Boosting CO₂ Reduction with Spinel CoAl₂O₄ Anchored on N-Doped Graphitic Carbon

Area of Science:

• Materials Science
• Catalysis
• Environmental Science

Background:

• Efficient charge transfer and separation of photo-generated carriers are crucial for photocatalysis.
• Developing stable and active photocatalysts for CO2 reduction is essential for environmental remediation.

Purpose of the Study:

• To fabricate and investigate a novel CoAl2O4@nitrogen-doped graphitic carbon (CoAl2O4@NGC) composite photocatalyst.
• To evaluate its performance in photocatalytic CO2 reduction.

Main Methods:

• Stepwise hydrothermal method and high-temperature calcination for catalyst synthesis.
• Characterization using XRD, TEM, XPS, and photoelectrochemical measurements.
• Systematic investigation of photocatalytic performance for CO2 reduction.

Main Results:

• CoAl2O4 nanoparticles uniformly anchored on NGC substrate, forming a well-integrated interface.
• CoAl2O4@NGC exhibited excellent catalytic activity (CO: 27.88 μmol·g−1·h−1, CH4: 23.90 μmol·g−1·h−1) and cycling stability.
• Narrow bandgap (1.54 eV) enhanced visible light absorption, improving electron-hole separation and charge transfer.

Conclusions:

• The CoAl2O4@NGC composite demonstrates superior photocatalytic activity and stability for CO2 reduction.
• Synergistic effects between spinel CoAl2O4 and NGC enhance CO2 activation and conversion.
• This study provides valuable insights for designing efficient spinel/nitrogen-doped carbon composite photocatalysts.