Construction of a novel nitrogen- and oxygen-containing GO-based composite with specific adsorption selectivity

Abstract

A novel graphene oxide (GO)-based composite, which was covalently functionalized by 1,3-bis(tris(hydroxymethyl)methylamino)propane (BTP), was first fabricated. The adsorption properties of GO-BTP composite toward some inorganic ions including rare earth elements and heavy metal ions, as well as some organic substances such as phenols and dyes were investigated. It can be found that the adsorption capacities of GO-BTP composite for La3+, Er3+, Cu2+, Pb2+, tert-butyl hydroquinone (TBHQ), m-nitrophenol (MNP), p-nitrophenol (PNP), alizarin red S (ARS) and neutral red (NR) were 0, 0.6, 6.32, 16.25, 27.28, 80.88, 101.69, 54.4 and 101.32 mg g−1, respectively. The morphologies and the compositions of GO-BTP composite, as well as the adsorption mechanism, were investigated by scanning electron microscopy, specific surface area analysis by Brunauer–Emmett–Teller method, Fourier transform-infrared spectroscopy, thermal gravimetric analysis, zeta potential measurements and X-ray photoelectron spectroscopy, respectively. The results indicated that the removal rates of GO-BTP composite were around 90% for PNP and 98% for NR even after 10 cycles of sequential adsorption-desorption tests. The GO-BTP composite can be considered as a promising adsorbent in the efficient adsorption of organic substances and the effective separation of mixtures of inorganic and organic pollutants in aqueous solutions.