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The dependency of CO 2 reduction rate in acetonitrile-Bu 4 NClO 4 solution on cathodes, which were modified by laser induction of a copper surface, was studied. The topography of laser-induced periodic surface structures (LIPSS) → grooves → spikes was successively formed by a certain number of pulses. It was proved that for a higher number of laser pulses, the surface area of the copper cathode increases and preferred platy orientation of the copper surface on [022] crystallografic direction and larger fluence values increase. At the same time, the content of copper (I) oxide on the surface of the copper cathode increases. Also, the tendency to larger fluency values is observed. It promotes the increase of cathodic current density for CO 2 reduction, which reaches values of 14 mA cm -2 for samples with spikes surface structures at E = − 3.0 V upon a stable process.

Graphene oxide and reduced graphene oxide (RGO) are carbon bidimensional nanomaterials largely exploited in biomedicine. Their unique interactions with eukaryotic and prokaryotic cells are used to obtain precise intracellular delivery, to create device coatings, and to design theranostic materials for both therapeutic and imaging applications, mainly in the cancer research field. It is known, however, that the hydrophobic behavior of RGO limits its stability in biological media. Here, the employment of sodium ascorbate (NaA) as a reducing agent for the preparation of RGO to provide a nanomaterial with remarkable suitability for applications in cell culture media is proposed. It is demonstrated via a combined experimental and theoretical approach that NaA is able to yield a peculiar RGO derivative, exerting a twofold effect, that is, C sp2 network restoration upon epoxide reduction and RGO edge functionalization via H‐bonding, lending RGO a so far unexampled dispersibility in aqueous‐based media. The kinetic stability of the bidimensional layers of RGO obtained from NaA is demonstrated together with its superior biocompatibility for drug delivery, unlocking outstanding potentialities for biological applications. The use of sodium ascorbate as a green reducing agent for graphene oxide unlocks unprecedented stability of reduced graphene oxide in aqueous suspensions. This is due to the twofold activity of sodium ascorbate: restoration of the C sp2 basal network and edge‐functionalization with hydrophilic moieties. This is particularly advantageous for biological applications, toward better dispersion, cell entry, and lower cytotoxicity.

The present paper investigated the synthesis of peptide-based hydrogel composites containing photo-generated silver nanoparticles (AgNPs) obtained in the presence and absence of honey as tensile strength enhancer and hydrogel stabilizer. Fmoc-Phe and diphenylalanine (Phe2) were used as starting reagents for the hydrogelator synthesis via an enzymatic method. In particular, we developed an in situ one-pot approach for preparing AgNPs inside peptide hydrogels using a photochemical synthesis, without any toxic reducing agents, with reaction yields up to 30%. The structure and morphology of the nanohybrids were characterized with different techniques such as FESEM, UV-Vis, DLS, SAXS and XPS. Moreover, the antibacterial activity of these hybrid biomaterials was investigated on a laboratory strain and on a clinical isolate of Staphylococcus aureus. Results demonstrated that honey increased both swelling ability and also mechanical stability of the hydrogel. Finally, a higher antibacterial effect of AgNPs in the hybrid was observed in the presence of honey. In particular, AgNPs/hgel and AgNPs/hgel-honey showed an enhanced antibacterial activity (3.12 mg/L) compared to the free form of AgNPs, alone or in combination with honey (6.25 mg/L) for both S. aureus strains.

In this study, we present the synthesis of a novel peptide-based magnetogel obtained through the encapsulation of γ-Fe2O3-polyacrylic acid (PAA) nanoparticles (γ-Fe2O3NPs) into a hydrogel matrix, used for enhancing the ability of the hydrogel to remove Cr(III), Co(II), and Ni(II) pollutants from water. Fmoc-Phe (Fluorenylmethoxycarbonyl-Phenylalanine) and diphenylalanine (Phe2) were used as starting reagents for the hydrogelator (Fmoc-Phe3) synthesis via an enzymatic method. The PAA-coated magnetic nanoparticles were synthesized in a separate step, using the co-precipitation method, and encapsulated into the peptide-based hydrogel. The resulting organic/inorganic hybrid system (γ-Fe2O3NPs-peptide) was characterized with different techniques, including FT-IR, Raman, UV-Vis, DLS, ζ-potential, XPS, FESEM-EDS, swelling ability tests, and rheology. Regarding the application in heavy metals removal from aqueous solutions, the behavior of the obtained magnetogel was compared to its precursors and the effect of the magnetic field was assessed. Four different systems were studied for the separation of heavy metal ions from aqueous solutions, including (1) γ-Fe2O3NPs stabilized with PAA, (γ-Fe2O3NPs); (2) Fmoc-Phe3 hydrogel (HG); (3) γ-Fe2O3NPs embedded in peptide magnetogel (γ-Fe2O3NPs@HG); and (4) γ-Fe2O3NPs@HG in the presence of an external magnetic field. To quantify the removal efficiency of these four model systems, the UV-Vis technique was employed as a fast, cheap, and versatile method. The results demonstrate that both Fmoc-Phe3 hydrogel and γ-Fe2O3NPs peptide magnetogel can efficiently remove all the tested pollutants from water. Interestingly, due to the presence of magnetic γ-Fe2O3NPs inside the hydrogel, the removal efficiency can be enhanced by applying an external magnetic field. The proposed magnetogel represents a smart multifunctional nanosystem with improved absorption efficiency and synergic effect upon applying an external magnetic field. These results are promising for potential environmental applications of γ-Fe2O3NPs-peptide magnetogels to the removal of pollutants from aqueous media.

