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One of the important environmental challenges of the 21st century is the effective removal of pollutants from the aquatic environment. In this study, electrodeposited manganese oxides (MnyOx) films were applied as visible-light-driven photocatalyst for the removal and mineralization of Tetracycline (TC) antibiotics. The photocatalytic activity of as-deposited and annealed MnyOx was tested at different pH values using LED visible illumination, resulting in 92.4 % of TC mineralization efficiency after 180 min for the best performing manganese oxide. Quenching experiments showed that hydroxyl radicals (radical dotOH) are the main active species responsible for the TC degradation. The photocorrosion of MnyOx has been studied by quantifying the concentration of the dissolved manganese cations during the photocatalytic experiments. By comparing the catalyst mass loss with the % of TC mineralization, we revealed that the degradation of the oxide surface structure is the factor that, more than the photocorrosion, is limiting the photocatalytic activity of MnyOx films. Finally, the photocatalytic mechanism of TC mineralization is proposed based on the detection of the intermediates species of the mineralization process by High-Performance Liquid Chromatography Mass-Spectroscopy. The facile synthesis process and the superior mineralization rate can open up a new approach for the possible large-scale utilization of electrodeposited MnyOx films as an effective visible light photocatalyst.

Complex tunable visible-light-driven Aurivillius-phase-based micro- and nanostructured photocatalysts were fabricated following a novel, scalable, easily implemented sequential process based on electrochemical deposition and thermal treatment. Regarding its novelty, electrochemistry was the primary tool for synthesis, one that constitutes a viable alternative to other complex chemical and physical processes. The parameters of electrodeposition and thermal conditions promoted different nanostructured Bi2MoO6 and Bi2MoO6@Bi2MoO6-x films. The nanostructured homojunction Bi2MoO6@Bi2MoO6-x films obtained after 3 h of calcination showing micro- and nanowire morphology emerged as the most effective photocatalyst for degrading and mineralizing the mono- and multiantibiotic solutions (i.e., tetracycline, ciprofloxacin, and/or levofloxacin), which achieved near-total degradation and exceptionally high mineralization values (>95%) after 180 min of radiation. The materials' proven reusability, low photocorrosion activity, and excellent photocatalytic performance in mineralizing antibiotics can support the implementation of Bi2MoO6@Bi2MoO6-x homojunctions as efficient visible-light photocatalysts under solar radiation.

Building a sustainable future requires new, accessible, economic, and ecological methods of preparing nanostructured materials used in biomedical and environmental applications. In this work, a detailed study on the electrodeposition process of CoNi in a biocompatible deep eutectic solvent (DES) is presented. Alloy plating performed in choline chloride within a urea-based DES allowed us to tailor elemental compositions, morphologies, and size of the deposits based on the plating conditions. Homogeneous, continuous, and needle-shaped deposits were characterized using electrochemical methods and ex-situ characterization techniques. Although the process's electrochemical behavior corresponded to that of normal deposition, applying the most negative potentials produced a co-reduction of the solvent, which favored the incorporation of oxygen species into the deposit. Given the materials' nature, morphology, and composition tailored to the high active surface, the materials were tested as platforms to activate the formation of sulfate radicals from the peroxomonosulfate salt. Results related to the proposed material and preparation method were promising, as, confirmed by the high effectiveness in degrading the antibiotic tetracycline. Altogether, the work showcases a versatile, environmentally friendly route for electrodepositing CoNi in DESs to yield a proactive tool for developing of platforms with catalytic potential.

9 p.-4 fig., Current microtechnologies have shown plenty of room inside a living cell for silicon chips. Microchips as barcodes, biochemical sensors, mechanical sensors and even electrical devices have been internalized into living cells without interfering their cell viability. However, these technologies lack from the ability to trap and preconcentrate cells in a specific region, which are prerequisites for cell separation, purification and posterior studies with enhanced sensitivity. Magnetic manipulation of microobjects, which allows a non-contacting method, has become an attractive and promising technique at small scales. Here, we show intracellular Ni-based chips with magnetic capabilities to allow cell enrichment. As a proof of concept of the potential to integrate multiple functionalities on a single device of this technique, we combine coding and magnetic manipulation capabilities in a single device. Devices were found to be internalized by HeLa cells without interfering in their viability. We demonstrated the tagging of a subpopulation of cells and their subsequent magnetic trapping with internalized barcodes subjected to a force up to 2.57 pN (for magnet-cells distance of 4.9 mm). The work opens the venue for future intracellular chips that integrate multiple functionalities with the magnetic manipulation of cells., This study was financed by the Spanish Government through project MINAHE6 (TEC2017-85059-C3), MINAHE7 (PID2020-115663GB-C3) and FEDER funding. M.I.A. thanks the MCIU for the pre-doctoral Grant (BES-2015-075932) and the University of Granada for the guidance and support within the doctoral program.

