Stepwise blossoming of BiOBr nanoplate-assembled microflowers and their visible-light photocatalytic activities

Abstract

Stepwise blossoming of nanoplate-assembled BiOBr microflowers from bud to blossom structures with average diameters from 1 to 3.5 μm and nanoplate thicknesses from 25 to 120 nm is obtained in a solvothermal system through surfactant modulation and time control. The above BiOBr structures exhibit excellent visible-light photocatalytic activity toward degradation of methylene blue (MB) solution, among which the structure from a 24 h reaction gives the best photocatalytic activity. A quantitative relationship is established among crystallite size (R), specific surface area (S) and photocatalytic activity (D). The equation D = 15(R)^2/5(S)^1/5 offers a quantitative characterization of crystallinity-dominated photocatalytic activity.