Adsorption of Au(III), Pd(II), and Pt(IV) from Aqueous Solution onto Graphene Oxide

Abstract

Graphene oxide (GO) was prepared and characterized by Fourier transform infrared spectrometry (FT-IR) and scanning electron micrographs (SEM). Batch adsorption studies were carried out to investigate the adsorption data, including the effects of pH, initial concentration, contact time, and temperature. The adsorption of Au(III), Pd(II), and Pt(IV) was optimum at pH 6.0. The adsorption isotherms all obeyed the Langmuir equation in the case of Au(III), Pd(II), and Pt(IV), and the maximum adsorption capacities were 108.342 mg•g −1 , 80.775 mg•g −1 , and 71.378 mg•g −1 , respectively. The adsorption kinetics of Au(III), Pd(II), and Pt(IV) onto GO followed a pseudosecond-order kinetic model, indicating that the chemical adsorption was the rate-limiting step. Thermodynamic parameters such as Gibbs energy (ΔG o ), enthalpy (ΔH o ), and entropy (ΔS o ) were calculated, indicating that the adsorption were spontaneous, endothermic, and feasible. The desorption studies showed that the best desorption reagents were 0.5 mol•dm −3 thiourea−0.5 mol•dm −3 HCl for Au(III) and 1.0 mol•dm −3 thiourea−0.5 mol•dm −3 HCl for both Pd(II) and Pt(IV).

CC Bonding of Graphene Oxide on 4‐Aminophenyl Modified Gold Electrodes towards Simultaneous Detection of Heavy Metal Ions

“…The current became very noisy when pH was higher than 7.0. The observation is consistent with the maximum adsorption capacity of GO towards Pb 2 + at pH 6.8 (328 mg/g) [31]. Au-Ph-GO sensing interface also provided highest sensitivity to Cu 2 + and Hg 2 + at pH 6.8.…”

“…The detection limits of three metals ions based on Au-Ph-GO sensing interface are comparable to those observed on the Au-cysteine-GO sensing interface (0.4 ppb for Pb 2 + , 1.2 ppb for Cu 2 + , and 0.8 ppb for Hg 2 + ) [22]. The adsorption ability of GO between different ions is different (under optimized conditions Q 1 for Pb 2 + , Cu 2 + , and Hg 2 + is 328 mg/g [32], 20 mg/g [31], and 270 mg/g [22], respectively), which results in the difference in sensitivity between different cations. For comparison, the calibration plots of OSWV peak current for detection of Pb 2 + , Cu 2 + , and Hg 2 + by using Au-Ph-NH-CO-GO sensing interface were also studied ( Figure S2 Supporting Inforamtion).…”

“…It shows that the OSWV current increased linearly in certain concentration range for each ion until the saturated value was reached. This adsorption behavior obeys Langmuir isotherm adsorption relation [29][30][31]:…”

Pore structure control factors of polyamine-bridged polysilsesquioxanes by sol–gel method and their structure-adsorption properties for Au(III)

“…As expected, adsorption capacity of C-DETA is much higher than other materials [18,22–35], implying its great potential in noble metal enrichment. …”

Preparation of L-Arginine-Modified Silica-Coated Magnetite Nanoparticles for Au(III) Adsorption

“…Desorption of precious metals by using a thiourea solution, HCl, thiourea-HCl, HNO 3 , thiourea-HNO 3 has been reported by previous researchers 22,26,30,54,55 . In this work, desorption of Au(III) adsorbed on Fe 3 O 4 /SiO 2 -GPTMS-Arg 1:2 (25.068 mg/g) was carried out within the different composition of eluent at a room temperature as presented in Table 7.…”