Green fabrication of SH-modified GO composite for heavy metal ions removal in aqueous solution

摘要

Humic acid (HA) sodium salt (SH)-modified graphene oxide (GO) composite, which could snatch Pb (II), Cd (II) and Cu (II) effectively from aqueous solution, was fabricated by a green hydrothermal method. Here, the morphology and structure of as-synthesised SH-GO composite was presented through scanning electron microscopy, Roman spectra, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy and thermal gravimetric analysis. Owing to the introduction of cheap and readily available HA sodium salt, the adsorption capacity of SH-GO toward heavy metals was improved obviously, and the corresponding removal behaviours were further investigated in detail. Besides, the adsorption results were in good agreement with Langmuir isotherm and the pseudo-second kinetic model, where the thermodynamic parameters revealed the adsorption process was spontaneous and endothermic in essence. Adsorption-desorption result showing its stable adsorption capacity confirmed its great potential as adsorbent for removal of heavy metal ions from aqueous solution.