Publications

This study explores the impact of incorporating a small quantity of conductive boron-doped diamond powder (BDDP) into cobalt oxide-based electrocatalysts prepared via solution combustion, aiming to improve their performance in both the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR). Structural analyses using X-ray diffraction and Raman spectroscopy identify Co3O4 as the primary phase, unaffected by the presence of BDDP. In contrast, X-ray photoelectron spectroscopy reveals that adding BDDP promotes the formation of additional CoO species and enhances surface levels of Co(OH)2, oxygen vacancies, adsorbed hydroxyl groups, and water, features that are beneficial for oxygen electrocatalysis. Electrochemical testing demonstrates that the Co3O4-BDDP catalyst delivers markedly enhanced OER activity, including a decrease in Tafel slope of about 15% at lower applied potentials and up to 30% at higher ones, along with almost a doubling of the turnover frequency. For ORR, the inclusion of BDDP leads to nearly a fourfold rise in reduction current at-0.36 V. Furthermore, the comparable Tafel slopes for OER and ORR suggest efficient kinetics in both directions, underscoring the promise of Co3O4-BDDP catalysts for applications in rechargeable metal-air batteries and unitized regenerative fuel cells.

This paper reports about bulk heterojunctions layers containing azomethine oligomers based on carbazole (AzC) or triphenylamine (AzPA) donor and alkyl perylene diimide derivative (PTCDI-12C) acceptor blended in different weight ratios (1:2), (1:3) and (1:4), prepared by Matrix Assisted Pulsed Laser Evaporation (MAPLE) on flexible substrate of polyethylene terephthalate (PET) covered by ITO. The effect of the type of azomethine donor substituent group and mixed layer composition on the optical and electrical properties was investigated in correlation with the molecular aggregation particularities and surface topographical particularities of the layers.The strong absorption band between 400 and 650 nm was favored by the strong polarization interactions in the layers deposited by MAPLE from chloroform and the red shift of the UV-Vis absorption peaks of PTCDI-12C in the both types of bulk heterojunction layer confirmed the generation during the deposition mostly of J-aggregates, which are associated with the fluorescence emission.The correlation between the roughness, statistical analysis parameters obtained by height-to-height correlation function, grains shape and electrical behavior was analyzed. The samples prepared with AzC donor showed photoelectric behavior with the best parameters for AzC:PTCDI-12C in a weight ratio of (1:3), while the sample with AzPA:PTCDI-12C mixed layer showed an injection contact behavior with the best current (10(-4) A for voltage < 0.5 V) at a weight ratio of (1:2). Thus, the behavior of the heterostructures is affected by the type of azomethine: carbazole-azomethine can be potential candidates for optoelectronic applications while triphenylamine-azomethine for electronic application.[GRAPHICS].

This paper summarises the progress in characterisation of the CuCrZr alloy selected for the cooling pipes of European DEMO divertor achieved by several laboratories within EUROfusion in the frame of a large experimental campaign. Since the high-temperature hot radial pressing (HRP) joining procedure will modify the material properties, the CuCrZr alloy has been tested after an HRP-simulating heat treatment to represent a DEMO-relevant material. The ongoing characterization campaign is filling gaps of mechanical and thermophysical properties in the current MPH version which contains limited information on CuCrZr after the relevant thermal treatment, and helps reduce unnecessary conservatism of divertor design. Neutron irradiation campaign is ongoing which will provide high-priority mechanical properties at high dose (1-9 dpa). The obtained material properties will be compiled in the DEMO Material Property Handbooks (MPH), which will be used by the DEMO divertor design team. Most of the scheduled high-priority mechanical and thermophysical tests have been completed on non-irradiated material, their results are presented and compared to the data from the DEMO CuCrZr MPH.

