Dual-function oxygen vacancy of BiOBr intensifies pollutant adsorption and molecular oxygen activation to remove tetracycline hydrochloride

•BiOBr nanospheres with oxygen vacancy is prepared via solvothermal method.•BiOBr-OV exhibits better TC removal performance by adsorption and degradation.•Oxygen vacancy enhances ion exchange adsorption due to the effective hydrolysis and dehydration.•Surface complex via adsorption promotes degradation by faster charge transfer.•Oxygen vacancy achieves an effective activation of molecular oxygen.