Boosted Photocatalytic Activities of Ag₂CrO₄ through Eu³⁺-Doping Process

Area of Science:

• Materials Science
• Photocatalysis
• Semiconductor Chemistry

Background:

• Silver chromate (Ag₂CrO₄) is a semiconductor photocatalyst with visible-light-driven applications.
• Doping with rare-earth elements like Europium (Eu³⁺) can tune semiconductor properties for enhanced performance.

Purpose of the Study:

• To investigate the effect of Eu³⁺ doping on the structural, electronic, and photocatalytic properties of Ag₂CrO₄.
• To evaluate the photocatalytic degradation of organic pollutants using Eu³⁺-doped Ag₂CrO₄.
• To understand the mechanisms behind the enhanced photocatalytic activity.

Main Methods:

• Coprecipitation synthesis of Ag₂CrO₄:xEu³⁺ (x = 0–1%).
• Characterization using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and photoluminescence (PL).
• Photocatalytic activity testing against rhodamine B, ciprofloxacin hydrochloride, and 4-nitrophenol; scavenger experiments and DFT calculations.

Main Results:

• Eu³⁺ doping induced short-range symmetry breaking in the Ag₂CrO₄ lattice, altering morphology and electronic properties.
• XPS confirmed Eu³⁺ incorporation and changes in surface oxygen species.
• Photoluminescence indicated reduced charge recombination, with the 0.25% Eu³⁺ doped sample showing superior photocatalytic activity and increased ^•OH radical generation.
• DFT calculations revealed altered band structure and improved photogenerated charge separation/transfer.

Conclusions:

• Eu³⁺ doping significantly enhances the photocatalytic activity and stability of Ag₂CrO₄.
• The optimal doping concentration of 0.25% Eu³⁺ leads to improved degradation of organic pollutants.
• Eu³⁺ doping modifies the electronic structure and promotes charge carrier dynamics, making it a promising strategy for advanced photocatalyst design.