This study explores the potential of MAX phase/oxide nanocomposites as negative electrodes for lithium‐ion batteries. The main objective is to enhance the stability and performance of tin oxide‐based electrodes by reducing volume changes upon cycling. The approach involves the synthesis of a Sn‐containing MAX phase (Ti3Al0.3Sn0.7C2) followed by oxidation at different temperatures (600, 700, and 850 °C). Comprehensive characterization reveals that partial oxidation produces nanocomposites containing titanium and tin oxide nanoparticles with different compositions depending on the annealing temperature. The residual presence of the MAX phase contributes to the stability of the electrode, buffering volume changes during cycling. The sample oxidized at 700 °C exhibits the best trade‐off between specific capacity (350 mAh g−1 at 50 mA g−1) and reversibility (99.2% Coulombic efficiency), and it delivers a reversible specific capacity of 133 mAh g−1 at 2000 mA g−1 which is superior to the high‐rate performance typically reported for graphite. In situ studies provide insights into the mechanism of (de)lithiation, confirming the reduction of Sn(IV) to metallic Sn and the subsequent formation of Li‐Sn alloys, while the residual MAX remains electrochemically inactive, preserving structural integrity and transport properties. Controlled oxidation of Ti3Al0.3Sn0.7C2 produces SnO2/TiO2–MAX nanocomposites with superior electrochemical performance. The SnHigh_Ox700 sample shows optimal stability, capacity (300 mAh g−1), and reversibility (99.2%). Its unique morphology ensures efficient charge transport and stress accommodation. In situ analyses reveal reversible SnO2 conversion/alloying, while MAX cores stabilize cycling, enabling strong full‐cell performance versus graphite.

The galvanostatic electrodeposition of zinc on carbon paper from mildly acidic solutions (ZnCl2: 0.05–0.1 M; H3BO3: 0.05 M) was investigated. The deposits’ growth mechanisms were analyzed through the study of the electrodeposition potential transients and the physical characterization of the electrodes synthesized by varying the current density, transferred charge, and zinc precursor concentration. The analysis reveals that the transition from crystalline to amorphous mossy deposits takes place via the electrodeposition of metallic zinc followed by the formation of oxidized zinc structures. The time required for this transition can be controlled by varying the zinc precursor concentration and electrodeposition current density, allowing for the synthesis of composite zinc/oxidized zinc electrodes with varying ratios of the oxidized to underlying metallic phases. The impact of this ratio on the electrode activity for CO2 electroreduction is analyzed, highlighting that composite zinc/oxidized zinc electrodes can achieve a faradaic efficiency to CO equal to 82% at −1.8 V vs. Ag/AgCl. The mechanisms behind the variations in the catalytic activity with varying morphologies and structures are discussed, providing guidelines for the synthesis of composite zinc/oxidized zinc electrodes for CO2 electroreduction.

Electrodeposition from ZnCl2 aqueous solution was performed to grow ZnO thin films on the surface of polycrystalline copper plates. Electrochemical parameters for deposition were optimized by means of cyclic voltammetry (CV). The morphology of the deposits was studied via scanning electron microscopy (SEM), and their chemical composition was ascertained by means of X-ray photoelectron spectroscopy (XPS). The effects of changing the deposition bath temperature (Tbath) and the role played by post-deposition treatments, such as temperature and time of annealing in air, were studied. SEM images of freshly deposited vs. annealed samples have shown that in the former case the films display a rough morphology with mixed grain/hexagonal platelets structures and in the latter smaller but more uniformly dispersed cubic grains. Tbath is found to be the key parameter to induce the different morphology in the deposited films, which reflects in a different chemical reactivity of surface species, as found on the basis of the binding energies and relative quantitative ratios between Zn 2p and O 1s peaks. In fact, a higher Tbath favours a more efficient desorption of OH groups upon annealing, the O 1s peak resulting to much more drastically modified oxide/hydroxide intensity ratio with respect to the case of the sample deposited at lower Tbath.

