Efficient in situ generation of H2O2 by novel magnesium–carbon nanotube composites

Abstract

Hydrogen peroxide (H₂O₂) 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 in situ generation of H₂O₂. The preparation and operation conditions of the composite were systemically investigated and analyzed to improve the efficiency of the in situ generation of H₂O₂. Under the optimized conditions, while aerating with oxygen for 60 min, a maximum H₂O₂ concentration of 194.73 mg L⁻¹ 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/O₂ system, dissolved oxygen molecules were reduced to H₂O₂, 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 in situ synthesis of H₂O₂. Overall, this study provides a promising and environmentally friendly strategy to fabricate magnesium/CNT composites for the in situ generation of H₂O₂, which could be applied in energy conversion and advanced oxidation processes for refractory wastewater treatment.