Boosted Photocatalytic Activities of Ag 2 CrO 4 through Eu 3+ -Doping Process.

Ag ₂ CrO ₄ is a representative member of a family of Ag-containing 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 : x Eu 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.
Competing Interests: The authors declare no competing financial interest.
(© 2024 The Authors. Published by American Chemical Society.)