Electrogeneration of hydrogen peroxide on a novel highly effective acetylene black-PTFE cathode with PTFE film

Enhancement of H2O2 production and AYR degradation using a synergetic effect of photo-electrocatalysis for carbon nanotube/g-C3N4 electrodes

In this work, a new gas diffusion electrode (GDE) of carbon nanotube/graphitic carbon nitride (CNT/g-C₃N₄) was prepared, which enables the substantially improved production of H₂O₂ (up to 1083.54 mg L⁻¹) compared to generation without g-C₃N₄ (400 mg L⁻¹).

Dramatic enhancement of organics degradation and electricity generation via strengthening superoxide radical by using a novel 3D AQS/PPy-GF cathode

A dramatic enhancement of organics degradation and electricity generation has been achieved in a wastewater fuel cell (WFC) system via strengthening superoxide radical with radical chain reaction by using a novel 3D anthraquinone/polypyrrole modified graphite felt (AQS/PPy-GF) cathode. The AQS/PPy-GF was synthesized by one-pot electrochemical polymerization method and used to in-situ generate superoxide radical by reducing oxygen under self-imposed electric field. Results showed that methyl orange (MO) were effectively degraded in AQS/PPy-GF/Fe²⁺ system with a high apparent rate constant (0.0677 min^-1), which was 3.9 times that (0.0174 min^-1) in the Pt/Fe²⁺ system and even 9.4 times that (0.0072 min^-1) in the traditional WFC system (without Fe²⁺). Meanwhile, it showed a superior performance for electricity generation and the maximum power density output (1.130 mW cm^-2) was nearly 3.3 times and 5.0 times higher, respectively, when compared with the Pt/Fe²⁺ system and traditional WFC. This dramatic advance was attributed to 3D AQS/PPy-GF cathode which produces more O₂^- via one-electron reduction process. The presence of O₂^- cannot only directly contribute to MO degradation, but also promotes the final complete mineralization by turning itself to OH. Additionally, O₂^- accelerates the Fe²⁺/Fe³⁺ couple cycling, thus avoiding continuous addition of any external ferrous ions. Inhibition and probe studies were conducted to ascertain the role of several radicals (OH and O₂^-) on the MO degradation. Superoxide radicals were considered as the primary reactive oxidants, and the degradation mechanism of MO was proposed. The proposed WFC system provides a more economical and efficient way for energy recovery and wastewater treatment.

Electrocatalytic properties of N-doped graphite felt in electro-Fenton process and degradation mechanism of levofloxacin

The degradation of antibiotic levofloxacin was investigated by dimensionally stable anode as well as modified cathode using low-cost chemical reagents of hydrazine hydrate and ethanol for electro-Fenton in an undivided cell at pH 3.0 under room temperature. Comparison of unmodified and modified cathode was performed. The apparent rate constant of levofloxacin decay was found to be 0.2883 min^-1 for graphite felt-10 with the best performance at 200 mA, which is lower than graphite felt at 400 mA. The optimum modified cathode showed a significant improvement of complete mineralization of levofloxacin, reaching a 92% TOC removal at 200 mA for 480 min higher than unmodified one at twice the current. Surface physicochemical properties and morphology were investigated by scanning electron microscope, contact angle and X-ray photoelectron spectroscopy. The electrochemical characterization of hydrogen evolution reaction was adopted to clarify a possible pathway for the higher mineralization of levofloxacin, indicating a potential pilot-scale study to the pollution with the similar structure.

In situ electrosynthesis of hydrogen peroxide with an improved gas diffusion cathode by rolling carbon black and PTFE

A simply structured gas diffusion electrode (GDE) was constructed by rolling carbon black and PTFE as a conductive catalyst layer to enhance the producibility of hydrogen peroxide.