Study on morphology and degradation performance of alachlor on TiO2 nanotube photoelectrodes prepared under different conditions

TiO₂ nanotube array (TNTA) photoelectrodes were fabricated by anodization method on titanium (Ti) foil. The effects of voltage, electrolyte concentration and anodization time on the morphology and crystal structure were studied. The photocatalytic (PC) and photoelectrocatalytic (PEC) activity of TNTA was evaluated by the degradation rate of alachlor in aqueous solution. The results showed that the well-aligned TNTA, whose size of nanotube was 75~90nm, could be obtained at 20 V, 0.5%NaF+1mol/L Na₂SO₄ solution after one to three hours. The TNTA photoelectrodes annealed at 823K and 120 minutes exhibited high PC activity. The applied potential has obvious effect on the degradation rate of alachlor, which arrived to 94% after 120 minutes illumination with 1.5v bias potential.