Chemical Engineering Journal, Vol.334, 206-215, 2018
A novel anode with anticorrosive coating for efficient degradation of toluene
The polydopamine (PDA) coating was used to modify the surface of the PbO2/TiO2 nanotube arrays (PTNAs) by impregnation method. The obtained PDA-PbO2/TiO2 nanotube arrays (PPTNAs) coating exhibited a sandwich structure and used as anode for photoelectrochemical degradation of toluene. Generally, due to the symmetric structure and conjugation of methyl with benzene ring, the degradation of toluene was difficult to carry on. Our results show that the rate of toluene degradation can reach up to 66% at the surface of PPTNAs coating anode, it is much higher than that of the TiO2 nanotube arrays coating anode, 17%. The reduction product at cathode, hydrogen, was also measured, which is one of the valuable source of energy. In the coupled effect of applied voltage and photocatalysis on the PPTNAs anode, the degradation of toluene was carried out smoothly. The introduction of lead dioxide nanoparticles on the coated anode possessed favorable electronic conductivity in strong acid, which is benefit for a high rate of electrons transportation at the interface of TiO2 and lead dioxide. The excellent corrosion resistance of PPTNAs coating further ensured the effective degradation of toluene with long-term stability. Meanwhile, the unique adhesion of the outer PDA coating increased the contact opportunities between toluene molecules and the anode surface, and enhanced the photocatalytic activity of the PPTNAs coating anode. The applied voltage suppressed the recombination of electron-hole pairs and provided abundant reaction sites. All of these increased the photo-electro catalysis of toluene degradation. The new fabricated anode material shows good prospective application of cleaning up refractory pollutants and the resource utilization.