Revisiting the Key Optical and Electrical Characteristics in Reporting Photocatalysis of Semiconductors

Abstract

Photocatalysis has been studied and considered as a green and effective approach in addressing environmental pollution. However, factors that affect photocatalytic performance have not been systematically studied. In this work, we have presented a comprehensive roadmap for characterizing, interpreting, and reporting semiconductors' electrical and optical properties through routinely used techniques such as diffuse reflectance spectroscopy (DRS), electrochemical techniques (Mott-Schottky plots), photoluminescence (PL), X-ray photoelectron spectroscopy (XPS ), and ultraviolet photoelectron spectroscopy (UPS) in the context of photocatalysis. Having deeply and precisely studied the band structure of three representative photocatalysts, we have presented and highlighted essential information and details, which are critical and beneficial for studies of (1) band alignments, (2) redox potentials, and (3) defects. Further works with a comprehensive understanding of band structure are desirable and hold great promise.