β-FeOOH self-supporting electrode for efficient electrochemical anodic oxidation process.

Area of Science:

• Materials Science
• Environmental Chemistry
• Electrochemistry

Background:

• Wastewater treatment requires effective methods for degrading persistent organic pollutants like methyl orange (MO).
• Developing robust and reusable electrode materials is crucial for electrochemical oxidation processes.

Purpose of the Study:

• To synthesize a self-supporting β-FeOOH electrode using a facile hydrothermal method assisted by dopamine (PDA).
• To investigate the electrochemical anodic oxidation performance of the β-FeOOH electrode for methyl orange (MO) degradation.
• To explore the influence of key parameters (current density, pH, MO concentration) on MO degradation efficiency and understand the degradation mechanism.

Main Methods:

• Synthesis of β-FeOOH on carbon paper using a hydrothermal method with dopamine assistance.
• Electrochemical anodic oxidation experiments using the synthesized β-FeOOH electrode in MO solutions.
• Optimization of experimental conditions including current density, initial pH, and initial MO concentration.
• Analysis of MO degradation products using UV-vis and HPLC-MS.

Main Results:

• Achieved 99.4% MO degradation rate within 25 minutes under optimized conditions (10 mA cm⁻², pH 3, 10 mg L⁻¹ MO).
• Determined a pseudo-first-order reaction kinetic constant of 11.3 × 10⁻² min⁻¹ for MO degradation.
• Obtained a COD removal ratio of 37.3% after 120 minutes of electrolysis.
• Demonstrated high cycling stability with 84.9% MO removal after eight cycles.
• Showed efficient decomposition of multiple simulated pollutants, indicating broad applicability.

Conclusions:

• The synthesized β-FeOOH self-supporting electrode is highly effective for the electrochemical oxidation and degradation of methyl orange.
• The electrode exhibits excellent stability and potential for practical applications in treating industrial wastewater containing organic pollutants.
• The study provides insights into the degradation mechanism of MO via electrochemical anodic oxidation using the β-FeOOH electrode.