Simulation Analysis of the Transient Absorption Spectroscopic Dynamics of Charge Recombination in a Semiconductor Attached with a Gold Nanoparticle Using Initially Variable Coordinates

Abstract

A Monte Carlo random walk (MCRW) was used to simulate the photocatalytic kinetics of electron diffusion and charge recombination in gold-titanium dioxide (Au/TiO\({}_{2}\)). We designed an MCRW algorithm using MATLAB for one-sided absorption and three-sided reflectance in a rectangle, which conformed to be a good model of photocatalyst nanoparticles (Au/TiO\({}_{2}\)) in ultrafast spectra reported. As the initial point coordinates change, the corresponding absorption histogram and probability density are obtained. From this simulation, we analyzed both the decay of electron particle absorption and the lifetime; namely, the closer the electrons are to the initial coordinates \(x=1\), the faster the corresponding decays are. By means of the fitting curve, we verified that electron diffusion strongly depends on the initial coordinates measured from the TiO\({}_{2}\) nanoparticle interfaces.