In the present study, Cu(ii) immobilized on an Fe3O4@HNTs–tetrazole (CFHT) nanocomposite was designed and prepared.

In this study, halloysite nanotubes (HNTs) are modified by chitosan as a natural cationic amino polysaccharide. Halloysite nanotubes/chitosan (HNTs/Chit) were characterized by Fourier transform infrared (FT-IR) spectroscopy and energy dispersive X-ray (EDX) analysis. Also, its performance as a heterogeneous catalyst was investigated in the synthesis of pyranopyrazole derivatives. Being a reusable and easily recoverable catalyst, eco-friendliness, high efficiency, and mild reaction conditions are some advantages of the present work.

A magnetic hybrid nanoabsorbent made of iron oxide, halloysite and polystyrene is fabricated and utilized for the absorption of X-band microwaves.