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 center dot 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 center dot OH. This study may provide a feasible option to design of efficient electrodes for electrocatalytic degradation of organic pollutants.