Design of micro-nano spherical β-NiOOH/FeMoO4 composite with enhanced photo-Fenton performance.

In this work, micro-spherical β-NiOOH/FeMoO 4 with multiple active sites was prepared by one-step solvothermal method and its performance in the photo-Fenton system was investigated. The results indicate that highest degradation efficiency of methylene blue (MB) was obtained when the molar ratio of nickel to iron was 1:2.5. In addition, composites were assessed for its degradation performance for MB by adjusting the concentration of H 2 O 2 , pH and catalyst dosage. The pseudo-first-order kinetic rate constant of MB degradation in β-NiOOH/FeMoO 4 catalyzed photo-Fenton system was 0.234 min−1 about 5 folds that of pristine FeMoO 4 micro-sphere. The degradation mechanism of MB was deduced by active species quenching experiments and technology of coumarin fluorescent probe. And its degradation pathway was proposed by LC-MS identifying reaction intermediates produced during photo-Fenton catalysis. Recycling tests have confirmed excellent stability of β-NiOOH/FeMoO 4 composite. In conclusion, this study demonstrates the β-NiOOH/FeMoO 4 composite is a promising heterogeneous photo-Fenton catalyst. [Display omitted] • Microspheres with special particle accumulation surface structure were prepared. • The doped of Fe enables NiOOH to crystallize stable into β phase. • The degradation efficiency of MB can reach 99.5% in 18 min. • The generation potential of ·OH was indirectly determined by the coumarin fluorescence probing technique. [ABSTRACT FROM AUTHOR]