The influence of micro-/macro-structure of a boron-doped diamond electrode on the degradation of azo dye Direct Red 80

•Comparison of BDD electrodes with different micro/macrostructural properties.•Removal of a hardly degradable azo dye with identification of degradation products.•Silicon structuring proved to be beneficial for the degradation of azo dyes.•3D arrangement of the electrode has a major influence on the dye removal rate.•Economic assessment- achieved energy consumption under 20 kWh per 1 kg of COD.