Rubidium Doped Cs₂AgBiBr₆ Hierarchical Microsphere for Enhanced Photocatalytic CO₂ Reduction

Area of Science:

• Materials Science
• Photocatalysis
• Renewable Energy

Background:

• Halide perovskites show promise for solar-to-fuel applications due to their optoelectronic properties.
• Current halide perovskite photocatalysts for CO2 reduction suffer from charge recombination and insufficient active sites.

Purpose of the Study:

• To develop a rubidium (Rb)-doped Cs2AgBiBr6 (Rb:CABB) hierarchical microsphere for enhanced photocatalytic CO2 reduction.
• To investigate the effect of Rb doping on the electronic structure and active sites of Cs2AgBiBr6.

Main Methods:

• Synthesis of Rb-doped Cs2AgBiBr6 hierarchical microspheres.
• Experimental characterization and theoretical analysis of the material's electronic structure and catalytic activity.
• Evaluation of photocatalytic CO2 reduction efficiency, focusing on CO yield.

Main Results:

• Rb doping effectively modulated the electronic structure of Cs2AgBiBr6, promoting charge separation.
• Rb+ substitution for Ag+ created electron-rich Bi active sites and reduced energy barriers for CO2 reduction.
• Rb:CABB demonstrated a significantly enhanced CO yield compared to undoped Cs2AgBiBr6.

Conclusions:

• Rb doping is a viable strategy to optimize halide perovskite photocatalysts for CO2 reduction.
• This work offers a new pathway for designing efficient halide perovskite-based materials for solar-to-fuel conversion.