Boosted Photocatalytic Activities of Ag₂CrO₄ through Eu³⁺-Doping Process

Abstract

Ag 2 CrO 4 is a representative member of a family of Agcontaining semiconductors with highly efficient visible-light-driven responsive photocatalysts. The doping process with Eu 3+ is known to effectively tune their properties, thus opening opportunities for investigations and application. Here, we report the enhancement of the photocatalytic activity and stability of Ag 2 CrO 4 by introducing Eu 3+ cations. The structural, electronic, and photocatalytic properties of Ag 2 CrO 4 :xEu 3+ (x = 0, 0.25, 0.5, 1%) synthesized using the coprecipitation method were systematically discussed, and their photodegradation activity against rhodamine B (RhB), ciprofloxacin hydrochloride monohydrate (CIP), and 4-nitrophenol (4-NP) was evaluated. Structural analyses reveal a short-range symmetry breaking in the Ag 2 CrO 4 lattice after Eu 3+ doping, influencing the material morphology, size, and electronic properties. XPS analysis confirmed the incorporation of Eu 3+ and alteration of the surface oxygen species. Furthermore, photoluminescence measurements indicated that the doping process was responsible for reducing recombination processes. The sample doped with 0.25% Eu 3+ exhibited superior photocatalytic performance compared to pure Ag 2 CrO 4 . Scavenger experiments revealed an increase in the degradation via • OH reactive species for the sample doped with 0.25% Eu 3+ . DFT calculations provided atomic-scale insights into the structural and electronic changes induced by the Eu 3+ doping process in the Ag 2 CrO 4 host lattice. This study confirms that Eu 3+ doping alters the band structure, enabling different degradation paths and boosting the separation/transfer of photogenerated charges, thereby improving the overall photocatalytic performance.