Efficient generation of HO by novel magnesium-carbon nanotube composites.

Hydrogen peroxide (HO) is widely employed as an environmentally friendly chemical oxidant and an energy source. In this study, a novel magnesium-carbon nanotube composite was prepared by a ball milling process in argon atmosphere using polyvinylidene fluoride (PVDF) as a binder. The resulting material was then tested for the generation of HO. The preparation and operation conditions of the composite were systemically investigated and analyzed to improve the efficiency of the generation of HO. Under the optimized conditions, while aerating with oxygen for 60 min, a maximum HO concentration of 194.73 mg L was achieved by the Mg-CNTs composite prepared using Mg : CNT : PVDF with a weight ratio of 5 : 1 : 2.4. In the Mg-CNTs/O system, dissolved oxygen molecules were reduced to HO, while magnesium was oxidized owing to the electrochemical corrosion. In addition, a part of dissolved magnesium ions converted into magnesium hydroxide and precipitated as nanoflakes on the surfaces of CNTs. A mechanism was proposed, suggesting that the formation of a magnesium/carbon nanotubes corrosion cell on the Mg-CNT composite promoted the synthesis of HO. Overall, this study provides a promising and environmentally friendly strategy to fabricate magnesium/CNT composites for the generation of HO, which could be applied in energy conversion and advanced oxidation processes for refractory wastewater treatment.