Enhanced oxidative degradation of 2,4-dichlorophenol by iron oxychloride supported on graphitic carbon nitride via peroxymonosulfate activation: Significant role of Fe(II)/Fe(III) conversion cycle.

The activation of peroxymonosulfate (PMS) by heterogeneous catalysts presents an exciting but challenging strategy for degrading persistent organic pollutants in water. Iron oxychloride (FeOCl) is considered a promising heterogeneous catalyst due to its unique oxygen bridge structure, which could render it more active by facilitating the iron valence transitions between Fe(II) and Fe(III). However, the limited Fe(II)/Fe(III) conversion cycle rate hinders its catalytic activity, leading to unsatisfactory PMS activations in practical applications.

Mechanism of nitrogen-doped biochar activated peroxymonosulfate for degradation of 2,4-dichlorophenol.

Biochar activated peroxymonosulfate has been widely used to degrade organic pollutants. However, the chemical inertness of the sp2 hybrid conjugated carbon framework and the limited number of active sites on the pristine biochar resulted in the low catalytic activity of the system, restricting its further application. In this study, nitrogen-doped biochar was prepared following a simple one-step synthesis method taking advantage of the similar atomic radius and significant difference in electronegativity of N and C atoms to explore the properties and mechanisms of biochar-mediated peroxymonosulfate activation to degrade 2,4-dichlorophenol.

Enhanced Biotribological and Anticorrosion Properties and Bioactivity of Ti6Al4V Alloys with Laser Texturing.

The poor biotribological properties and bioinertness of Ti6Al4V have restricted its application in biomedical materials. In this study, microgrooves of different widths were prepared on the surface of a Ti6Al4V alloy by laser treatment. The tribological properties under dry lubrication and simulated body fluid (SBF) lubrication conditions, the electrochemical corrosion properties in SBF solution, and the bone marrow mesenchymal stem cell (BMSC) behavior on the surfaces were systematically tested.

Tribological Performance of an Imidazolium Ionic Liquid-Functionalized SiO@Graphene Oxide as an Additive.

A graphene oxide (GO)-wrapped SiO nanosphere was modified with a 1-methylimidazolium bis(salicylato)borate (MEIMBScB) ionic liquid to form a SiO@GO@MEIMBScB nanocomposite. The SiO@GO@MEIMBScB nanocomposite exhibited a core-shell structure, which was characterized by Fourier transform infrared spectroscopy, ultraviolet-visible spectroscopy, photoluminescence spectroscopy, dynamic light scattering, X-ray photoelectron spectroscopy, scanning electron microscopy, and transmission electron microscopy. The SiO@GO@MEIMBScB nanocomposite was dispersed into poly(ethylene glycol) 400 (PEG400) as a lubricant additive, and its tribological performance was evaluated with a four-ball tribometer under 392 N at 1450 rpm for 30 min.

The Tribological Properties of Reduced Graphene Oxide Doped by N and B Species with Different Configurations.

Reduced graphene oxide (rGO) was doped by nitrogen (N) and/or boron (B), leading to four different configurations: N-rGO (N-doped rGO), B-rGO (B-doped rGO), N-B-rGO (N and B codoped rGO with formation of B-N bond), and N,B-rGO (N and B isolate-doped rGO without formation of B-N bond). The preparations of different configurations were controlled by the chemical vapor deposition procedure, and their structures were further confirmed by Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and X-ray diffraction (XRD). The tribological performance of these was tested via a ball-on-flat tribometer under 5 N load.

Asymmetric aldol reactions catalyzed by efficient and recyclable silica-supported proline-based peptides.

A series of silica-supported proline-based peptides were synthesized and applied as catalysts for direct asymmetric intermolecular aldol reactions. Among these, a peptide with two L-proline units was found to be the most efficient one for the asymmetric aldol reactions between acetone and aromatic aldehydes. The reactions generated the corresponding products with satisfactory isolated yields (up to 97%) and enantiomeric excesses (up to 96%) in the presence of this catalyst (5 mol %).