Photo-assisted Fenton reactions and growth evolution of crack-urchined CuBi2O4 microspheres assembled by nanorods

Abstract Hierarchical CuBi2O4 microspheres assembled by nanorods were prepared via a facile hydrothermal process. The nanorods were orderly grown along [001] crystal direction with rectangular cross-sections and a broad diameter distribution ranging of 100–350 nm. One narrow crack is distinct on the surfaces of each microsphere, which separates the microsphere into two approximately equal parts. Growth evolutions of as-prepared CuBi2O4 were fully discussed according to various reaction times. The microspheres were formed by radiated extension of nanorods which split along cleavage planes due to high internal stresses. The as-prepared CuBi2O4 exhibited a strong optical absorption in wavelength of 300–630 nm. Under visible light (λ ≥ 420 nm), an improved degradation efficiency of 89.6% to Rhodamine B (RhB) was determined with the aid of H2O2. The crack-urchined structures as well as the redox reactions between CuBi2O4 and H2O2 should be responsible for it.