Harmful cyanobacterial algal blooms and cyanotoxins currently pose a major threat to global society, one that exceeds local and national interests due to their extremely destructive effects on the environment and human health. In the near future, the formation of harmful cyanobacterial algal blooms and, in turn, cyanotoxins is expected to become widespread, driven by eutrophication and anthropogenic causes such as water pollution and promoted by escalating global temperatures. Such trends, studied since the late 1990s, have attracted increased interest due to (i) the high environmental impact of cyanobacterial blooms and cyanotoxins worldwide, (ii) the ineffective removal of those pollutants by conventional water treatment processes, (iii) the transformational capacity to completely destroy those organic toxins via alternative treatments such as advanced oxidation processes,and (iv) engineering challenges when transitioning toward the treatment of large volumes of water. The global context of this threat thus urges the innovation of simple, sustainable, low-cost strategies and technologies for water decontamination that can be readily implemented worldwide.

The development of feasible micro/nanoplatforms for various biomedical applications requires holistic research that explores scalable synthesis and design pathways and imposes an interdisciplinary integration of materials science, physical, medical, chemical, and biological knowledge. Thanks to their unique characteristics (i.e., structure, large specific surface areas, tuneability, versatility, and integrity), mesoporous materials have emerged as potential candidates for being part of micro/nanoplatforms for therapeutic, monitoring, and diagnostic applications. In this context, Fe-Pt mesoporous materials are excellent candidates to be part of biomedical micro/nanoplatforms, thanks to their chemical nature, structure, and magnetic properties, which endow them with magnetic locomotion, high cargo capability of therapeutic agents inside the mesoporous cavity, and large surface area for surface functionalization. However, the chemical stability in biological media and cytotoxicity of the Fe-Pt mesoporous material (without considering the effects of architecture and shape) are pivotal elements that determine the suitability of these materials for biomedical applications. This work demonstrates the following: (i) the potential of electrochemical deposition, based on the use of block copolymer micellar solutions as electrochemical media, as an easy, inexpensive, and scalable strategy to synthesize mesoporous Fe-Pt components with tunable chemical composition, porosity, magnetism, and shape (in this case films, but other architectures like nanowires can be easily fabricated using simultaneously hard templates); (ii) the excellent corrosion stability, which is comparable to bulk Au, and minimal chemical dissolution in biological media after 160 h of immersion (∼0.88% of Fe and ∼0.0019% of Pt), which confirms the robustness of Fe-Pt; and (iii) negligible cytotoxicity on HaCaT cells (human immortalized keratinocytes), which reinforces the biocompatibility of Fe-Pt mesoporous structures. Also, the presence of Fe-Pt mesoporous films seems to induce a slight increase in cell viability. These results confirm the biocompatibility of Fe-Pt mesoporous films, making them suitable for biomedical applications.

In pursuit of friendlier conditions for the preparation of high-value biochemicals, we developed a catalytic synthesis of -valerolactone by levulinic acid hydrogenation with formic acid as the hydrogen source. Both levulinic and formic acid are intermediate products in the biomass transformation processes. The objective of the work is two-fold; development of a novel approach for milder synthesis conditions to produce -valerolactone and the reduction of the economic cost of the catalyst. Ni-rich Ni-Pt mesoporous nanowires were synthesized in an aqueous medium using a combined hard-soft template-assisted electrodeposition method, in which porous polycarbonate membranes controlled the shape, and the pluronic P-123 copolymer served as the porogen agent. The electrodeposition conditions selected favored nickel deposition and generated nanowires with nickel percentages above the 75 at. %. The increase in deposition potential favored nickel deposition. However, it was detrimental for the porous diameter, because the mesoporous structure is promoted by the presence of the platinum-rich micelles near the substrate, which is not favored at the more negative potentials. The prepared catalysts promoted the complete transformation to -valerolactone in a yield of around 99% and proceeded with the absence of by-products. The couple temperature and reaction time were optimized considering the energy cost. The threshold operational temperature was established at 140 ºC, at which, 120 minutes were sufficient for attaining the complete transformation. Working temperatures below 140 ºC rendered the reaction completion difficult. The Ni78Pt22 nanowires exhibited excellent reusability, with minimal nickel leaching into the reaction mixture, whereas those with higher nickel contents showed corrosion.

