The successful synthesis of biguanide-functionalized mesoporous silica catalysts: Excellent reactivity combined with facile catalyst recyclability

Tungstate supported mesoporous silica SBA‐15 with imidazolium framework as a hybrid nanocatalyst for selective oxidation of sulfides in the presence of hydrogen peroxide

“…As can be seen, the typical silica bands associated with the main inorganic backbone can be clearly observed in both spectra. The sharp band in curve (a) at 1079 cm −1 corresponde to Si‐O‐Si anti‐symmetric stretching vibration, being indicative of the existence of a silica material, and the signal that appeared at ~3400 cm −1 can be assigned to the O‐H stretching frequency of Si‐O‐H groups . The signal that appeared at 1618 cm −1 can be attributed to the presence of C = N stretching vibration.…”

Simultaneous determination of ultra-low traces of lead and cadmium in food and environmental samples using dispersive solid-phase extraction (DSPE) combined with ultrasound-assisted emulsification microextraction based on the solidification of floating organic drop (UAEME-SFO) followed by GFAAS

“…The synthesis of SBA-15 was performed following a well-known procedure. 19,20 In short explanation for the SBA-15 synthesis, 4.0 g of pluronic P123 was dissolved in 50 mL of water and stirred for 5 h at room temperature. The mixture was added to 120 mL of 2 mol L À1 hydrochloric acid solution and remained for 2 h. Then, 8.5 g of TEOS was added to that solution and stirred for 24 h at 35 C. The mixture was then aged at 80 C for 24 h without stirring.…”

“…In order to examine the effect of the volume of the extraction solvent on the performance of the presented UAEME procedure, different volumes of 1-undecanol (20,30,40,50, 60, 80 mL) were used. By increasing the volume of 1-undecanol from 20 to 80 mL, the volume of the oating organic drop increases from 16 to 74 mL.…”

Immobilized Pd on (S)‐methyl histidinate‐modified multi‐walled carbon nanotubes: a powerful and recyclable catalyst for Mizoroki–Heck and Suzuki–Miyaura C–C cross‐coupling reactions in green solvents and under mild conditions

“…However, the preparation of most reported ligands seems rather laborious and time‐consuming. Therefore, employing available biomolecules such as amino acids, alkaloids and nucleic acids and supporting them on solid substrates is highly favorable . Among them, histidine is an applicable amino acid in catalytic systems, its key features including air‐stability, low cost, nontoxicity and easy accessibility (via chemical synthesis) that make it a more efficient ligand or nanometal species stabilizer for practical applications compared with other well‐established ligands …”