The kidney is a major organ for xenobiotic detoxification and a primary target for nanoparticle (NPs)-induced toxicity. This study investigated oxidative stress responses and renal histopathological alterations in Helix aspersa after dietary exposure to nickel oxide (NiO), magnesium oxide (MgO), and their composite (NiO-MgO) nanoparticles. Snails were fed two NPs concentrations (1 and 2 mg. g(-1) feed) for four weeks. Oxidative stress was evaluated through the biomarkers glutathione (GSH), glutathione peroxidase (GPX), glutathione S-transferase (GST), and catalase (CAT), supported by multivariate statistics, response surface modeling (RSM), and interaction energy analysis. All treated groups exhibited statistically significant oxidative alterations (p individual NPs. RSM revealed nonlinear, nanoparticle-specific effects: GSH showed strong synergism, GPX mild synergy, while GST and CAT displayed antagonistic behavior. Further modeling using the Interaction-Based Hypothesis (IBH) framework linked response surface coefficients to molecular binding affinities, showing strong molecular interactions for GST (-8.3 kcal mol(-)(1)) and CAT (-8.0 kcal mol(-)(1)), consistent with observed enzyme inhibition. Histopathological assessments confirmed progressive renal lesions aligned with biochemical responses. Overall, these findings demonstrate that NiO and MgO nanoparticles impair renal antioxidant defense in H. aspersa through complex non-additive interactions. The integrated methodological framework bridges biochemical and molecular levels, highlighting ecological and food safety concerns associated with terrestrial nanoparticle contamination.

Composites based on TiO2 and single-walled carbon nanotubes (SWCNTs), highly separated in semiconducting tubes (S-SWCNTs) and as a mixture of metallic and semiconducting tubes (M + S-SWCNTs), were obtained by the interaction in the solid state. This interaction induces a change in the size of TiO2 particles from 23.67 nm to 28.2 and 150 nm, respectively, accompanied by an increase in the disorder state of the graphitic lattice of SWCNTs. We demonstrate by UV-VIS spectroscopy that the best performance in terms of rhodamine 6G (Rh6G) photodegradation is obtained in the case of the TiO2/S-SWCNT composite. The highest values of the Rh6G photodegradation efficiency were equal to 92% for an S-SWCNT concentration in the photocatalyst mass of 10 wt% and 94% for a 0.1 mM Rh6G solution with a pH equal to 1. We demonstrate that an important role is played by the O2(center dot)- and (OH)-O-center dot species in the photodegradation mechanism of Rh6G. This study contributes to a better understanding of the role of metallic and semiconducting carbon nanotubes in the photocatalysis field, highlighting that composites based on semiconducting SWCNTs and semiconducting metallic oxides are those that contribute essentially to the removal of dyes by exposure to the light emitted by a halogen lamp.

We consider random sequential adsorption (RSA) of aligned squares and derive the low-coverage expansion of the availability function alpha(q), the fraction of positions accessible to an additional square, up to fourth order in the coverage q. At low coverage, the reduction of available space can be understood in terms of geometric overlap between exclusion regions created by previously deposited squares. A single square blocks a finite area; pairs of squares may have overlapping exclusion zones, reducing the total blocked area; similarly, three and four squares can share a common overlap region, leading to higher-order corrections. These contributions can be systematically accounted for through an inclusion-exclusion expansion based on the geometry of overlapping exclusion regions, with alternating signs dictated by inclusion-exclusion. The expansion terminates exactly at fourth order, since no more than four deposited squares can simultaneously overlap the exclusion region of a trial insertion. The coefficients are obtained by explicit enumeration of all such geometrically admissible configurations and are further confirmed by numerical simulations on a discrete lattice, showing agreement within statistical uncertainty.

Water pollution poses a major threat to environmental sustainability and human health. Here, we report novel 4'aminobenzo-15-crown-5 ether-functionalized hydrochars as eco-friendly adsorbents for the removal of copper and lead ions from water. The hybrid materials were synthesized via a carbohydrate-assisted hydrothermal route using sucrose, starch, and fructose as carbon sources. Pristine and functionalized hydrochars were characterized by various techniques, including scanning electron microscopy (SEM), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), thermal analysis (TG/DTG/DTA) and X-ray photoelectron spectroscopy (XPS). The crown ether functionalization and materials integrity were successfully confirmed. Batch adsorption measurements for Cu2+ and Pb2+ removal from aqueous solutions demonstrated that the Freundlich isotherm provided the best fit, suggesting multilayer and heterogeneous adsorption. The adsorption capacities ranged from 10.15 to 16.86 mg center dot g-1 for Cu2+ and from 8 to 11.93 mg center dot g-1 for Pb2+, indicating their potential as sustainable materials for mitigating water pollution.

