Molecular adsorption model for organic compounds over TiO2 – P25 by protonic distribution affinity

Abstract

A  predictive  molecular  adsorption  model  for  organic  compounds  over  TiO2-P25  particles  was  formulated.  The  model is an extension of a theoretical method of surface characterization called Protonic Distribution Affinity (PDA),  which  is  obtained  from  potentiometric  titration  analysis,  zero  point  charge  (ZPC)  of  the  material  and adsorption isotherms of the Langmuir-Hinshelwood type. The chemical nature of the compound in the model was established by initial pH and molecular weigh.  We found that, for the TiO2-P25, the ZPC was 6.8. The model was validated using experimental data of dichloroacetic acid (DCA), 4-chlorophenol (4-CP) and phenol (PH) to different conditions. The model has high predictive capacity, numerical stability and sturdiness for obtaining the solutions. For available experimental data, the correlation coefficient was 0.97.