The role of electron transfer in photocatalysis: Fact and fictions

Interfacial electron transfer at semiconductor nanoparticles is a fundamental process that is relevant to many applications in photocatalysis such as wastewater cleaning, air cleaning and energy production. Fundamental understanding of the dynamic of the electron transfer is of crucial importance for the understanding of the fundamental concepts of photocatalytic processes and hence results in understanding and industrialization of photocatalytic reactions as well as a rational design of the photocatalytic systems.This review summarizes the progress in understanding electron transfer dynamics from semiconductor nanoparticles to the electron acceptor molecules. The approaches to improve the electron transfer efficiency will be also reviewed. Of particular focus will be the advancement of methodology as well as overview of some new highlights in electron transfer reactions at TiO2/liquid interface.

Graphical abstract.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Electron transfer plays a key role in photocatalysis. ► Electron transfer dynamics measured by flash photolysis, pulse radiolysis or stopped flow. ► Electron transfer efficiency depends on photocatalyst size, surface composition and morphology. ► The electron transfer rate was found to increase with increasing the driving force. ► New findings on the electron transfer reactions at TiO2 nanoparticles are reviewed.