Photocatalytic Reaction Dynamics and Mechanism of Layered Semiconductor Materials

The development of highly active and energy efficient novel nanostructured photocatalysts is important in the field of photocatalysis science. Recently, some layered semiconductor materials such as graphite-like C3N4 and graphite oxides demonstrated tremendous potential in this regard due to their novel electronic structures. Their photocatalytic reaction dynamics and mechanisms as well as performance improvements require further extensive studies. Our present proposal will focus on electronic properties of layered semiconductor materials including graphite-like C3N4 and graphite oxides and effects of their structure modulations on photocatalytic reactivity by performing molecular level theoretical studies. By selective doping and/or surface functionalization, we modify and design the materials’ geometric and electronic structures at the molecular level. Their structure-determined physicochemical properties along with the factors governing them will be analyzed so as to identify approaches to improve their photocatalytic performance. Time-dependent density-functional theory calculations incorporating weak interlayer interactions will be applied to investigate the interaction of ionic adsorption on the surface as well as processes of charge transfer and catalytic reaction dynamics. In addition, to reveal the photocatalysis mechanism, we will examine the absorption spectra of the layered semiconductor materials whose excitation corresponds to thep-p* transition involving C-C bonds; we will also inspect fluorescence spectra resulted from the recombination of photo-generated electrons and holes. Based on their microstructures and the factors dictating their photocatalytic performance, we will unveil the physicochemical nature of this class of photocatalysis