A kinetic model based on nonlinear regression analysis is proposed for the degradation of phenol under UV​/solar light using nitrogen doped TiO2

摘要

Nitrogen was doped into the TiO2 matrix in the concn. range of 0.05-​0.20 at.​% and the photocatalytic activities were tested for the degrdn. of phenol (Ph) under UV​/solar light using hydrogen peroxide (HP) and ammonium persulfate (APS) as electron acceptors. The prepd. photocatalysts characterized by various anal. techniques confirm the incorporation of nitrogen in the TiO2 lattice. The 0.15 at.​% dopant concn. shows higher photocatalytic activity compared with sol-​gel TiO2 (SG) and Degauss P25 TiO2 (P25) for the degrdn. process. Photoluminescence technique was used for studying the extent of hydroxyl radicals produced on TiO2 and TiO2-​xNx (NT) surface in the presence of oxidants under UV​/solar light irradn. The kinetic rate equation obtained for the best system TiO2-​xNx (x = 0.15 at.​%)​/APS​/under solar irradn. is found to be: r ap,​solar = 0.0041[NT]​0.54[APS]​0.71[Ph]​-​0.70. A kinetic​/math. model was developed based on the nonlinear regression anal. for the various processes and the validity of the model was tested by comparing the exptl. values with the theor. calcd. data as a function of variable parameters like catalyst dosage, concn. of electron acceptors and initial concn. of Ph.