How competitive species such as buffer solutions influence the adsorption of dyes onto photocatalyst TiO2 particles

arious titanium based materials were chosen to obtain series of solids with various properties (structure, texture, morphology, surface reactivity...): nanopowder P25 and commercial Anatase; ElectroSpun nanofibres; trititanate nanotubes and mixed-phase anatase/trititanate. The adsorption of Rhodamine 6G was studied at natural pH and from phosphate buffer 0.1 M at different pHs. The adsorption capacities were dependent of the type of particles and the nature and pH of the solutions. Anatase and ES nanofibres had the lowest and the highest adsorption capacity respectively, with lower sorption at pH 6 due to the negative surface charge. This effect was rather small in the case of Anatase, which exhibits huge phosphate species adsorption. This demonstrates the competition between anionic species, and its consequence on the affinity for Rhodamine 6G in the presence of PO43-. (C) 2017 Elsevier Ltd. All rights reserved.