The electrochemical reduction of CO2 to ethanol represents a sustainable alternative to recycle CO2 into a value-added product, yet achieving high selectivity and efficiency remains a challenge. This work explores Cu-based catalysts supported on SiO2 and ZrO2, with and without ZnO doping, for ethanol production in a continuous flow-cell system. Gas diffusion electrodes are fabricated using commercial catalysts with varying Cu loadings (5–10%) and ZnO contents (2–3.5%). Comprehensive characterization by XPS confirms the presence of Cu2+ and Zn2+ species, while SEM reveals that ZnO incorporation improves surface uniformity and aggregate distribution compared to undoped samples. Electrochemical tests demonstrate that 10% Cu on SiO2 achieves a Faradaic efficiency of 96% for ethanol at −3 mA cm−2, outperforming both doped catalysts and previously reported materials. However, efficiency declines at higher current densities, indicating a trade-off between selectivity and productivity. ZnO doping enhances C2+ product formation but does not surpass the undoped catalyst in ethanol selectivity. These results underline the importance of catalyst composition, support interactions, and operating conditions, and point to further optimization of electrode architecture and cell configuration to sustain high ethanol yields under industrially relevant conditions.

The large-scale microwave plasma synthesis of graphene and nitrogen-doped graphene with tailored structural properties, crucial for their successful usage applications, has been demonstrated. The developed atmospheric pressure plasma method offers several advantages, including the continuous production of high-quality, free-standing graphene without the use of chemicals, solvents, catalysts, or additional heating. This non-toxic process eliminates the need for vacuum systems while achieving high temperatures. The method enables the precise control over graphene’s properties, such as the layer number, defects, sheet size, uniformity, and functionality, as well as the doping type and configuration, by adjusting the plasma parameters. Protocols for the synthesis of specific nanostructures with a controlled structural quality, production rate, and chemical composition have been established using methane and methylamine as precursors. The comprehensive physicochemical characterization of the graphene and nitrogen-doped graphene was carried out using scanning electron microscopy, high-resolution transmission electron microscopy, Raman spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy.

Laboratory experiments extend our possibility to understand the behavior of organic molecules under extraterrestrial conditions. In the scope of such simulation experiments, organic molecules are often prepared as thin films, embedded in ice matrices, or adsorbed onto mineral surfaces. Albeit a single-species approach often adequately mimics the conditions to be studied, there are scenarios where the interactions between different organic molecules should be considered. In this work, we investigate the interaction of the two simplest α-amino acids, glycine and alanine, while codeposited as homogeneous nanolayers. Our results demonstrate that their interaction leads to deposition patterns, infrared signatures, and electronic properties that cannot be predicted by studying each molecular species in isolation. We conclude that organic interactions influence the photochemistry and spectroscopic signatures of biomolecules potentially present in planetary environments of interest such as Titan's surface.

MnCo2O4 and CoMn2O4 were successfully synthesized on a stainless-steel substrate using the hydrothermal method. The structural and morphological characteristics of the spinel samples were investigated using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The electronic and vibrational properties were studied through X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). Electrochemical properties were also evaluated using a three-electrode system associated with an electrochemical workstation. The studies revealed that the inversion of Mn and Co cation distribution between the spinel structure sites not only modifies the crystal structure and morphology but also alters specific functional properties. MnCo2O4 crystallized in a cubic spinel phase, exhibiting spherical particles, pronounced microstrain, and stronger metal–oxygen bonding. In contrast, CoMn2O4 adopted a tetragonal spinel structure with rod-like crystallites, lower microstrain, and more flexible bonding environments. Electrochemical impedance spectroscopy further revealed distinct charge-transfer dynamics, indicating differences in surface redox activity. This comparative analysis elucidates how cation site occupancy governs the performance of the synthesized spinel oxides and underscores their potential as efficient catalysts or catalyst supports for redox and energy-related applications.

