Fabrication of high-performance 3D Porous SnO ₂ -Sb electrode modified with TiO ₂ -NTs and investigation on its electrocatalytic phenol degradation behavior

The widespread industrial application of SnO2-Sb anodes is impeded by the enduring trade-off between electrocatalytic activity and operational stability, mainly due to interfacial passivation and active-layer delamination. To address these limitations, we report a 3D hierarchical Ti foam/TiO2-NTs/SnO2-Sb electrode fabricated via in situ anodic oxidation followed by sol–gel deposition. Vertically aligned TiO2 nanotubes grown directly on the macroporous Ti foam provide a nano-confining, superhydrophilic interlayer that promotes deep wetting of precursor solutions and uniform anchoring of SnO2-Sb nanoparticles. This nanotubular interface reduces charge-transfer resistance, raises the oxygen evolution potential to 2.20 V (vs. SCE), and suppresses parasitic oxygen evolution, thereby improving current efficiency. In phenol degradation, the composite electrode delivers faster kinetics and higher mineralization efficiency than conventional Ti/SnO2-Sb. Accelerated life tests further reveal a markedly prolonged service life, attributed to the ‘riveting’ effect of the nanotubes, which mitigates thermal stress and restrains passivation-layer growth. These findings highlight a scalable strategy for constructing durable, high-performance porous anodes suited for industrial electrochemical wastewater treatment.