One-pot green bio-assisted synthesis of highly active catalytic palladium nanoparticles in porcine gastric mucin for environmental applications

In this work, palladium nanoparticles were synthesized using one-pot synthesis utilizing porcine gastric mucin glycoproteins as reducing and capping agents. It is shown that the particles exhibited noticeable catalytic activity through both nitrophenol reduction and Suzuki-Miyaura coupling reactions. The catalytic performance was demonstrated with exceptionally high product yield, a fast reaction rate, and low catalyst use. The palladium-mucin composites obtained could be used in particle solution and as hydrogel catalysts to increase their reusability for at least ten reaction cycles with minimum loss in their catalytic effectiveness.

Synthesis of Ni-Ag-ZnO solid solution nanoparticles for photoreduction and antimicrobial applications

ZnO is one of the most promising and efficient semiconductor materials for various light-harvesting applications. Herein, we reported the tuning of optical properties of ZnO nanoparticles (NPs) by co-incorporation of Ni and Ag ions in the ZnO lattice. A sonochemical approach was used to synthesize pure ZnO NPs, Ni-ZnO, Ag-ZnO and Ag/Ni-ZnO with different concentrations of Ni and Ag (0.5%, 2%, 4%, 8%, and 15%) and Ni doped Ag-ZnO solid solutions with 0.25%, 0.5%, and 5% Ni ions. The as-synthesized Ni-Ag-ZnO solid solution NPs were characterized by powdered X-ray diffraction (pXRD), FT-IR spectroscopy, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), UV-vis (UV) spectroscopy, and photoluminescence (PL) spectroscopy. Ni-Ag co-incorporation into a ZnO lattice reduces charge recombination by inducing charge trap states between the valence and conduction bands of ZnO and interfacial transfer of electrons. The Ni doped Ag-ZnO solid solution NPs have shown superior 4-nitrophenol reduction compared to pure ZnO NPs which do not show this reaction. Furthermore, a methylene blue (MB) clock reaction was also performed. Antibacterial activity against E. coli and S. aureus has inhibited the growth pattern of both strains depending on the concentration of catalysts.

A novel Au/electroactive poly(amic acid) composite as an effective catalyst for p-nitrophenol reduction

A Au/electroactive poly(amic acid) (Au/EPAA) composite was synthesized and characterized, and its catalytic ability was evaluated. EPAA was synthesized via oxidative coupling polymerization and Au nanoparticles were anchored to the amino and carboxyl groups. The Au/EPAA composite was characterized via X-ray diffraction analysis, X-ray photoelectron spectroscopy, and scanning electron microscopy, which confirmed that the Au nanoparticles were well dispersed on the EPAA surface. p-Nitrophenol was reduced to p-aminophenol within 5 min at room temperature, with a rate constant of 0.84 min⁻¹. Cycling measurements showed that the Au/EPAA composite achieved higher than 92% conversion. The Au/EPAA composite showed excellent performance and stability as a catalyst for the reduction of p-nitrophenol to p-aminophenol.

The Au/EPAA composite demonstrated excellent performance and stability as a catalyst for the reduction of p-nitrophenol to p-aminophenol.

From coordination polymers to nanocrystals: general and facile synthesis of ultra-small metal oxide nanocrystals

Ultrasmall and well-dispersed ZnO QDs with special optical properties and polymerization activity were synthesised by using coordination polymers as templates.