Patients with cancer are poorly represented in coronavirus disease 2019 (COVID-19) series, and heterogeneous series concerning hematology patients have been published. This study aimed to analyze the impact of COVID-19 in patients with lymphoma. We present a multicenter retrospective study from 19 centers in Madrid, Spain, evaluating risk factors for mortality in adult patients with COVID-19 and lymphoma. About 177 patients (55.9% male) were included with a median follow-up of 27 days and a median age of 70 years. At the time of COVID-19 diagnosis, 49.7% of patients were on active treatment. The overall mortality rate was 34.5%. Age >70 years, confusion, urea concentration, respiratory rate, blood pressure, and age >65 score ≥2, heart disease, and chronic kidney disease were associated with higher mortality risk (P < 0.05). Active disease significantly increased the risk of death (hazard ratio, 2.43; 95% confidence interval, 1.23-4.77; P = 0.01). However, active treatment did not modify mortality risk and no differences were found between the different therapeutic regimens. The persistence of severe acute respiratory syndrome coronavirus 2-positive polymerase chain reaction after week 6 was significantly associated with mortality (54.5% versus 1.4%; P < 0.001). We confirm an increased mortality compared with the general population. In view of our results, any interruption or delay in the start of treatment should be questioned given that active treatment has not been demonstrated to increase mortality risk and that achieving disease remission could lead to better outcomes.

Preparation of nanostructured materials with highly efficient active area is crucial for advancement in fields of electrocatalytic conversion of energy, energy storage, or biomedicine. In this regard, there are two main challenges in the electrochemical preparation of high-extended surface area of the nanostructures: 1) establishing the optimal potential conditions to enhance the active area while reducing the size of the prepared material and, 2) simultaneously, finding a practice and simple in situ methodology to qualitatively test the increase in the active surface area. Herein, we investigate the cobalt electrodeposition in choline chloride plus urea deep eutectic solvent (DES) and the effect of the DES in the increase of the active surface area of deposited Co films. In situ classical electrochemical techniques, in combination with ex situ characterization techniques, were employed to establish the best potential conditions to obtain metallic Co films with high active surface area. Then, the increase in active area was tested by using different voltammetric methodologies. The increase in intensity of the outer sphere electron transfer was tested as a tool to analyze the superficial change after cobalt deposition. Voltammetric response in organic medium using benzoquinone on Co films and in an aqueous medium using Ru(NH3)6, after covering the Co films with gold via galvanic displacement, was assessed. Later, as alternative method, the active area of the freshly deposited Co films, after superficial modification with Au, was tested by lead underpotential deposition. Lead underpotential deposition on gold is a surface-structure process that indirectly allows the estimation of the increment in active area of prepared Co films.

Highly efficient, long-term, eco-friendly catalysts for water decontamination technology are urgently needed to meet the prioritized objectives of green development and societies worldwide. Ca-doped ZnO was investigated as environmentally friendly sono-photocatalytic system under LED visible light irradiation to efficiently mineralize tetracycline-based antibiotics. The effects of pH, Ca doping, light, ultrasound, and pH on the mineralization of tetracycline by Ca-doped ZnO nanopowders and on the chemical, sono-, photo- and sono-photostability of Ca-doped ZnO nanopowders were systematically investigated. The ZnO-based catalyst with 2 at. % of Ca dopant exhibited the best sono-photocatalytic performance in mineralizing tetracyclines under visible LED light and ultrasound irradiation (i.e., ≥ 99% mineralization in 90 min), with excellent reusability and minimal sono-photocorrosion (i.e., ≤ 1% of catalyst dissolution in 180 min), which were even greater in the absence of organic pollutants and in the pH range of most natural waters. For Ca-doped ZnO nanopowders, the role of the generated reactive oxygen species under light and ultrasound stimulation and the mechanism of the mineralization of tetracycline were analyzed. In conclusion, the sono-photocatalytic mineralization of antibiotics synergizing visible LED light and weak ultrasound irradiation in the presence of Ca-doped ZnO nanopowders presents an outstanding start to developing highly efficient, long-term, eco-friendly catalysts for efficiently treating emerging organic pollutants.

The ZnO-based visible-LED photocatalytic degradation and mineralization of two typical cyanotoxins, microcystin-LR (MC-LR), and anatoxin-A were examined. Al-doped ZnO nanoparticle photocatalysts, in Al:Zn ratios between 0 and 5 at.%, were prepared via sol-gel method and exhaustively characterized by X-ray diffraction, transmission electron microscopy, UV-vis diffuse reflectance spectroscopy, photoluminescence spectroscopy, and nitrogen adsorption-desorption isotherms. With both cyanotoxins, increasing the Al content enhances the degradation kinetics, hence the use of nanoparticles with 5 at.% Al content (A5ZO). The dosage affected both cyanotoxins similarly, and the photocatalytic degradation kinetics improved with photocatalyst concentrations between 0.5 and 1.0 g L&minus, 1. Nevertheless, the pH study revealed that the chemical state of a species decisively facilitates the mutual interaction of cyanotoxin and photocatalysts. A5ZO nanoparticles achieved better outcomes than other photocatalysts to date, and after 180 min, the mineralization of anatoxin-A was virtually complete in weak alkaline medium, whereas only 45% of MC-LR was in neutral conditions. Moreover, photocatalyst reusability is clear for anatoxin-A, but it is adversely affected for MC-LR.

