Kinetic investigation of photo-catalytic activity of TiO2/metal nanocomposite in phenol photo-degradation using Monte Carlo simulation

Abstract

Kinetic Monte Carlo simulation was applied to study the kinetics and photo-catalytic activity mechanism of TiO₂ anatase, P25, Au/TiO₂, Pd/TiO₂ and Au–Pd/TiO₂ applied in photo-degradation of water pollutants including phenol. The reaction kinetic mechanisms of each aforementioned catalytic system have been obtained. The values of the rate constant for each step of the reaction mechanisms were gained as adjustable parameters by kinetic Monte Carlo simulation. It was shown that the rate constant of formation of electron/hole pairs in metal loaded on titanium dioxide is greater than that of undoped TiO₂ because of electron transmission from titanium dioxide to the metal core. The kinetic study of metal performance in M/TiO₂ nano composites has demonstrated that the rate constant value of electron transfer from TiO₂ to Au is higher than that of Pd and Au–Pd. In this research the kinetic Monte Carlo simulation results agree qualitatively with the existing experimental data for phenol photo-decomposition.