One-pot synthesis of a ceria–graphene oxide composite for the efficient removal of arsenic species

Abstract

Arsenic contamination has posed a health risk to millions of people around the world. In this study, we describe a simple and facile one-step hydrothermal synthesis of a ceria-graphene oxide (ceria-GO) composite for the efficient removal of arsenic species. The prepared ceria-GO composite materials exhibited almost complete (over 99.99%) and quick removal of both arsenic species within 0.1 mg L^-1 of the initial concentration. The calculated adsorption capacities were 185 mg g^-1 for As(iii) and 212 mg g^-1 for As(v). It was found that Ce³⁺ is an active site and continuously adsorbs arsenic species; there is a concomitant change from Ce⁴⁺ to Ce³⁺ due to the solution redox environment. This increase in the Ce³⁺ concentration further facilitates the complete removal of arsenic species in solution. Thus our approach offers a promising potential for the treatment of arsenic-contaminated drinking water.