In situ charge carrier dynamics of semiconductor nanostructures for advanced photoelectrochemical and photocatalytic applications

Using in situ ultrafast laser spectroscopic techniques to monitor the charge dynamics of semiconductor photocatalysts under operating conditions is essential for digging out the veritable interactions between charge carriers and the reactive species. This real-time observation is desirable for optimizing individual components and their integration in advanced photoelectrochemical (PEC) and photocatalytic systems, which can achieve the “Holy Grail” of solar energy harvesting and solar fuel generation. This Review summarizes the recent developments of employing transient absorption spectroscopy for in situ measurements of charge dynamics on semiconductor nanostructures. The implications in the PEC and photocatalytic reactions toward hydrogen production and carbon dioxide reduction will be discussed, along with future outlooks and perspectives.