ABSTRACT
Semiconducting materials play a central role in photocatalytic systems which utilize solar energy to create new chemical bonds. While photocatalytic systems could generate a clean, renewable source of energy to meet the world’s ever-rising energy demands, semiconducting materials possessing the necessary combination of efficiency, stability, and cost have yet to be identified. In the search for improved materials for these applications, scanning electrochemical microscopy (SECM) has proven to be a valuable tool for providing fundamental insights into photocatalytic reactions at semiconductor-liquid interfaces and screening the performance of novel semiconductor compositions. This chapter discusses the basics of how SECM techniques can be applied to the study of photocatalytic systems, different SECM experimental configurations which have been demonstrated, and their application in materials discovery and fundamental investigations. Specific topics include the optical fiber-based screening of oxide and non-oxide photocatalysts, studies of photocatalytic reaction kinetics using the substrate generation-tip collection (SG-TC) and surface interrogation modes, and emerging experimental methods such as dual-function SECM probes for correlated high resolution optical-electrochemical studies and scanning electrochemical cell microscopy (SECCM) techniques. The strengths and weaknesses of each configuration are discussed with selected examples from the literature. Challenges, new experimental strategies, and future applications are provided at the outset which may help advance this field moving forward.