This study investigated the effects of silver doping, natural ageing, and thermal-induced oxidation on the surface chemistry, morphology, and thermal performance of copper thin films. Ag is used as a doping element in Cu because, in bulk materials it usually refines microstructures, leading to increased hardness and mechanical strength through mechanisms such as solid solution strengthening and twinning. In this work was also used due to its oxidation resistance. Thin films of pure and silver-doped copper (Cu_2Ag and Cu_4Ag) were deposited by RF magnetron sputtering and characterized as-deposited, naturally aged, at room temperature and humidity for one year, and thermally treated at 200 °C, in air. The characterization included X-ray photoelectron spectroscopy (XPS), Atomic Force microscopy (AFM), and thermal analysis, specifically thermal conductivity (λ), thermal diffusivity (α), and thermal capacity (ρ.Cp). Surface XPS analysis revealed changes in copper and silver oxidation states after natural aging and annealing. AFM revelead that the incorporation of silver and heat treatment altered the surface roughness and morphology. Thermal analysis found that for lower silver concentrations, the thermal conductivity increased, but aging and annealing had varying effects depending on the silver content. The Cu_4Ag film showed the best thermal stability after natural ageing. Overall, the results suggest that carefully controlled silver doping can enhance the thermal stability of copper thin films for applications where aging is a concern, such as microelectronics.

Electroconductive polymers (ECP) are critical for the design of soft electronic and bioelectronic devices. Polyaniline:camphorsulfonic acid (PANI:CSA) is an example of a biocompatible and affordable ECP, whose electroconductivity is highly dependent on chain organization/conformation. PANI:CSA aggregation ordering is overlooked in most works, but it can greatly impact the performance of PANI:CSA-based devices and limit their applicability. A simple and cheap method to avoid random coil aggregation of PANI:CSA is to select solvents with pseudo-doping properties. This work presents a novel alternative solvent system, based on trifluoroethanol (TFE) and hexafluoropropanol (HFP) mixtures, capable of being removed without hampering the structural and electrical properties of PANI:CSA. For the first time, we present a systematic study that compares the performance of solvent systems containing different amounts of TFE and HFP, which, unlike m-cresol, the goldenstandard of pseudo-doping, are easy to remove without compromising the ECP's electroconductivity and biocompatibility. We also evaluate the influence of the processing method, drop-casting vs spin-coating, on the structural and electrical properties of the obtained samples. Samples obtained by spin-coating show a more consistent improvement in electroconductivity (sigma(TFE) = 61 S cm-1, sigma(TFE:HFP (50:50 vol)) = 70 S cm-1) and more intense near-infrared (NIR) absorption bands. Atomic force microscopy (AFM), Raman spectroscopy and Xray photoelectron spectroscopy (XPS) indicate that samples processed with HFP and m-cresol have higher benzenoid content, lower random coil aggregation and more efficient CSA doping. The solvent system comprised of equal parts of TFE and HFP was found to simultaneously enhance the electrical properties and structural ordering of PANI:CSA. We believe our results are critical for the fabrication of PANI-based next generation bioelectronic devices.

Hydrates are ice-like crystalline structures of hydrogen-bonded water molecules that trap a guest molecule. Hydrates have several applications, including carbon sequestration, gas separation, desalination, etc. A classical major challenge associated with artificial hydrate formation is the very long induction time to nucleate hydrates. This has spurred the development of multiple chemical, mechanical, and electrical strategies to promote nucleation. Presently, we discover that magnesium can significantly promote the nucleation of tetrahydrofuran (THF) hydrates. While magnesium has been recently shown (by our group) to promote the formation of carbon dioxide hydrates (gas-liquid system), this study discovers that the benefits of magnesium extend to liquid-liquid hydrate systems as well. Experiments show that magnesium reduces the induction time for THF hydrate nucleation with deionized (DI) water and saltwater by six and eight times, respectively. Magnesium-induced nucleation rate enhancements for hydrate formation with DI water and saltwater were 12 and 99 times, respectively. Importantly, we demonstrate near-instantaneous nucleation when magnesium is introduced after the hydrate-forming system reaches suitable thermodynamic conditions. We conduct statistically significant measurements of nucleation and XPS analysis to identify the underlying mechanisms responsible for nucleation. We discuss multiple phenomena at play, including chemical and mechanistic promotion pathways. The formation of hydrogen bubbles and the presence of magnesium ions in solution are seen as important to magnesium-based nucleation promotion. Importantly, very low amounts of Mg are consumed in this process unlike in traditional chemical promotion techniques. Overall, our discovery can enable on-demand nucleation of liquid-liquid hydrate systems, which is critical to the development of several applications.

