Adsorption of Au(III) by amino‐modified monodispersed PGMA microspheres and deposition of gold nanoparticles

Abstract

Abstract Monodispersed poly(glycidyl methacrylate) (PGMA) microspheres with various amounts of amino groups (PGMA‐NH 2 ) were used to adsorb Au(III) from simulated wastewaters. Gold nanoparticle‐coated PGMA functional microspheres can be directly obtained via the adsorption process. The adsorption kinetics follows pseudo‐second model, and 10 min is enough for reaching at equilibrium. The adsorption isotherm follows Langmuir model, and the adsorption amounts for Au(III) are 8.25 and 21.75 mol·kg −1 at 298 and 328 K, respectively. The relative separation coefficients between Au(III), Pt(VI), Pd(II) and Co(II), Cu(II), Ni(II), Fe(III) are all higher than 100 when 1 < pH < 3. Furthermore, the characterization analysis of X‐ray diffraction (XRD), thermogravimetry–differential scanning calorimetry (TG–DSC), scanning electron microscopy–energy dispersive spectroscopy (SEM–EDS), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR) confirms that AuCl 4 − has been reduced to Au 0 nanoparticles and deposited onto the surface of PGMA‐NH 2 . The current work shows a good prospect for PGMA‐NH 2 to be a valid adsorbent for the recovery of gold and the possible fabrication of gold nanoparticles by reduction–deposition process without any reductant.