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This study introduces novel core-shell structured electrocatalysts synthesized via an optimized one-pot sol-gel method, aimed at enhancing the efficiency of the Hydrogen Evolution Reaction (HER) in water splitting. The Ni–NiO/TiO 2 and NiO/TiO 2 composites demonstrate superior catalytic performance, with the Ni–NiO/TiO 2 requiring a remarkably low potential of −0.125 V versus Ag/AgCl to achieve a current density of 10 mA.cm-2. This performance surpasses that of NiO/TiO 2 and pure NiO, offering a viable alternative to Pt catalysts. Advanced characterization techniques, including X-ray diffraction, electron microscopy, and X-ray photoelectron spectroscopy, elucidate the crystalline phases, morphologies, and chemical states, enhancing our understanding of the electrocatalysts' efficiency. In particular, Rietveld refinement analysis provides detailed insights into the structural properties that underpin the observed catalytic performance. Electrochemical assessments highlighted the Ni–NiO/TiO 2 composite's reduced overpotential needs, high Faradaic efficiency (∼98%), and notable long-term durability, positioning these materials as promising candidates for sustainable hydrogen production. [Display omitted] • Argon-induced Ni segregation enhances the NiO/TiO 2 catalytic activity for water splitting. • Achieved a low onset potential (∼88 mV) and a Tafel slope of 40 mV/dec. • Used Rietveld and XPS for catalyst characterization, elucidate the enhancing HER. • Demonstrated superior stability and ∼98% Faradaic efficiency over Pt catalysts. [ABSTRACT FROM AUTHOR]

A plasma-deposited coating, containing silver nanoparticles embedded in an organosilicon matrix, was synthesized, using AISI 316L stainless steel as the underlying substrate. The coating antibacterial property was evaluated on the Gram-negative Escherichia coli K12 MG1655 and the Gram-positive Staphylococcus aureus MW2 strains, by combining indirect (plate counting) and in situ (fluorescent bacteria labelling) methods. Both approaches were shown to be highly complementary and converged on a maximal antibacterial efficacy against E. coli , as plate counts showed a decrease of 6 and 1 Log and dead bacteria represented 25% and 2% of the total adhering bacteria for E. coli and S. aureus , respectively. The coating antibacterial potential was then determined over time on E. coli biofilm. Whatever the biofilm age, growth inhibition was observed due to silver-mediated bacteriostatic effect. The coating bactericidal activity was initially strong. However, differences between coated and bare stainless steel surfaces tended to collapse above a 2-day contact time. A thorough characterization of the film properties after ageing in biological suspension or saline solution (short and longer-term exposures) revealed an oxidation of both the organosilicon matrix and the silver nanoparticles, accompanied by silver release at the extreme surface. However, a silver reservoir was still present and potentially active in the deep layers of the coating. [ABSTRACT FROM AUTHOR]

Abstract: Thin films are deposited in a multipolar microwave plasma reactor excited by distributed electron cyclotron resonance (MMP–DECR) using Zirconium Tert-Butoxide (ZTB) as precursor and characterized in function of two process parameters: microwave power and ratio gas mixture (O2/ZTB+O2). Their influences on deposition rate, density, chemical bonds, atomic composition and microstructure of the deposits are presented: for pure ZTB plasma the films contain a high rate of hydrocarbon and their density is low (close to hydrogenated carbon film density). The study versus microwave power shows that film contains less hydrocarbon at high power than at low power but the addition of O2 to ZTB appears to be mainly responsible for hydrocarbon removal. Moreover microstructure analysis shows a columnar growth when a high amount of O2 (≥90%) is added in the gas mixture. [Copyright &y& Elsevier]