Current advances in all-solid-state dual Z-Scheme heterojunction photocatalysts

<p indent="0mm">Photocatalytic technology has shown great potential in addressing energy and environmental issues. However, factors such as low visible light utilization efficiency, high carrier recombination rate, and poor oxidation–reduction ability have led to unsatisfactory photocatalytic activity of single-component semiconductors. Therefore, developing effective strategies to enhance the photocatalytic activity of semiconductors is crucial for the application of photocatalytic technology. By constructing dual Z-scheme heterojunctions, the lifetime of carriers can be prolonged, the range of light absorption can be extended, the concentration of photo-generated carriers can be increased, and the oxidation–reduction potential can be enhanced. At the same time, dual Z-scheme heterojunctions have multiple electron transfer channels which facilitate photoexcited electron migration and promote efficient separation of electron–hole pairs. In recent years, dual Z-scheme heterojunctions have undergone rapid development and their theoretical systems have become relatively mature. However, there are few reviews on dual Z-scheme heterojunction photocatalysts. This paper provides a detailed introduction to the types of binary and dual Z-scheme heterojunctions, summarizes the advantages of dual Z-scheme heterojunctions in improving photocatalytic efficiency, focuses on verifying methods for dual Z-scheme heterojunctions, and comprehensively discusses the applications of dual Z-scheme heterojunctions in pollutant treatment, water splitting to produce hydrogen, CO₂ reduction, photocatalytic nitrogen fixation, and cell inactivation. The challenges faced by dual Z-scheme heterojunction photocatalysts are discussed along with possible future directions. The summary and outlook presented in this paper will provide useful references for developing more efficient dual Z-scheme heterojunctions.