Optimizing the interfaces in perovskite solar cells (PSCs) is essential for enhancing their performance, improving their stability, and making them commercially viable for large-scale deployment in solar energy harvesting applications. Point defects, like vacancies, have a dual role, as they can inherently provide a proper doping, but they can also reduce the collected current by trap-assisted recombination. Moreover, they can play an active role in ion migration and degradation. Using ab initio density functional theory calculations we investigate the changes in the band alignment induced by interfacial vacancy defects in a TiO 2/MAPI/Cu 2O based PSC. Depending on the type of the vacancy (Ti, Cu, O, Pb, I) in the oxide and perovskite materials, additional doping is superimposed on the already existing background. Their effect on the performance of the PSCs becomes visible, as shown by SCAPS simulations. The most significant impact is observed for p type doping of TiO 2 and n type doping of Cu 2O, while the effective doping of the perovskite layer affects one of the two interfaces. We discuss these results based on modifications of the band structure near the active interfaces and provide further insights concerning the optimization of electron and hole collection.

Using solid-state interactions, composites based on molybdenum disulfide (MoS2), poly(ortho-toluidine) (POT), and reduced graphene oxide (RGO) were prepared. Raman scattering and FTIR spectroscopic studies have demonstrated that the interaction of the RGO and MoS2 sheets with the POT-emeraldine base state (EB) leads to composites composed of RGO sheets non-covalently functionalized with pseudo-protonic POT doped with MoS2 and RGO covalently functionalized with POT-leucoemeraldine salt (LS). An alternative way to prepare these composites is the solid-state interaction of the RGO and MoS2 sheets with the POT-emeraldine salt (ES), resulting in composites composed of RGO non-covalently functionalized with POT-salt having pseudo-protonic acidic entities doped with MoS2 and RGO covalently functionalized with POT-leucoemeraldine base (LB). Using UV-Vis spectroscopy, we demonstrate that the exposure of these composites to UV light in protic polar solvents leads to the generation of partially de-doped POT-LB and POT-ES. The features of the composites after light exposure, as well as their transformation to the salt state, are highlighted by surface-enhanced Raman scattering. This study contributes to better understanding of the properties of the composites based on MoS2, POT, and RGO, highlighting the need to avoid the exposure of composites dissolved in polar protic solvents to UV light.

Strain engineering is an effective strategy to tune the electronic structure and catalytic performance of functional materials. Here, we demonstrate a single-step continuous hydrothermal flow synthesis (CHFS) that produces multiphase titanate-TiO2-reduced graphene oxide (rGO) nanocomposites capable of both photocatalytic and mechanocatalytic activity. In this approach, in situ KOH-mediated reduction of graphene oxide introduces interfacial lattice strain and directs the co-crystallisation of anatase TiO2, layered K2Ti4O9, and metastable TiO2(B). The resulting multiphase composites feature strain gradients and nanoscale heterojunctions that enhance visible-light absorption, charge separation, and mechanically assisted catalytic response. Density functional theory (DFT) simulations confirm strain-induced bandgap narrowing and charge redistribution at oxide-2D interfaces. Under simultaneous visible-light irradiation and mechanical stirring, these hybrids achieved near-complete degradation of concentrated aqueous methylene blue (0.04 mM) within 60 min, with an apparent dual-mode rate constant of 0.1046 min-1, outperforming conventional photocatalysts. This single-step, scalable platform provides a general route to design multifunctional catalysts for environmental remediation and solar-to-chemical energy conversion.