Highly efficient electro-generation of hydrogen peroxide using NCNT/NF/CNT air diffusion electrode for electro-Fenton degradation of p-nitrophenol

Abstract

To promote the in situ generation of hydrogen peroxide (H2O2) in electro-Fenton system, a new air diffusion electrode (ADE) was put forward in the present work using N-doped multi-walled carbon nanotubes (NCNT) as the catalyst layer, multi-walled carbon nanotubes (CNT) as the diffusion layer, and nickel foam (NF) as the supporting material, respectively. The catalyst layer in ADE was characterized by transmission electron microscopy and X-ray photoelectron spectroscopy. Then the performances of H2O2 accumulation and p-nitrophenol (p-NP) degradation with the electrode (NCNT/NF/CNT ADE) were investigated. The experimental results showed that H2O2 accumulation on the NCNT/NF/CNT ADE was greatly improved by the presence of N doping, and H2O2 accumulation concentration could reach 307 mg L(-1) after 120 min at the current intensity of 100 mA. Moreover, the NCNT/NF/CNT ADE presented more effective performance on p-NP degradation than the CNT/NF/CNT ADE or the NF ADE. p-NP of initial 50 mg L(-1) could be almost completely removed after 30 min, and the total organic carbon removal efficiency reached 62.61% after 120 min when 0.4 mM Fe(2+) was added into the system. The repeatability test suggested that the stability of the NCNT/NF/CNT ADE was very good.

Towards the scale up of a pressurized-jet microfluidic flow-through reactor for cost-effective electro-generation of H2O2

“…Another key aspect of H2O2 electrolysers is the manner in which oxygen is supplied to the electrolyzer, given the low solubility of oxygen in water under room conditions (Scialdone et al, 2015;Tang et al, 2016). The simplest aeration system, bubbling oxygen/air into the solution, suffers from important oxygen transfer limitations.…”

Graphene-Modified Composites and Electrodes and Their Potential Applications in the Electro-Fenton Process

“…Gas diffusion electrodes (GDE) are being used increasingly in fuel cells [91], batteries [92,93] and in the generation of H 2 O 2 [94,95]. They are attractive in E-Fenton, as the solubility of dissolved oxygen is very low in water and, by using these GDE electrodes, the oxygen in air could be employed instead.…”