Hierarchical mesoscale assembly of PbO2 on 3D titanium felt/TiO2 nanotubular array electrode for anodic decolourisation of RB-5 dye

Abstract

Abstract Hierarchical PbO2 nanoparticles (NPs) were grown by hydrothermal method on TiO2 nanotubes (NTs) at 3D titanium felt, which is simple and scalable method. TiO2 NTs were formed on titanium felt by anodising at 25 °C in environmentally friendly methanesulphonic acid solution. The growth of PbO2 on the TiO2 NTs depended on immersion time during hydrothermal synthesis and followed a LaMer-Dinegar burst kinetic model of nucleation and growth. PbO2 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.