Light-Driven Fuel Cell with a 2D/3D Hierarchical CuS@MnS Z-Scheme Catalyst for H₂O₂ Generation

Area of Science:

• Materials Science
• Electrochemistry
• Environmental Science

Background:

• Conventional anthraquinone process for hydrogen peroxide (H₂O₂) production is energy-intensive.
• Photoelectrocatalytic (PEC) oxygen reduction reaction (ORR) offers a sustainable alternative for H₂O₂ synthesis.
• Development of efficient and cost-effective catalysts is crucial for PEC H₂O₂ production.

Purpose of the Study:

• To develop a novel two-dimensional (2D)/three-dimensional (3D) hierarchical CuS@MnS p-p Z-scheme catalyst for PEC H₂O₂ production.
• To investigate the catalyst's performance in a two-compartment cell for dual H₂O₂ production.
• To demonstrate a multifunctional PEC system for chemical synthesis, energy recovery, and pollutant degradation.

Main Methods:

• Fabrication of a 2D/3D hierarchical CuS@MnS p-p Z-scheme catalyst.
• Utilizing the catalyst as a photocathode for PEC synthesis of H₂O₂.
• Coupling the PEC system with Sn₃O₄/Ni foam in a two-compartment cell.
• Integration with a direct hydrazine/O₂ fuel cell for energy-saving H₂O₂ generation.
• Application in a cascade heterogeneous Fenton reaction for pollutant degradation.

Main Results:

• Achieved H₂O₂ yield of 1.65 mM within 180 min using the CuS@MnS photocathode.
• Demonstrated boosted activity and stability for dual H₂O₂ production in the coupled system.
• Showcased significant reduction in electricity consumption for H₂O₂ synthesis via the fuel cell integration.
• Accelerated pollutant degradation through onsite H₂O₂ generation and a cascade heterogeneous Fenton reaction.

Conclusions:

• The novel CuS@MnS catalyst enables efficient PEC synthesis of H₂O₂ with full spectrum absorption and strong coupling interface.
• The developed multifunctional PEC system offers a sustainable and energy-saving approach for H₂O₂ production.
• This strategy provides a pathway for designing advanced PEC systems for high-value chemical production, energy recovery, and environmental remediation.