Experimental and theoretical investigations of novel synthesized organo-silane compounds and modified mesoporous silica materials

Hybrid silica nanoparticles functionalized with pyrazolone-tethered organosilane: Synthesis and application for Sn (II) ion sensing in tap water

Pyrazolone tethered triazole functionalized organosilane and their hybrid silica nanoparticles (HSNPs) have been synthesised for the selective detection of Sn(II) using spectrophotometric techniques. The prepared compounds are characterized by FT-IR, NMR (1H and 13C), XRD, mass spectrometry and FE-SEM spectral analyses. The synthesized hybrid silica nanoparticles gave improved detection limit of 4.3 × 10-8 M and stoichiometry of complex between analyte and probe was found to be 1:1. The association constant calculated for organosilane and their HSNPs came out to be 9.54 × 104 M-1 and 7.47 × 104 M-1 while the presence of other ions showed no interference in the sensing behaviour. The results of the use of this sensing system in tap water facilitate its applicability in real samples with the recovery % more than 98.

First-principles study of two-dimensional half-metallic ferromagnetism in CrSiSe4monolayer

Two-dimensional (2D) ferromagnetic (FM) half-metallic materials have attracted intensive attention due to their unique electronic and magnetic properties and potential applications in spintronic devices. In this study, we predicted a stable 2D half-metallic material monolayer CrSiSe4using first-principles density functional theory. The structure, electronic and magnetic properties were systematically studied. The calculations show that the monolayer CrSiSe4is a dynamically stable FM half-metallic material. The spin-dependent transport properties and the Curie temperature up to 239 K are demonstrated. The spin band gap of monolayer CrSiSe4was about 0.83 eV by the the Heyd-Scuseria-Ernzerhof function calculation. The magnetic anisotropy energy of each Cr atom in the monolayer of CrSiSe4is-552.3μeV. When the applied biaxial tensile strain is greater than 2%, monolayer CrSiSe4spin-up conduction band and valence band will show a band gap at the Fermi level, and the electronic properties change from a half-metal to a semiconductor. Thus, the monolayer CrSiSe4can provide an ideal candidate material for exploring 2D magnetic and spintronics experiments.

Magnetic poly-o-vanillin-functionalized core–shell nanomaterials as a smart sorbent for scavenging mercury(ii) from aqueous solution

In the present work, a poly-o-vanillin-functionalized magnetic nanoparticle of PoVan/CoFe₂O₄@mSiO₂ with core–shell structure was synthesized through a facile, green and low cost method.