Time resolved Raman spectroelectrochemistry is a powerful technique to prepare useful Surface Enhanced Raman Scattering (SERS) substrates suitable for quantitative analysis. Moreover, following the evolution of the Raman signal with the applied potential the selection of the best conditions for the analysis is quite simple. In this work, gold SERS substrates are prepared on screen-printed electrodes for the determination of nicotinamide, vitamin B3, in a multivitamin complex. The formation of the substrate has been monitored using UV/Vis absorption spectroelectrochemistry and scanning electron microscopy, which confirmed the generation of gold nanoparticles on the electrode surface. This new method has demonstrated to be suitable for the direct quantification of simple test samples using small sample volumes (50 μL). However, it failed when a complex sample, containing several interfering species, was analysed. A high interference on the preparation of the SERS substrate is observed during the analysis of a multivitamin complex. Despite that, nicotinamide was selectively determined in a multivitamin complex using the method of the standard addition, obtaining remarkable figures of merit (R2 = 0.99, %RSD < 9%)., Ministerio de Economía, y Competitividad (Grant CTQ2017-83935-R-AEI/FEDERUE), Junta de Castilla y León (Grant BU297P18) and Ministerio de Ciencia, Innovación y Universidades (Grant RED2018-102412-T). J.V.P-R. thanks Junta de Castilla y León for his postdoctoral fellowship (Grant BU033-U16)

Electrochemical Surface Oxidation Enhanced Raman Scattering (EC-SOERS) is an interesting and promising phenomenon capable of amplifying the Raman signal in a similar way to Surface Enhanced Raman Scattering (SERS), but EC-SOERS takes place during the oxidation of a silver substrate. This phenomenon was originally described for specific electrolytic conditions in which a small amount of chloride in acidic medium was mandatory to obtain a substantial enhancement. Herein, we demonstrate that EC-SOERS can be also observed in presence of KBr, showing a potential-dependent behavior. Moreover, in this work a novel approach to reach chemical selectivity during time resolved Raman spectroelectrochemistry (TR-Raman-SEC) experiments is proposed. This new approach is based on the effect of the electrolytic medium on the structures that are formed on the electrode surface. SEM studies were carried out to study the origin of this selectivity. Although SEM images reveal clear differences between the structures of silver halides formed on the electrode surface during the oxidation of the substrate, the absence of EC-SOERS effect at open circuit potential hinders the identification of the actual structures responsible for the phenomenon., Ministerio de Economía y Competitividad (Grants CTQ2017-83935-R-AEI/FEDERUE), Junta de Castilla y León (BU297P18) and Ministerio de Ciencia, Innovación y Universidades (RED2018-102412-T)

Recognition of the spatial variation in tree species composition is a necessary precondition for wise management and conservation of forests. In the Peruvian Amazonia, this goal is not yet achieved mostly because adequate species inventory data has been lacking. The recently started Peruvian national forest inventory (INFFS) is expected to change the situation. Here, we analyzed genus-level variation, summarized through non-metric multidimensional scaling (NMDS), in a set of 157 INFFS inventory plots in lowland to low mountain rain forests (&lt, 2000 m above sea level) using Landsat satellite imagery and climatic, edaphic, and elevation data as predictor variables. Genus-level floristic patterns have earlier been found to be indicative of species-level patterns. In correlation tests, the floristic variation of tree genera was most strongly related to Landsat variables and secondly to climatic variables. We used random forest regression, under varying criteria of feature selection and cross-validation, to predict the floristic composition on the basis of Landsat and environmental data. The best model explained &gt, 60% of the variation along NMDS axes 1 and 2 and 40% of the variation along NMDS axis 3. We used this model to predict the three NMDS dimensions at a 450-m resolution over all of the Peruvian Amazonia and classified the pixels into 10 floristic classes using k-means classification. An indicator analysis identified statistically significant indicator genera for 8 out of the 10 classes. The results are congruent with earlier studies, suggesting that the approach is robust and can be applied to other tropical regions, which is useful for reducing research gaps and for identifying suitable areas for conservation.

