Exploring Pt-Impregnated CdS/TiO₂ Heterostructures for CO₂ Photoreduction

Area of Science:

• Materials Science
• Photocatalysis
• Renewable Energy

Background:

• Carbon dioxide reduction is crucial for mitigating climate change.
• Photocatalytic conversion of CO2 to methane offers a sustainable energy pathway.
• Titanium dioxide (TiO2) based materials are widely studied for photocatalysis, but often suffer from low efficiency due to electron-hole recombination.

Purpose of the Study:

• To synthesize and characterize Pt-doped CdS/TiO2 heterostructures for enhanced photocatalytic CO2 reduction.
• To investigate the role of CdS and Pt nanoparticles in improving photocatalytic activity.
• To evaluate the methane production efficiency of the developed photocatalysts.

Main Methods:

• Solvothermal synthesis of CdS nanoparticles.
• Impregnation of Pt onto CdS/TiO2 heterostructures.
• Characterization using XRD, ICP-OES, SEM-EDX, TEM, XPS, UV-Vis, UPS, and PL spectroscopy.
• Photocatalytic reduction of CO2 to methane under simulated solar irradiation.

Main Results:

• Successful synthesis of Pt-doped CdS/TiO2 heterostructures.
• Characterization confirmed the formation and composition of the heterostructures.
• Pt and CdS nanoparticles effectively reduced electron-hole recombination by acting as electron sinks.
• The optimized Pt-doped CdS/TiO2 heterostructure exhibited significantly higher methane production (460 µmol CH4/g·h) compared to P25 TiO2 (397 µmol CH4/g·h).

Conclusions:

• Pt-doped CdS/TiO2 heterostructures are highly effective photocatalysts for CO2 conversion to methane.
• The enhanced efficiency is attributed to the reduced electron-hole recombination facilitated by CdS and Pt.
• This study presents a promising approach for sustainable methane production from carbon dioxide.