Green synthesis of graphene oxide from oil palm leaves as novel adsorbent for removal of Cu(II) ions from synthetic wastewater

Abstract

A graphene oxide (GO) sheet was synthesized via a catalytic acid spray (CAS) method in the presence of Co silicate as catalyst. The newly developed GO was characterized using FTIR, HRTEM, XRD and TGA. The performance of the GO for Cu ions adsorption was carried out through batch studies as a function of pH, adsorbent dose, temperature and initial Cu ions concentrations. FTIR shows that GO is comprised of some efficient hydroxyl (OH), epoxy (cyclic ether), carboxyl (COO) and carbonyl (CO) groups. XRD analysis shows that interlayer spacing of the prepared GO was to some extent higher than that of other GO produced by other processes. It seems that GO synergistically interacts with Cu to form more stable complexes with heavy metals, and as a consequence, the GO can adsorb relatively a larger amount of heavy metals. The adsorption parameters, such as pH, adsorbent dose, contact time, initial metal ion concentration and temperature, were optimized.