The deoxygenation of sulfoxides is a rather important reaction from both synthetic and biological points of view, due to the potential of sulfides as intermediates in a variety of processes. Homogenous Mo-based catalysts successfully perform the reduction of diphenyl sulfoxide to diphenyl sulfide with high yields but present the well-known limitations regarding recovery and recycling. Thus, in the present work, two new supported catalysts were prepared through the immobilization of molybdenum precursor species (dichlorodioxodi(aquo)molybde-num(VI) and sodium molybdate), onto a sisal-derived acid-char (S13.5), obtained from rope industry wastes by acid-mediated carbonization. The heterogeneous Mo-based materials were characterized by IR spectroscopy, elemental analysis, ICP, solid state NMR, oS, and SEM, and were evaluated as catalysts for the reduction of sulfoxides to sulfides in the presence of phenylsilane as reducing agent under different reaction conditions. The influence of various experimental parameters, including reducing agent type and amount, solvent type, and acid promoter were investigated. Catalytic studies revealed that both catalysts deoxygenate sulfoxides at 120 degrees C in toluene solution with high yields (up to 97%). The MoO2Cl2 derived catalyst shown to be highly efficient in the reduction of diaryl, alkylaryl, dibenzyl, and dialkyl sulfoxides to the corresponding sulfoxides using phenylsilane as reductant and no need of acid promoter.

Many interesting materials in a broad range of applications have in their composition the coexistence of zinc and iron. Their characterization by XPS should identify and quantify both elements. The most intense regions for these elements Zn 2p and Fe 2p are, therefore, used to accomplish that purpose. By using sphalerite as an example of a material where Zn and Fe may coexist and using XPS with two different X radiation sources to study them, it is demonstrated that the Fe 2p region, when the iron is the minor component, may be seriously affected by the Auger Zn L3M1M23 structure. The sphalerite (Zn1−xFexS) here studied has x ≈ 0 and is a good example to show how an XPS spectrum obtained with the X-ray Al Kα, the most used radiation in monochromatic equipment, leads to a wrong assignment of the structures existing in the binding energy region of Fe 2p. The simultaneous use of Mg Kα radiation showed that the Fe 2p is below the XPS detection in this specific sample of sphalerite. Its attested absence reveals that the structure detected, when using Al Kα in the “Fe 2p” region, is assigned to a zinc Auger multiple peak and not to the expected 2p photoelectron doublet peak of iron.

The photo-electrochemical properties of pure SnO2 and Sb-doped SnO2 grown on Si substrate (Sb(%)/SnO2/Si) thin films synthesized by the Atmospheric Pressure Chemical Vapor Deposition (APCVD) were studied. The nature of the substrate and its chemical composition were assessed. SnO2 and Sb(%)/SnO2/Si films crystallize in a tetragonal rutile-structure and the Sb-doping does not affect the growth direction of the diffracted peaks but increases the crystallites size. The lower Sb/Sn ratio (similar to 0.2) revealed a better homogeneity of SnO2 onto Silicon than the glass substrate. Indeed, the AFM images showed that Si gives a smoother Sb/SnO2 film. The electrochemical measurements were studied with the variation of Sb(%)/SnO2/Si. The Capacitance-Potential (C-2 - E) characteristics confirmed the n-type nature induced by the compensation mechanism Sb5+/Sn4+, the flat band potentials of -0.83 and -0.85 V for SnO2/Si and Sb(0.85 %)/SnO2/Si respectively were obtained and both values are cathodic enough to reduce Cr(VI). The variation of the impedance with the frequency and the effect of the substrate on the transport properties showed that the grain boundaries dominate the conduction mechanism, influenced by the microstructures of the films (crystallography and texture). Sb(%)/SnO2/Si/Cr(VI) solution provided variable electrochemical properties, and an appreciable difference in the light absorbance confirmed the chromate reduction (lambda(max) = 350 nm, 16 ppm) to less hazardous form Cr3+; a conversion of 80 % was obtained under solar light.

