Metal Poly(heptazine imides) as Multifunctional Photocatalysts for Solar Fuel Production

Solar‐driven photocatalysis employing particulate semiconductors represents a promising approach for sustainable production of valuable chemical feedstock. Metal poly(heptazine imide) ( M PHI), a novel 2D ionic carbon nitride, has been recognized as an emerging photocatalyst with distinctive properties. In this minireview, we first delineate the forefront innovations of M PHI photocatalysts, spanning from synthetic strategies and solving structures to the exploration of novel properties. We place special emphasis on the structural design principles aimed at developing high‐performance M PHI systems toward photocatalytic solar fuel production such as H 2 evolution, H 2 O oxidation, H 2 O 2 production and CO 2 reduction. Finally, we discuss crucial insights and challenges in leveraging highly active MPHIs for efficient solar‐to‐chemical energy conversion.