The development of new, efficient, chemoselective, and seemingly stable catalysts to rapidly convert 4-nitrophenol into 4-aminophenol, which is a particularly valuable chemical within multiple industries, is highly required. The use of non-toxic and non-corrosive chemicals for 4-aminophenol synthesis presents further challenges. We show a simple and scalable shape-controlled electrodeposition using a dual-template method for the synthesis of well-defined porous Au micropillar array electrodes to enhance electrocatalyst stability, efficiency, and durability during the electroreduction of 4-nitrophenol. Consequently, we avoid the use of toxic and aggressive chemical reducing agents and minimize the production of residues. Surface areas up to 55.2 m2 g−1 are achieved, which represent a substantial improvement over non-architectured Au film electrodes. Porous Au micropillars exhibit excellent yields (100 %), chemoselectivity (other byproducts are not detected), and a high kinetic constant of 2.5 × 10-2 min−1, which is impressively higher than those reported recently for Au thin films or Au-based electrocatalysts.

Microalgae can be easily integrated into an effective and scalable zero-carbon-emission circular process that exploits their CO2 fixation and wastewater remediation capabilities while simultaneously using their residues as an energy and biofuel source to power global sustainable development. Herein, the use of glycogen-rich Arthrospira platensis microalgae for efficient water decontamination, biofuel production, and CO2 fixation is explored. The circular process is initiated by efficient bioremediation of heavy metals (removal >99%) during microalgal growth, followed by bioethanol production, pellet production, and mineralization of persistent organic pollutants from wastewater, and is accompanied by CO2 fixation and/or oxygen production. Microalgal biomass generated during heavy metal bioremediation is used to produce bioethanol via simultaneous saccharification and fermentation (0.4 L per kg of dried microalgal biomass). The residual biomass obtained after bioethanol production is dried and compressed into pellets for its use as a fuel in biomass boilers (calorific power = 20.6 ± 0.2 MJ kg−1). The iron-rich ashes produced during pellet combustion are subsequently used as heterogeneous re-usable Fenton-like catalysts for the photo-Fenton degradation (mineralization >99%) of persistent organic pollutants. Finally, the low-activity ashes are incorporated into an ash-based medium for the efficient cultivation of microalgae. For each proposed step, product characterization and evaluation were conducted to optimize and enhance the process performance while minimizing negative effects on the environment.

The widespread use and negative environmental effects of antibiotics have made their removal from aqueous media essential in terms of wastewater treatment. Accordingly, a hybrid helical Cu@Cu2O@CuO–microalgae photocatalyst for antibiotic photodegradation was synthesized in this study by a simple, inexpensive, and scalable process based on electroless Cu deposition and soft thermal treatment. The hybrid photocatalyst was more competitive for the photocatalytic degradation of tetracycline, especially in terms of mineralization and energy consumption, than state-of-the-art photocatalysts. The excellent photocatalytic performance is attributable to the effective formation of onion-like Cu@Cu2O@CuO heterojunctions, which synergistically lower the electron–hole recombination rate, promote the utilization of light and photogeneration of charge carriers, and decrease the photocorrosion activity. All these effects result in the enhanced photocatalytic degradation and mineralization of tetracycline. The high photocatalytic performance of the Cu@Cu2O@CuO–microalgae hybrids under LED irradiation resulted in a significantly lower electrical energy per order—i.e., the electrical energy required to diminish the tetracycline concentration by one order of magnitude in a unit of volume—of 57 kW h m−3 order-1. Importantly, the Cu@Cu2O@CuO–microalgae hybrids can easily be recycled after reaching their effective lifetime to fabricate competitive microalgal pellets, then integrated into a circular process in an environment–energy nexus to minimize the generation of residues.

A hybrid magnetic-ZnO-based photocatalyst platform is designed for the efficient and simultaneous sunlight-driven photoremoval of cyanobacteria and mineralization of cyanotoxins (anatoxin-A). The photocatalyst killing ability was evaluated against two types of microalgae with different morphology and toxicity, Spirulina platensis paracas and Anabaena flos-aquae. The hybrid photocatalyst Ni@ZnO@ZnS-Spirulina was synthetized by means of a multistep process using Spirulina as biotemplate. The effects of reactor geometry, magnetic actuation, and concordant architecture on photokilling ability were tested. Moreover, the prepared photocatalysts were demonstrated to be effective for the anatoxin-A degradation under artificial sunlight. In the interest of reducing waste content and optimizing resources, photocatalyst recycling after their useful lifetime has ended is proposed through the fabrication of microalgal biofuel-pellets. This inexpensive circular process involves multi-functional algae-based photocatalysts applied to the simultaneous destruction of algae blooms and cyanotoxins and then recycled to close the circle through cultivating biotemplates., Applied Catalysis B: Environmental, 268, ISSN:1873-3883, ISSN:0926-3373

