Synergistic Functionality of Dopants and Defects in Co‐Phthalocyanine/B‐CN Z‐Scheme Photocatalysts for Promoting Photocatalytic CO2 Reduction Reactions

Abstract The realization of solar‐light‐driven CO 2 reduction reactions (CO 2 RR) is essential for the commercial development of renewable energy modules and the reduction of global CO 2 emissions. Combining experimental measurements and theoretical calculations, to introduce boron dopants and nitrogen defects in graphitic carbon nitride (g‐C 3 N 4 ), sodium borohydride is simply calcined with the mixture of g‐C 3 N 4 (CN), followed by the introduction of ultrathin Co phthalocyanine through phosphate groups. By strengthening H‐bonding interactions, the resultant CoPc/P‐BNDCN nanocomposite showed excellent photocatalytic CO 2 reduction activity, releasing 197.76 and 130.32 µmol h −1 g −1 CO and CH 4 , respectively, and conveying an unprecedented 10‐26‐time improvement under visible‐light irradiation. The substantial tuning is performed towards the conduction and valance band locations by B‐dopants and N‐defects to modulate the band structure for significantly accelerated CO 2 RR. Through the use of ultrathin metal phthalocyanine assemblies that have a lot of single‐atom sites, this work demonstrates a sustainable approach for achieving effective photocatalytic CO 2 activation. More importantly, the excellent photoactivity is attributed to the fast charge separation via Z‐scheme transfer mechanism formed by the universally facile strategy of dimension‐matched ultrathin (≈4 nm) metal phthalocyanine‐assisted nanocomposites.