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

作者：Fu-Chun Wang; Jun-Mei Zhao; Wan-Kun Wang; Zi-Zheng Tong

来源：Rare Metals, 2018, 37(03): 196-203.

Monodispersed poly(glycidyl methacrylate)(PGMA) microspheres with various amounts of amino groups(PGMA-NH2) 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), thermogravimetrydifferential scanning calorimetry(TG-DSC), scanning electron microscopy-energy dispersive spectroscopy(SEM-EDS), transmission electron microscopy(TEM) and Fourier transform infrared spectroscopy(FTIR) confirms that AuCl4-has been reduced to Au0 nanoparticles and deposited onto the surface of PGMA-NH2. The current work shows a good prospect for PGMA-NH2 to be a valid adsorbent for the recovery of gold and the possible fabrication of gold nanoparticles by reduction-deposition process without any reductant.