Vacancy engineering in nanostructured semiconductors for enhancing photocatalysis

Semiconductor vacancy engineering has remained a prominent growing field over the past several decades. Modulating electronic structures and surface properties has sparked considerable interest in vacancy-modified photocatalysts. Given vacancy-mediated photocatalysis has only been developed for a relatively short period, significant advance has been made in enhancing light absorption over the full solar spectrum, the efficiency of charge transfer and separation and surface reaction kinetics. This review seeks to highlight the recent impressive progress in vacancy-enhanced photocatalysis. First, we summarize the crafting and characterization of vacancies after defining the classification of vacancies. Second, current developments of semiconductor vacancy engineering in several photocatalysts (i.e., metal oxides, hydroxides, sulfides, Sillen phase related bismuth-containing materials and g-C3N4) are emphasized, focusing on the mechanism of vacancies in regulating the photocatalytic performance. Finally, prospects and challenges regarding vacancy engineering of photocatalytic materials are concluded.