Cobalt-doped UiO-66 nanoparticle as a photo-assisted Fenton-like catalyst for the degradation of rhodamine B

Metal-organic frame materials are intensively investigated in catalysis due to their outstanding thermal stability, large specific surface area, and ultra-high porosity. In this work, a cobalt-doped zirconium-based metal-organic framework, Co-UiO-66, was synthesized by the hydrothermal approach. Co-UiO-66 could successfully activate peroxymonosulfate (PMS) ions to produce reactive oxygen species for the degradation of rhodamine B (RhB) when it was used as a Fenton-like catalyst. The catalyst with 4% Co in mass in UiO-66 (4% Co-UiO-66) showed the highest degradation efficiency. About 97.3% of RhB (50 ml of 30 mg L −1 ) was degraded in 45 min under simulated sunlight when 10 mg of 4% Co-UiO-66 was used. The degradation efficiency was much higher than that when pure UiO-66 was used. Furthermore, it was even slightly higher than when cobalt ions were used as the activator. The single-atomic dispersion and confinement effect in Co-UiO-66, as well as the strong absorption in the visible light region are responsible for the high catalytic efficiency. The combination of single-atom dispersion and confined nanoreactor can improve the degradation of RhB during the photo-assisted PMS activation catalysis process. • A single-atom Co-based catalyst was prepared by the hydrothermal method. • Single-atom dispersion and confined nanoreactor can improve the catalytic processes. • The 4% Co-UiO-66 displays an enhanced catalytic performance toward RhB degradation. • A reasonable Fenton-like catalytic mechanism for Co-doped UiO-66 is proposed.