Engineering Stable Cu-Doped SrTiO₃ Perovskites for Enhanced Photocatalytic CO₂ Reduction

Area of Science:

• Materials Science
• Chemical Engineering
• Environmental Science

Background:

• Photocatalytic carbon dioxide (CO2) reduction is a promising sustainable energy technology.
• Strontium titanate (SrTiO3) is an efficient wide-bandgap semiconductor photocatalyst for CO2 reduction.
• Optimizing photocatalyst performance requires understanding reaction parameter influences.

Purpose of the Study:

• To investigate the effect of pH on the photocatalytic CO2 reduction efficiency and selectivity of copper-doped strontium titanate (Cu/STO).
• To synthesize and characterize Cu/STO using a hydrothermal method.
• To explore pH control as a strategy for enhancing photocatalyst stability and performance.

Main Methods:

• Hydrothermal synthesis of copper-doped strontium titanate (Cu/STO).
• Systematic variation of reaction pH using hydrochloric acid (HCl) and sodium hydroxide (NaOH).
• Analysis of product selectivity (methane and carbon monoxide) and photocatalyst structural stability under different pH conditions.

Main Results:

• pH significantly influences product selectivity, shifting the reaction pathway from methane (CH4) to carbon monoxide (CO) production.
• The 2Cu/STO photocatalyst exhibited excellent structural stability across all tested pH values.
• Cu/STO maintained a stable morphology under neutral (uncontrolled) pH conditions.

Conclusions:

• pH control is a critical factor in optimizing the selectivity and efficiency of photocatalytic CO2 reduction using Cu/STO.
• The introduction of pH modifiers can lead to undesired side reactions, impacting selectivity.
• This study demonstrates a novel strategy for designing stable, high-performance photocatalysts for sustainable energy applications.