Selective removal of copper (II) ions from aqueous solution using pyridyl-bridged mesoporous organosilica hybrid adsorbent.

The incorporation of active functional groups into the mesoporous organosilica hybrid materials is efficient for various applications. A newly designed mesoporous organosilica adsorbent was prepared using diaminopyridyl groups bridged-(bis-trimethoxy)organosilane (DAPy) precursor by using Pluronic P123 as structure directing template via sol-gel co-condensation method. The hydrolysis reaction of DAPy precursor and tetraethyl orthosilacate (TEOS) with a DAPy content of about 20 mol% to TEOS were incorporated into the mesopore walls of the mesoporous organosilica hybrid nanoparticles (DAPy@MSA NPs). Low-angle XRD and FT-IR, N2 adsorption-desorption analysis, SEM, TEM, and TG analysis were used to characterize the synthesized DAPy@MSA NPs. The DAPy@MSA NPs exhibit an order mesoporous structure with a high surface area, mesopore size and pore volume of approximately ∼465 m2/g, 4.4 nm and 0.48 cm3/g, respectively. The pyridyl groups integrated DAPy@MSA NPs showed the selective adsorption of Cu2+ ions from the aqueous medium by metal-ligand complex coordination of Cu2+ ions with the integrated pyridyl groups and the pendant hydroxyl (-OH) functional groups present into the mesopore walls of the DAPy@MSA NPs. In the presence of other competitive metal ions (Cr2+, Cd2+, Ni2+, Zn2+, and Fe2+), the DAPy@MSA NPs showed relatively high adsorption of Cu2+ ions (276 mg/g) from aqueous solution as compared to the other competitive metal ions at the same concentration (100 mg/L) of initial metal ion solution.

Magnetic Application of Gadolinium Orthoferrite Nanoparticles Synthesized by Sol-Gel Auto-Combustion Method.

In this manuscript, we present the synthesis of gadolinium orthoferrite nanoparticles using the sol-gel auto-combustion technique. The obtained gadolinium orthoferrite nanoparticles were annealed at various temperatures, such as 800 °C, 900 °C, 1000 °C, and 1100 °C. The synthesized materials were analyzed by various instrumental characterizations. The vibrational characteristics of the synthesized samples were verified by FTIR. The surface morphology of the gadolinium orthoferrite nanoparticles was analyzed by FE-SEM and HR-TEM, revealing their spherical structural morphology and uniform particle structure. The presence of the elemental features was analyzed in the gadolinium orthoferrite nanoparticles by EDAX. The surface analysis of the core ranges of the XPS-recorded spectra were obtained for the elemental states of the Gd, Fe, and O factors in the samples, and it additionally characterized the different levels of oxidative states by fitting the levels of the high-resolution parameters of Gd 4d, Fe 2p, and O 1s. The magnetic properties of the samples were investigated by VSM. The measurement of the magnetic parameters revealed that gadolinium orthoferrite nanoparticles exhibit a ferromagnetic nature.