Ampholyte polystyrene spheres self-regulated deposition of noble metal nanoparticles for catalyst applications

A protector-free one-pot strategy to synthesize highly dispersed Pd hydrogenation catalysts in a broad loading range on polystyrene

Pd nanocatalysts in desired size range (ca. 3.0–5.0 nm) and clean state (protector-free) were feasibly prepared in one-pot system by a surface electrostatic manipulation on polystyrene in broad loading (0.2–4.6 wt%).

Investigating the Dispersion Behavior in Solvents, Biocompatibility, and Use as Support for Highly Efficient Metal Catalysts of Exfoliated Graphitic Carbon Nitride

The liquid-phase exfoliation of graphitic carbon nitride (g-C3N4) to afford colloidal dispersions of two-dimensional flakes constitutes an attractive route to facilitate the processing and implementation of this novel material toward different technological applications, but quantitative knowledge about its dispersibility in solvents is lacking. Here, we investigate the dispersion behavior of exfoliated g-C3N4 in a wide range of solvents and evaluate the obtained results on the basis of solvent surface energy and Hildebrand/Hansen solubility parameters. Estimates of the three Hansen parameters for exfoliated g-C3N4 from the experimentally derived data yielded δD ≈ 17.8 MPa(1/2), δP ≈ 10.8 MPa(1/2), and δH ≈ 15.4 MPa(1/2). The relatively high δH value suggested that, contrary to the case of other two-dimensional materials (e.g., graphene or transition metal dichalcogenides), hydrogen-bonding plays a substantial role in the efficient interaction, and thus dispersibility, of exfoliated g-C3N4 with solvents. Such an outcome was attributed to a high density of primary and/or secondary amines in the material, the presence of which was associated with incomplete condensation of the structure. Furthermore, cell proliferation tests carried out on thin films of exfoliated g-C3N4 using murine fibroblasts suggested that this material is highly biocompatible and noncytotoxic. Finally, the exfoliated g-C3N4 flakes were used as supports in the synthesis of Pd nanoparticles, and the resulting hybrids exhibited an exceptional catalytic activity in the reduction of nitroarenes.

Highly facile and efficient assembly of palladium nanoparticles on polystyrene microspheres and their application in catalysis

Herein we develop a facile and effective strategy for the synthesis of composite particles composed of polystyrene microspheres decorated with palladium nanoparticles, which exhibited excellent catalytic activity and stability towards the reduction of p-nitrophenol by NaBH₄.