Water remediation and development of carbon‐neutral fuels are a priority for the evermore industrialized society. The answer to these challenges should be simple, sustainable, and inexpensive. Thus, biomimetic‐inspired circular and holistic processes combing water remediation and biofuel production can be an appealing concept to deal with these global issues. A simple circular approach using helical Spirulina platensis microalgae as biotemplates to synthesize Ni@ZnO@ZnS photocatalysts for efficient solar water decontamination and bioethanol production during the recycling process is presented. Under solar irradiation, the Ni@ZnO@ZnS‐Spirulina photocatalyst exhibits enhanced activity (mineralization efficiency >99%) with minimal photocorrosion and excellent reusability. At the end of its effective lifetime for water remediation, the microalgae skeleton (mainly glycogen and glucose) of the photocatalyst is recycled to directly produce bioethanol by simultaneous saccharification and fermentation process. An outstanding ethanol yield of 0.4 L kg−1, which is similar to the highest yield obtained from oxygenic photosynthetic microorganisms, is obtained. Thus, the entire process allows effective solar photocatalytic water remediation and bioethanol production at room temperature using simple and easily scalable procedures that simultaneously fixes carbon dioxide, thereby constituting a zero‐carbon‐emission circular process., The work leading to these results received funding from Metrohm foundation, from the 2017‐SGR‐292 project from the Generalitat de Catalunya, and the PCIN2016‐093 and TEC2017‐85059‐C3‐2‐R projects (co‐financed by the Fondo Europeo de Desarrollo Regional, FEDER) from the Spanish Ministerio de Economía y Competitividad (MINECO). The authors also acknowledge Espirulina Natural (Dra. Ester Falgàs) and Societé Industrielle Lesaffre, Division Leaf for the provision of the microalgae and Ethanol Red yeast, respectively. A.S. would like to acknowledge funding from the EMPAPOSTDOCS‐II program. The EMPAPOSTDOCS‐II programme has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Skłodowska‐Curie grant agreement number 754364. ICN2 is funded by the CERCA Programme/Generalitat de Catalunya. The ICN2 is supported by the Severo Ochoa Centres of Excellence programme, funded by the Spanish Research Agency (AEI, grant no. SEV‐2017‐0706).

The purpose of this systematic study was to investigate the effects of specific substrates and potential conditions applied while tailoring the morphology and chemical composition of nanostructured Co films. In particular, Co electrodeposition in sustainable choline chloride-urea deep eutectic solvent was assessed, using glassy carbon and two metals widely employed in electrocatalysis and biocompatible purposes, Pt and Au, as substrates for modification with Co. Various in situ electrochemical techniques were combined with a broad range of ex-situ characterization and chemical-composition techniques for a detailed analysis of the prepared Co films. Among the results, nanostructured Co films with high extended active surface areas and variable composition of oxo and hydroxyl species could be tuned by simply modulating the applied potential limits, and without using additives or surfactant agents. The study highlights the effectiveness of using deep eutectic solvent as suitable electrolyte for surface modification by controlled deposition of nanostructured Co films with further application in electrocatalysis.

Currently, there is massive generation of persistent organic pollutants, which are hazardous substances, owing to the exponential industrial growth and the associated waste production. Consequently, green and reliable strategies for decontaminating wastewater and generating value-added products are needed to realize the global demand of sustainability. In this study, an efficient sustainable circular process for water remediation with nearly zero residue production is developed using iron-rich cyanobacteria ashes. These cyanobacteria ashes are obtained from the combustion of Arthrospira platensis var lonar and are used as Fenton-like photocatalysts in different assisted photo-Fenton reactions (processes enhanced by light). The use of these iron-rich cyanobacteria ashes is particularly effective for the sono-enhanced photo-Fenton processes for water remediation (mineralization > 94.9%), with an outstanding reusability. At the end of the effective lifetime of the photocatalyst, the remaining ashes can be subsequently reused as a supplement during the growth of new cyanobacteria, thus closing the circular process. The proposed approach is a green and sustainable process integrating both carbon dioxide fixation and clean-water production aimed at attaining sustainable development.

The first steps of nickel electrodeposition in a deep eutectic solvent (DES) are analyzed in detail. Several substrates from glassy carbon to Pt(111) were investigated pointing out the surface sensitivity of the nucleation and growth mechanism. For that, cyclic voltammetry and chronoamperometry, in combination with scanning electron microscopy (SEM), were employed. X-ray diffraction (XRD) and atomic force microscopy (AFM) were used to more deeply analyze the Ni deposition on Pt substrates. In a 0.1 M NiCl2 + DES solution (at 70 °C), the nickel deposition on glassy carbon takes place within the potential limits of the electrode in the blank solution. Although, the electrochemical window of Pt|DES is considerably shorter than on glassy carbon|DES, it was still sufficient for the nickel deposition. On the Pt electrode, the negative potential limit was enlarged while the nickel deposit grew, likely because of the lower catalytic activity of the nickel toward the reduction of the DES. At lower overpotentials, different hydrogenated Ni structures were favored, most likely because of the DES co-reduction on the Pt substrate. Nanometric metallic nickel grains of rounded shape were obtained on any substrate, as evidenced by the FE-SEM. Passivation phenomena, related to the formation of Ni oxide and Ni hydroxylated species, were observed at high applied overpotentials. At low deposited charge, on Pt(111) the AFM measurements showed the formation of rounded nanometric particles of Ni, which rearranged and formed small triangular arrays at sufficiently low applied overpotential. This particle pattern was induced by the ⟨111⟩ orientation and related to surface sensitivity of the nickel deposition in DES. The present work provides deep insights into the Ni electrodeposition mechanism in the selected deep eutectic solvent. This work has been financially supported by the MCINN-FEDER (Spain) through the projects CTQ2016-76221-P and TEC2014-51940-C2-2R. P.S. acknowledges MECD for the award of an FPU grant.

