A three-dimensional gas diffusion electrode without external aeration for producing H2O2 and eliminating amoxicillin using electro-Fenton process

An Electrode with Two‐Level Porosity for Electro‐Fenton: Carbon Nanofiber‐Functionalized Macroporous Nickel Foam

“…In comparison to other carbon-coated Ni foams reported in the literature (Table S1, Supporting Information), e.g., biochar, [35] carbon black, [16] and N-doped carbons, [36] the CNF/ Ni foams represent higher CE values and a comparable H 2 O 2 production rate (2.2 mg h −1 cm −2 ) at a significantly lower average current density of 2.4 mA cm −2 . The highest value of 5.9 mg h −1 cm −2 was achieved by a Biochar/Ni foam at a current density of 10 mA cm −2 .…”

“…[35] Nevertheless, reported carbon-coated Ni foams were fabricated through a rolling technique, using powered carbon and PTFE as a binder, where a thin layer of carbon is deposited on the 3D structure of the foam. [16,35,36] Such deposition methods may completely cover the Ni surface, minimizing its contribution to the H 2 O 2 formation via oneelectron transfer or the chemical pathway. Furthermore, the presence of PTFE may block the porosity of powdered carbons, exacerbating the mass transport toward and away from the electrode surface and decreasing the active sites of carbon.…”

“…[12,13] Additionally, most activated carbon materials are powdery and need to be mixed with a polymeric binder, e.g., Polytetrafluoroethylene (PTFE), to be processed into an electrode assembly. [14][15][16] These fluorinated compounds, which are applied as binders, may not only block active sites of carbon but also increase the risk of secondary pollution by their undesired release from the electrode surface. [10,17] Furthermore, the regeneration of Fe 2+ on carbon electrodes is relatively slow at an applied potential suitable for two-electron oxygen reduction reaction (ORR), resulting in Carbon is an established electrode material in electrochemical reactors, e.g., for the generation of hydrogen peroxide (H 2 O 2 ).…”