Synthesis, structure, and characterization of RbNdGe2O6 as a novel visible-light-driven catalyst for photodegradation methylene blue.

A novel lanthanide germanate, namely RbNdGe 2 O 6 , has been successfully synthesized by high-temperature solid-state reaction in open air atmosphere for the first time. Single crystal X-ray diffraction indicates a 3D framework composed of 1D neodymium oxygen chains connected with cyclogermanate Ge 3 O 9 units with Rb+ located in the internal space. X-ray powder diffraction coupled with Rietveld refinement reveals the sample's phase purity we have prepared. Thermal behavior analysis shows RbNdGe 2 O 6 is very stable, it doesn't decomposition until heated up to 998 ​°C. UV–visible absorption and diffuse reflection spectrum feature characteristic absorption bands of f -electron transition and an optical bandgap value of 4.65 ​eV. Magnetic susceptibilities measurement gives significant antiferromagnetic interactions between magnetic centers. The photodegradation experiments were performed to evaluate photocatalytic activities of RbNdGe 2 O 6. By using P25 as a reference, RbNdGe 2 O 6 features to be an effective visible-light-driven catalyst in photodegrading methylene blue. Although the BET value of RbNdGe 2 O 6 is only 3% that of P25, the photocatalytic activity reaches 0.55 times that of P25. Furthermore, the proposed photocatalytic mechanism which dominated by holes was further verified by adding ammonium oxalate as a quencher. New compound RbNdGe 2 O 6 was reported for the first time. Its structure features a 3D framework composed of 1D neodymium oxygen chains connected with cyclogermanate Ge 3 O 9 units with Rb+ located in the internal space. This material features an impressive visible-light-driven photodegradation methylene blue, and the proposed photocatalytic mechanism was also studied. Image 1 [ABSTRACT FROM AUTHOR]