Heterogeneous photocatalysis

Solar-light driven photocatalysis has been widely accepted as a green and potential method for the generation of H2 as a clean, renewable energy source for CO2 photoreduction, and for pollutant elimination. One of the key limiting factors of semiconductor photocatalysts is the fast charge carrier recombination, which leads to low catalytic efficiency. In this context, diverse strategies have been developed to enhance the photoconversion efficiency of photocatalysts, but the combination of two semiconductors to form a heterojunction photocatalyst is considered a most efficient way for enhancing the photocatalytic performance, due to the facile charge separation through the band alignment between the two semiconductors. Among these heterojunctions, Z-scheme photocatalysts, similar to that of a type-II heterojunction photocatalyst represents a rational strategy for enhancing the photocatalytic performance and solar-energy conversion. Their effectiveness for spatially separate photogenerated electron–hole pairs and for optimizing the reduction and oxidation ability makes them very efficient photocatalytic systems. The present chapter includes a broad overview of the synthesis and the potential applications of Z-scheme heterostructures in photocatalysis domains such as water splitting, organic pollutant removal, and CO2 reduction.