In this study, we report the facile preparation of nanostructured Ag/Ag2S chemically immobilized on cotton fabric for solar and visible-light disinfection of drinking water. The hybrid photocatalyst textiles were obtained via a hydrothermal treatment of cotton fabric in the presence of previously prepared Ag2S or by in-situ immobilizing Ag followed by a reaction with sodium sulfide. Insights on the chemical, structural, morphological, optical, and luminescence properties of the appended nanostructured Ag/Ag2S were given using a large battery of characterization methods, including X-ray diffraction (XRD), Raman, ground state diffuse reflectance absorption (GSDR), time-resolved laser-induced luminescence (LIL), X-ray Photoelectron Spectroscopy (XPS) and Scanning Electron Microscopy (SEM) imaging. Their water disinfection aptitude, in water severely contaminated with E. coli, Salmonella and S. aureus (similar to 10(7) CFU/mL), was investigated under solar illumination as well as under a LED lamp, in batch and dynamic conditions. Deactivation of >90 % of bacteria was achieved after 15 min of illumination, and complete bacteria removal was ensured after 1 h of exposure, making the Cot-Ag2S a promising material for solar and visible-driven water disinfection purposes. The system was tested also under continuous feeding conditions using two different configurations of a homemade photoreactor, with varied water residence times. Considering the increasing threat of microbial contamination in drinking water supplies in developing rural areas, the present textile photocatalyst would afford an unconventional and innovative strategy for solar disinfection of drinking water that is low-cost and simple to implement with minimal infrastructures.

Self-standing vertically oriented carbon nanostructures (VCNs) were synthesized using a large-scale microwave plasma under low-pressure conditions, employing methane as a carbon precursor. The influence of plasma operational and substrate conditions on nanostructure growth and morphology were systematically studied. Furthermore, post-synthesis N-doping of VCNs with nitrogen content of 2.4 at% N was achieved using an Ar-N2 microwave plasma. Plasma-enabled direct deposition of VCNs, both doped and un-doped, onto nickel foils has been accomplished. The assessment of the developed nanostructures as electrodes in high-frequency AC filtering capacitors, has demonstrated an overall capacitance of approximately 480 mu F at 100 Hz, with a cut-off frequency of 4 kHz for a phase angle of - 45 degrees. The excellent electrochemical performance can be attributed to the appropriate structural and morphological properties peculiar for the directly deposited on nickel foil VCNs providing binder-free electrode fabrication, thus enhancing the electrode's conductivity and charge transfer kinetics. This plasma-enabled approach for electrode design on a large scale, coupled with excellent filtering performance, paves the way for many applications in high-frequency scenarios, offering an environmentally friendly alternative to conventional electrolytic capacitors.

Many interesting materials in a broad range of applications have in their composition the coexistence of zinc and iron. Their characterization by XPS should identify and quantify both elements. The most intense regions for these elements Zn 2p and Fe 2p are, therefore, used to accomplish that purpose. Using sphalerite as an example of a material where Zn and Fe may coexist and using XPS with two different X radiation sources to study them, it is demonstrated that Fe 2p region, when the iron is the minor component, may be seriously affected by the Auger Zn L3M1M23 structure. The sphalerite (Zn1-xFexS) here studied has x0 and is a good example to show how an XPS spectrum obtained with the X-ray Al Kα, the most used radiation in monochromatic equipments, leads to a wrong assignment of the structures existing in the binding energy region of Fe 2p. The simultaneous use of Mg Kα radiation showed that the Fe 2p is below the XPS detection in this specific sample of sphalerite. Its attested absence reveals that the structure detected, when using Al Kα in “Fe 2p” region, is assigned to a zinc Auger multiple peak and not to the expected 2p photoelectron doublet peak of iron.