The galvanostatic electrodeposition of zinc on carbon paper from mildly acidic solutions (ZnCl : 0.05-0.1 M; H BO : 0.05 M) was investigated. The deposits' growth mechanisms were analyzed through the study of the electrodeposition potential transients and the physical characterization of the electrodes synthesized by varying the current density, transferred charge, and zinc precursor concentration. The analysis reveals that the transition from crystalline to amorphous mossy deposits takes place via the electrodeposition of metallic zinc followed by the formation of oxidized zinc structures. The time required for this transition can be controlled by varying the zinc precursor concentration and electrodeposition current density, allowing for the synthesis of composite zinc/oxidized zinc electrodes with varying ratios of the oxidized to underlying metallic phases. The impact of this ratio on the electrode activity for CO electroreduction is analyzed, highlighting that composite zinc/oxidized zinc electrodes can achieve a faradaic efficiency to CO equal to 82% at -1.8 V vs. Ag/AgCl. The mechanisms behind the variations in the catalytic activity with varying morphologies and structures are discussed, providing guidelines for the synthesis of composite zinc/oxidized zinc electrodes for CO electroreduction.

The galvanostatic electrodeposition of zinc on carbon paper from mildly acidic solutions (ZnCl[sub.2]: 0.05–0.1 M; H[sub.3]BO[sub.3]: 0.05 M) was investigated. The deposits’ growth mechanisms were analyzed through the study of the electrodeposition potential transients and the physical characterization of the electrodes synthesized by varying the current density, transferred charge, and zinc precursor concentration. The analysis reveals that the transition from crystalline to amorphous mossy deposits takes place via the electrodeposition of metallic zinc followed by the formation of oxidized zinc structures. The time required for this transition can be controlled by varying the zinc precursor concentration and electrodeposition current density, allowing for the synthesis of composite zinc/oxidized zinc electrodes with varying ratios of the oxidized to underlying metallic phases. The impact of this ratio on the electrode activity for CO[sub.2] electroreduction is analyzed, highlighting that composite zinc/oxidized zinc electrodes can achieve a faradaic efficiency to CO equal to 82% at −1.8 V vs. Ag/AgCl. The mechanisms behind the variations in the catalytic activity with varying morphologies and structures are discussed, providing guidelines for the synthesis of composite zinc/oxidized zinc electrodes for CO[sub.2] electroreduction.

Osteoarthritis (OA) is a prevalent chronic pain syndrome and a leading cause of disability worldwide, characterized by progressive deterioration of articular cartilage. This degradation leads to pain, swelling, inflammation, and eventual stiffness as the cartilage wears down, causing bone-on-bone friction. Current medical treatments primarily aim at pain relief; however, many interventions, especially invasive or surgical ones, carry risks of adverse outcomes. Consequently, intra-articular (IA) therapy, particularly hyaluronic acid (HA) injections, is widely adopted as a conservative treatment option. HA plays a crucial role in maintaining joint homeostasis by supporting proteoglycan synthesis and scaffolding, restoring optimal HA concentrations in synovial fluid, and providing chondroprotective and anti-inflammatory effects. In recent years, hydrogels composed of natural and synthetic materials have emerged as promising candidates for OA treatment. Our research focuses on the biosynthesis and characterization of novel hydrogel composites combining short peptide hydrogelators with aminated graphene oxide (a-GO) nanosheets functionalized with HA (a-GO-HA@Hgel). These a-GO-HA@Hgel nanocomposites are designed to facilitate the controlled release of HA into the extracellular matrix, aiming to promote cartilage regeneration and mitigate inflammation. The strategy is to exploit the oxygen-containing functional groups of GO nanosheets to enable covalent coupling or physical adsorption of HA molecules through various chemical approaches. The resulting a-GO-HA are incorporated within hydrogel matrices to achieve sustained and controlled HA release. We study the influence of a-GO-HA on the native hydrogel structure and its viscoelastic properties, which are critical for mimicking the mechanical environment of native cartilage tissue. Through this multidisciplinary approach combining advanced materials science and cellular biology, this work aims to develop innovative nanocomposite hydrogels capable of delivering HA in a controlled manner, enhancing cartilage repair and providing a potential therapeutic strategy for OA management.