A facile template free solution approach for the synthesis of dypingite nanowires and subsequent decomposition to nanoporous MgO nanowires with excellent arsenate adsorption properties

Abstract

In this paper, one-dimensional (1-D) dypingite (hydrated magnesium carbonate hydroxide, Mg₅(CO₃)₄(OH)₂·5H₂O) nanowires with several hundreds micrometers in length were synthesized at 100 °C by a simple solution method without using any template or catalyst for the first time. A plausible diffusion growth model for the growth of the dypingite nanowires was proposed. The influences of the magnesium ion concentrations and the magnesium sources on the structures of the products were also studied. The as-synthesized nanowires were an excellent precursor for the fabrication of 1-D nanoporous magnesium oxide (MgO) nanowires via a simple thermal transformation process. Room temperature photoluminescence studies suggest that the nanoporous MgO nanowires show a strong ultraviolet emission and a weak blue emission. The adsorption properties of the porous MgO nanowires were investigated for As(V) removal. A high As(V) adsorption capacity of 384.6 mg g⁻¹ was realized, which was resulted from the reaction between the As(V) species and MgO in aqueous solution.