CuMn2O4 (CMO) thin films are produced using a simple hydrothermal method. The influence of reaction duration on the electrodes’ electrochemical performance is investigated. XRD data shows improved crystal structure after 24-h reaction time, with a crystallite size of 12.17 nm. Distinct vibrational peaks associated with Cu–O and Mn–O are observed in the ATR-FTIR spectra, corroborating the spinel formation after 24 h. XPS analysis shows a compositional shift over time, starting with copper hydroxide at 12 h, evolving into a mix of copper and manganese oxides, hydroxides, and oxyhydroxides by 18 h, and achieving the desired spinel composition by 24 h. Microscopic analysis reveals CMO is arranged as small sheet structures, with 4.95 ± 2.92 µm in length after 24-h reaction. The CMO24h electrode displays a maximum specific capacitance of 1187.50 Fg−1 at a scan rate of 1 mVs−1 in 1 M Na2SO4 electrolyte. The electrochemical performance of the synthesized CMO electrodes reveals a high potential for energy storage applications.

Dental and orthopedic implants have become routine medical technologies for tooth replacement and bone fixation. Despite significant progress in implantology, achieving sufficient osseointegration remains a challenge, often leading to implant failure over the long term. Nanotechnology offers the potential to mimic the natural patterns of living tissues, providing a promising platform for tissue engineering and implant surface design. Among the various methods for developing nanostructures, High-Regular Laser-Induced Periodic Surface Structures (HR-LIPSS) techniques stand out for their ability to fabricate highly ordered nanostructures with excellent long-range repeatability and production efficiency. In this study, we utilized an innovative technical approach to generate traditional laser-induced superficial LIPSS nanostructures, followed by detailed surface analysis using classical microscopy and physicochemical methods. Our findings demonstrate for the first time that nanostructured LIPSS surfaces can significantly enhance cell adhesion and proliferation while providing an optimal environment for cell metabolism. Given the high reproducibility, low cost, and potential of HR-LIPSS techniques to support cell growth and differentiation, this novel technology has the potential to impact both the industrial development of new implants and clinical outcomes after implantation.

An unprecedented method has been developed to obtain heterometallic-organophosphine frameworks (HMOPFs) through a solvent-free, three-component mechanochemical process. In a ball mill, mixing copper (I) bromide with zinc (II), nickel (II) or copper (II) acetates, in the presence of (PTA-CH2-C6H4-p-COOH) Br (PTA is 1,3,5-triaza-7-phosphaadamantane) as an organic linker, has produced the corresponding HMOPFs based on Cu+-Zn2+, Cu+-Ni2+ and Cu+-Cu2+, respectively. The pyrolysis of HMOPFs resulted in bimetallic nanoparticles of transition metal phosphide and phosphate embedded in multi-P,N,Br-codoped carbon matrices (Cu-M@C). Due to the utilization of an aminophosphine organic linker, this HMOPFs-derived approach typifies an eco-friendly synthesis of carbon confined transition metal phosphides or phosphates. It avoids the common conventional methods that involves phosphorylation using large amounts of additional P sources, which leads to an intensive release of the flammable and poisonous phosphine gas. Also, the presence of Br at the organic linker eliminates the need for using bromine vapours to obtain halogen-doped carbon matrices. The Cu-M@C nanocomposites were tested as negative electrode materials for asymmetric supercapacitors. Electrochemical tests included cyclic voltammetry and galvanostatic charge-discharge experiments, which revealed the Cu-Zn@C electrode with a higher potential window as compared to Cu-Ni@C and Cu-Cu@C electrodes, achieving a rate performance of 60 % and high coulombic efficiency. An unprecedented solvent-free, mechanochemical method yields heterometallic organophosphine frameworks, which were pyrolyzed to obtain multi-P,N,Br-codoped carbon-confined binary transition metal phosphide and phosphate nanocomposites. The presented new approach offers an eco-friendly alternative to prepare electrode materials without the emission of hazardous phosphine gas and bromine vapours. The resulting materials were tested as electrodes for asymmetric supercapacitors and showed promising performance.image

