is also important to assure that the NADES phase selected presents a moderate viscosity and leads to a stable interface when in contact with the aqueous feed phase (i.e., presenting a measurable interfacial tension). In this work, after an extensive screening work of more than 71 combinations, the most overall performing combination is presented. This system shows a high partitioning coefficient of 29.4 ± 0.3 and an extraction yield of 99 % for C-phycocyanin (C-PC), demonstrating that the salting-out effect of the phosphate buffer and the hydrophobic character of NADES play a key role in this protein partitioning and recovery.