Removal of Arsenic (V) From Waste Water Using Highly Porous Fe-Doped Graphene Hydrogel
Graphene oxide (GO) is a two-dimensional structure of carbon atoms, and has recently been widely used in several applications because of its unique electrical, chemical and mechanical properties . In this study, a Fe-GO composite, separately prepared, was doped in the resorchinol-formaldehyde (RF) matrix to prepare the Fe-GO-RF composite by sol-gel polymerization. The wet gel was dried using freeze drying, instead of the commonly used supercritical CO2-drying. The GO suppressed the collapse of nanopores in the RF hydrogel during the drying process. The gel was carbonized at 1050 oC under N2 flow to synthesize the Fe-graphene hydrogel (Fe-GH). The synthesized materials were characterized using several analytical instruments, such as scanning electron microscopy, Fourier transform infrared spectroscopy, surface area and pore size distribution analysis and energy dispersive X-ray spectroscopy. The in-situ doped Fe metal in Fe-GH served as the crosslinker by assembling GO into the 3D porous RF gel, and also, as the polymerization catalyst, besides exhibiting an excellent binding affinity for arsenic(V).