Taking advantage of the high-energy-density microwave plasma environment as a unique 3D space for the self-assembly of free-standing nanostructures, a novel multifunctional platform for the continuous production of graphene and derivatives at the gram scale was developed. The platform is supported by a prototype plasma machine capable of performing a wide variety of industrially applicable processes within a single assembly environment. Free-standing graphene and nitrogen doped graphene, i.e., N-graphene nanosheets, and hybrid nanocomposites are assembled in a one-step process in seconds under atmospheric pressure conditions without the need of post-treatment. A single custom-designed machine enables the synthesis of an extensive array of hybrid nanomaterials featuring metal nanoparticles anchored in graphene. The method enables the conversion of a wide range of low-cost feedstock (e.g., ethanol, acetonitrile, etc.) into graphene and derivatives at a rate up to 30 mg/min. The resulting N-graphene sheets exhibit high quality, as evidenced by the highest reported presence of single atomic layers (45%), high ratio of 2D/G peak intensities in Raman spectra and N/O atomic ratio greater than one. The use of the obtained N-graphene in low secondary electron emission applications and in inkjet printing are explored. The presented plasma machine embodies significant potential to increase the effectiveness of plasma-driven process regarding productivity, costs and turnaround time.

Continuous advancements in understanding and controlling surface functionalisation and properties empower materials scientists to design materials with tailored characteristics, improved performance, and enhanced functionality, thereby expanding scientific knowledge and technological progress. This research paper presents the synthesis of two new metal-organic material-based films using the cathodic electrodeposition method. In contrast with the anodic deposition method, the cathodic deposition method offers the advantage of using non-metal electrode substrates and various metal ions, a unique aspect not yet fully explored. The study investigates the effects of linker length using 2,5-dihydroxyterephthalic acid (DOBDC) and 3,3'-dihydroxybiphenyl-4,4'-dicarboxylic acid (BPP) as organic linkers and iron(III) as the metal node for the structures. The films' electrochemical behaviour, characterisation through techniques like infrared spectroscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, X-Ray powder diffraction and grazing-Incidence small-angle X-ray scattering and particle-induced X-ray emission, as well as results from cyclic voltammetry studies, are discussed. The films were found to be nearly amorphous with specific grain sizes, revealing heterogeneity in composition and thickness. The unique synthesis method and comprehensive characterisation offer insights into the potential of electrosynthesis for designing functional materials and encourage further exploration of various synthesis conditions and metal ions.

Two samples of spent tire rubber (rubber A and rubber B) were submitted to thermochemical conversion by pyrolysis process. A450, B450 and A900, B900 chars were obtained from rubber A and rubber B at 450 degrees C and 900 degrees C, respectively. The chars were then applied as recovery agents of Nd3+ and Dy3+ from aqueous solutions in mono and bicomponent solutions, and their performance was benchmarked with a commercial activated carbon. The chars obtained at 900 degrees C were the most efficient adsorbents for both elements with uptake capacities around 30 mg g-1. The chars obtained at 450 degrees C presented uptake capacities similar to the commercial carbon (approximate to 11 mg g-1). A900 and B900 chars presented a higher availability of Zn ions that favored the ion exchange mechanism. It was found that Nd3+ and Dy3+ were adsorbed as oxides after Zn was released from silicate structures (Zn2SiO4). A900 char was further selected to be tested with Nd/Dy binary mixtures and it was found a trend to adsorb a slightly higher amount of Dy3+ due to its smaller ionic radius. The uptake capacity in bicomponent solutions was generally higher than for single component solutions due to the higher driving force triggered by the higher concentration gradient.