Functionalized Ni nanoparticles synthesized using electroless plating waste. Characterization and possible application as methylene blue adsorbent

Abstract

This study investigates the reuse of industrial residue to synthesize magnetic nickel nanoparticles functionalized with sodium dodecyl sulfate (Ni-NPs/SDS). Two synthesis routes were tested: Route 1 involved in situ functionalization during nickel recovery (RHS sample), while Route 2 included separate oxidation and functionalization steps after nanoparticle synthesis (RHoxS sample). The Ni particles showed spherical morphology and crystallite sizes of 8 – 11 nm. Functionalized particles had slightly larger sizes (10 – 15 nm) and irregular, spiky surfaces, more evident in RHoxS. The ferromagnetic character was reduced in functionalized samples, and all exhibited negative zeta potential values below 30 mV.A preliminary methylene blue (MB) adsorption study with RHoxS showed effective functionalization. Batch tests at room temperature fit better to the Freundlich isotherm model (R2 = 0.9633), suggesting a heterogeneous surface and a physical adsorption process. The Langmuir isotherm model estimates a maximum capacity of adsorption of 5.51 mg.g-1, indicating the material’s potential for wastewater dye removal.