Construction of TiO2 nanotube clusters on Ti mesh for immobilizing Sb-SnO2 to boost electrocatalytic phenol degradation

An efficient Sb-doped SnO₂ electrode featuring superior electrocatalytic characteristic and long stability was constructed by adopting clustered TiO₂ nanotubes-covered Ti mesh as substrate (M-TNTs-SnO₂). Compared with the electrodes prepared with mere Ti mesh or Ti plate grew with TiO₂ nanotube, the M-TNTs-SnO₂ exhibited higher TOC removal (99.97 %) and mineralization current efficiency (44.0 %), and longer accelerated service lifetime of 105 h for electrochemical degradation of phenol. The enhanced performance was mainly ascribed to the introduction of mutually self-supported TiO₂ nanotube clusters in different orientations. Such unique structure not only favored a compact and smooth surface of catalyst layer which improved the stability of electrode by reinforcing the binding force between substrate and catalyst layer, but also increased the loading capacity for catalysts, leading to 1.5-2.2 times higher of ·OH generation, the main active species for indirect electrochemical oxidation of phenol. Meanwhile, the transverse electron transfer from TiO₂ nanotube to catalyst layer was possibly achieved to further prompt the generation of ·OH. This study may provide a feasible option to design of efficient electrodes for electrocatalytic degradation of organic pollutants.