Ni-SMTU@boehmite: as an efficient and recyclable nanocatalyst for oxidation reactions

Boehmite nanoparticles were prepared via a simple and inexpensive procedure in water using commercially available materials, and furthermore a novel type of recoverable nanocatalyst was prepared via immobilization of the S-methylisothiourea complex of nickel on the surface of boehmite nanoparticles (Ni-SMTU@boehmite). This organometallic catalyst was characterized by FT-IR spectroscopy, TGA, XRD, ICP-OES, EDS and SEM techniques. Ni-SMTU@boehmite was applied as an efficient, recoverable and stable heterogeneous organometallic catalyst for the selective oxidation of sulfides to sulfoxides and oxidative coupling of thiols to corresponding disulfides. Metal leaching and heterogeneity test of this catalyst was examined by the ICP-OES technique, which showed that this catalyst can be recovered and reused for several times without significant loss of its catalytic efficiency or nickel leaching.