Ti/SnO2-Sb2O5 Anode for Wastewater Treatment

May 19, 2021

Ti/SnO2-Sb2O5 Anode for Wastewater Treatment

Antimony-doped tin oxide (ATO) coated on titanium is one of the most studied anode materials for wastewater treatment. Denoted as Ti/SnO2-Sb2O5, this anode material is an inactive DSA-type of electrode material, so the oxygen evolution reaction can be suppressed to allow the degradation of organic compounds by hydroxyl radicals. Antimony-doped tin oxide is more efficient in the oxidation of organics than other DSAs with noble metals. Although the efficiency is not as high as that on BDD, there are several advantages over the latter material. ATO can be easily and economically coated on a Ti substrate, so it can be made into large areas for industrial applications.

The efficiency of ATO ranks higher than many of the active materials in mechanism. In comparison to other similar “inactive” materials such as PbO2 and boron-doped diamond (BDD), this anode material has distinct advantages.

Compared these three anode materials (ATO, PbO2 and BDD) in the oxidation of phenolic compounds and found ATO had a slightly higher current efficiency than PbO2 but significantly lower current efficiency than boron-doped diamond. The efficiency of BDD to be more than twice that of ATO, in the electro-oxidation of a range of dye compounds. Compared BDD and ATO and found that BDD had higher kinetic rates than ATO, but with modification, ATO could achieve an even faster degradation rate than BDD.

However, the service life of the Ti/SnO2-Sb2O5 anode material is quite short comparing with DSA anodes. The average life time in sulfuric acid ranged from less than 1 hour up to 15 hours.