Real-time process monitoring is still relatively scarce but is fundamental to provide in-situ information about different chemical and electrochemical processes. Particularly, electrochemical filtration has received growing attention in recent years due to the wide range of applications in which it can be successfully employed. Electrochemical removal is considered as an attractive methodology for the treatment of wastewater due to its efficiency in the removal of a huge number of contaminants. In this work, the development of a new device based on the use of UV–vis bare optical fibers in long optical pathway configuration allows us to monitor continuously the electrochemical degradation process during the filtration of different compounds. Spectroelectrochemistry additionally supplies quantitative information allowing us to calculate the efficiency of the electrochemical filtration process. The material selected to fabricate the electrochemical filter was single-walled carbon nanotubes that display not only high physical and chemical stability, but also high electrical conductivity. Therefore, the combination of electrochemical degradation methods, free-standing single-walled carbon nanotube filters and operando spectroelectrochemical techniques makes this outstanding device very interesting in the study of different molecules. As proof of concept, three different systems have been studied to validate the cell and demonstrate the good performance of the spectroelectrochemical device: o-tolidine (reference system), indigo carmine (organic dye), and 4-nitrophenol (hazardous pollutant)., Ministerio de Economía y Competitividad (CTQ2014-61914-EXP, CTQ2014-55583-R, TEC2017-85059-C3-2-R, CTQ2015-71955-REDT) and Junta de Castilla y León (BU033-U16)

This work proposes a pretreatment strategy of a flame-annealed Pt(111) single crystal ensuring surface ordering and avoiding water surface contamination for experiments in ionic liquid (IL) media. A room temperature ionic liquid (RTIL) and a deep eutectic solvent (DES) representative of two families of ionic liquids were selected as test electrolytes: The RTIL used was the 1-ethyl-2,3-dimethylimidazolium bis(trifluoromethyl)sulfonylimide ([Emmim][Tf2N]), and the DES was based on the eutectic mixture of choline chloride (ChCl) and urea (1ChCl:2urea molar ratio). The electrode was flame-annealed and, instead of the water quenching step, it was cooled down in CO atmosphere until the surface was fully covered by a protective carbon monoxide (CO) layer. Prior to experiments, the removal of CO from the surface was performed by electrochemical oxidation. The CO reactivity on Pt(111) was different depending on the IL nature. While CO is easily oxidized to CO2 in [Emmim][Tf2N], in DES, CO remains adsorbed on the substrate and restructures undergoing an order–disorder transition. For both liquids, the proposed method allows for obtaining neat blank cyclic voltammograms, demonstrating that the adsorption of CO is a useful tool to protect the high catalytic surfaces, such as Pt in contact with ILs. To illustrate the feasibility of the CO treatment in electrochemical work with ILs, the general trends for the modification of Pt(111) single crystal surface with metallic nickel nanostructures on both types of IL was investigated. Nickel electrodeposition on the Pt(111) substrate was explored in both [Emmim][Tf2N] and DES by using classical electrochemical techniques, such as cyclic voltammetry and chronoamperometry, while the deposits were characterized by FE-SEM, EDS, and XPS. This work has been financially supported by the MCINN-FEDER (Spain) through the projects: CTQ2016-76221-P and TEC2017-85059-C3-2R. P. Sebastian acknowledges MECD for the award of a FPU grant.

