The Effects of Some Operational Parameters in Photodegradation of Benzylamine and Aniline and Their Kinetics in Aqueous Suspension of TiO₂ and Pt–Loaded TiO₂

Abstract

Photocatalytic degradation of benzylamine and aniline on TiO2, Pt-modified TiO2, ZnO and ZnS in aqueous solution has been investigated. The degradation of the compounds follows a pseudo-first-order kinetics according to Langmuir-Hinshelwood model. The degradation process of benzylamine and aniline was evaluated by ninhydrin spectrophotometric method using UV-visible spectrophotometer in lambda(max) = 538 and 525 nm, respectively. The results showed the order of Pt/TiO2 > TiO2 > ZnO > ZnS for photocatalytic activity. In addition increasing of the Pt-loading was found to enhance the degradation rate of the compounds up to the optimal amount of 5 wt. % onto the surface of TiO2 so that the rates of degradation were increased about two times. Rate constants for photodegradation of benzylamine and aniline were found to be 1.4 x 10(-3) min(-1) and 0.7 x 10(-3) min(-1) for TiO2 as photocatalyst, while 2.7 x 10(-3) min(-1) and 1.7 x 10(-3) min(-1) for (5 wt.%) Pt/TiO2 as photocatalyst. Running the reactions in various pH (5-11), indicated that the pH = 8 and 10 or Higher are the optimum pH for photocatalytic degradation of benzylamine and aniline respectively. The effects of some other parameters such as amount of photocatalyst, flux of oxygen and irradiation time were evaluated. Furthermore, the Langmuir-Hinshelwood rate constant k(r) and adsorption constant K(A) for the titled compounds are reported.

Photocatalytic degradation of an organic dye in some aqueous buffer solutions using nano titanium dioxide. A kinetic study

“…Various reported researches on removal of this water pollutant [14][15][16][17][18] obviously reveal importance of subject. In continuation of our previous reports on photodegradation processes [19][20][21][22], in this work we report photocatalytic degradation of emerald green on nano titanium dioxide at aqueous buffer of pH 7, 8 and 9. The effect of some operating parameters and kinetics study of its photodegradation at each pH are described.…”

Kinetic Study of Photocatalytic Degradation of Tolonium Chloride Under High Pressure Irradiation in Aquatic Buffer Systems

“…Previously photocatalytic decomposition of tolonium chloride in the presence degussa-type titanium dioxide under medium pressure mercury lamp irradiation at non-bufferic system has been reported 16 . In continuation of our previous works [17][18][19][20] in this work kinetic study of photodegradation of tolonium chloride (also known as Toluidine Blue) in the presence of anatase titanium dioxide under high pressure mercury lamp at various buffer system is described and compared with previous reported conditions.…”