Surface Hydroxyl‐Assisted BiOBr Nanostructure Evolution for Remarkable Visible Light Photocatalytic Capability

Herein, various BiOBr nanostructures are successfully synthesized using a facile solvothermal method. A series of structural and morphological analyses clearly indicate that due to the nucleation protection provided by KOH and the presence of surface‐absorbed hydroxyl groups, BiOBr transforms from nanosheet microspheres to nanopillow aggregations (BNP) and finally to nanoneedle matrix. The open‐porous nanostructure of the BiOBr nanopillows (BNPs), along with their enhanced visible light absorption capacity and the presence of surface hydroxyls, enables them to adsorb nearly 100% of organic dyes, including rhodamine B (RhB), methylene blue, and methyl red. Furthermore, the BNP exhibits remarkable visible light photocatalytic activity, degrading higher concentrations of RhB in ≈20 min.