From the appearance of the ionic liquids (IL), the interest on these novel compounds has been in continuous increase as alternative solvent for many purposes. The incorporation of ILs has been gradually spreading in many routes related to several electrochemical processes in order to ascertain the feasibility of their use. In particular, one of the fields in which ILs have attracted more attention during the last years is metal electrodeposition. There has been an explosion in the number of ILs of different types applied to a variety of metal deposition processes. More recently, some fundamental electrochemical studies on the behavior of metal deposition have begun. ILs were initially proposed to overcome the important drawbacks associated with the deposition of some metals in aqueous media, especially for those with a reduction potential more negative than that of water reduction or for those that in aqueous media suffer undesired reactions. The fact that some of these metals were being incorporated in the electronic industry further motivated the study of electrodeposition processes using ILs. However, at present, this is not the only goal but it rather is to provide, for a wide spectrum of metals, singular structures using these green solvents with low environmental impact, thus replacing in some cases aqueous baths that contain hazardous additives. In addition, some nanostructured materials obtained in confined conditions in the aqueous medium have also been obtained using ILs because their structure in the interfacial region could act as soft templates.

We have established a facile and generalizable electrochemical synthesis of metallic mesoporous nanorods in the nanochannels of commercial polycarbonate membranes using microemulsions containing ionic liquids. Herein, we report the preparation of magnetic CoPt nanorods with various meso or nanopores distributions, depending on the microemulsion type (ionic liquid –in-water (IL/W), bicontinuous (β) or water-in-ionic liquid (W/IL)). The synthesized porous nanorods show a much enhanced electrocatalytic activity for methanol oxidation in comparison with compact Pt nanorods (up to 12 times) or Pt/C electrocatalyst (Pt nanoparticles or commercial black platinum). Therefore, the synthesized CoPt mesoporous nanorods could be excellent catalysts in direct methanol fuel cells (DMFC's), as they have high surface areas, large pore volumes and high corrosion stability, and they exhibit promising catalytic properties.

This is an in depth study in the knowledge of the nucleation and growth mechanism that governs copper electrodeposition in excess chloride media. In these conditions copper electro-reduction takes place via two well-separated steps, since the Cu(I) intermediate is stabilized through chloride complexation. The process was studied in two media, a deep eutectic solvent (DES) based on a mixture of urea and choline chloride, and in excess chloride aqueous solution, in order to also analyse solvent influence on the early stages of the deposition process. In both media, copper electrodeposition follows a nucleation and a diffusion controlled three-dimensional growth mechanism. In line with a previous work a double potentiostatic step signal was employed to record j–t transients associated to both nucleation and growth stages, and from them, the whole mechanistic analysis of the copper electrodeposition was performed. This analysis involved the calculation of the surface concentrations of Cu(II), free Cu(I) and complexed Cu(I) for any time and potential required and the application of Sharifker-Hills model, jm2tm products and rising part analysis including the calculated parameters, which are strengthened as valuable tools for complete copper electrodeposition analysis in these media.

Janus structures represent an overwhelming member of materials with adaptable chemical and physical properties. Development of new synthesis routes has allowed the fabrication of Janus architectures with specific characteristics depending on the final applications. In the case of the membranes, the improvement of wet routes has been limited to the capillary effect, in which the solution can gradually penetrate through the membrane, avoiding a double modification different at each face of the membrane. In this work, we propose a new electrochemical methodology to circumvent the capillary limitation and obtain a double electrochemical functionalization in only one step in a controlled way. This innovative methodology has been validated using a tridirectional spectroelectrochemistry setup. Moreover, the information provided by this optical arrangement should be especially useful for the study of the different processes (ion transfer, assisted ion transfer, and electron transfer) that can take place at liquid/liquid interfaces. Janus electrochemistry allows us to modify the two faces of a free-standing single-walled carbon nanotube electrode in a single experiment. As proof of concept, the free-standing films have been functionalized with two different conducting polymers, polyaniline and poly(3-hexylthiophene), in one electrochemical experiment. According to the obtained results, this new electrochemical methodology will open new gates for the design and functionalization of Janus materials., Ministerio de Economía y Competitividad (Grants CTQ2014-61914-EXP, CTQ2014-55583-R, TEC2014-51940-C2-2R, and CTQ2015-71955-REDT) and Junta de Castilla y León (Grant BU033-U16)

The electrodeposition of copper on a polycrystalline gold electrode and on Au(hkl) single crystals was investigated in a deep eutectic solvent (DES). The DES employed consisted of a mixture of choline chloride and urea (1:2). The Au(hkl)/DES interface was studied using cyclic voltammetry in the capacitive region. The blank voltammograms showed characteristic features, not previously reported, that demonstrate the surface sensitivity of this solvent. Copper electrodeposition was then studied and it was found that this takes place through the formation of an underpotential deposition (UPD) adlayer, demonstrating the surface sensitivity of this process. Voltammetric profiles showed similarities with those obtained in aqueous solutions containing chloride, suggesting that the copper UPD in this DES is strongly influenced by the presence of chloride. Financial support from MINECO through projects CTQ2016-76221-P (AEI/FEDER, UE) and TEC2014-51940-C2-2-R (AEI/FEDER, UE) are greatly acknowledged. P. Sebastian also acknowledges MECD for FPU grant.