Hierarchical mesoscale assembly of PbO2on 3D titanium felt/TiO2nanotubular array electrode for anodic decolourisation of RB-5 dye

Abstract Hierarchical PbO 2 nanoparticles (NPs) were grown by hydrothermal method on TiO 2 nanotubes (NTs) at 3D titanium felt, which is simple and scalable method. TiO 2 NTs were formed on titanium felt by anodising at 25 °C in environmentally friendly methanesulphonic acid solution. The growth of PbO 2 on the TiO 2 NTs depended on immersion time during hydrothermal synthesis and followed a LaMer-Dinegar burst kinetic model of nucleation and growth. PbO 2 formation began with rapid nucleation, followed by mesoscale assembly due to organic capping of poly(vinylpyrrolidinone). The electrochemical performance of 3D electrode was recorded in pH 3 sodium sulphate solutions containing Reactive Black 5 (RB-5) azo dye at 25 °C. The resulting hierarchical 3D electrode achieved 98% decolourisation after 50 min of anodic oxidation with a first order batch decay rate of 0.0875 min −1 .