Key role of material pore size in development of porous TiOx electrodes for removal of organic compounds in flow-through reactor

Abstract

Different porous TiOx electrodes were synthesized for removing organic pollutants from water with a focus on the role of their porous structure on efficiency of electrocatalytic phenomena. In stirred-tank reactor, lower reaction rates were obtained using electrode with small pores (≈ 2.2 µm), while coarse roughness of electrodes with larger pores (≈ 100 µm) was beneficial. However, electrode with small pores allowed obtaining optimal mass transport in flow-through configuration. The reaction rate for degradation of 0.1 mM of terephthalic acid was 27 times higher compared to stirred-tank reactor. Reaction rates of electrodes with large pores were still limited from diffusion within pores and the reaction rate was divided by 2.8 at the optimal flux, compared to the electrode with small pores. A correlation was established between degradation yields, operating conditions and key characteristics of the porosity, which is crucial for the design of novel electrode materials with suitable porous structure.