Ultrathin Phosphate‐Modulated Co Phthalocyanine/g‐C3N4 Heterojunction Photocatalysts with Single Co–N4 (II) Sites for Efficient O2 Activation

Abstract Realization of solar‐driven aerobic organic transformation under atmospheric pressure raises the great challenge for efficiently activating O 2 by tailored photocatalysts. Guided by theoretical calculation, phosphate groups are used to induce the construction of ultrathin Co phthalocyanine/g‐C 3 N 4 heterojunctions (CoPc/P‐CN, ≈4 nm) via strengthened H‐bonding interfacial connection, achieving an unprecedented 14‐time photoactivity improvement for UV–vis aerobic 2,4‐dichlorophenol degradation compared to bulk CN by promoted activation of O 2 . It is validated that more • O 2 − radicals are produced through the improved photoreduction of O 2 by accelerated photoelectron transfer from CN to the ligand of CoPc and then to the abundant single Co–N 4 (II) catalytic sites, as endowed by the matched dimension, intimate interface even at the molecular level, and high CoPc dispersion of resulted heterojunctions. Interestingly, CoPc/P‐CN also exhibits outstanding photoactivities in the aerobic oxidation of aromatic alcohols. This work showcases a feasible route to realize efficient photocatalytic O 2 activation by exploiting the potential of ultrathin metal phthalocyanine (MPc) assemblies with abundant single‐atom sites. More importantly, a universal facile strategy of H‐bonding‐dominating construction of MPc‐involved heterojunctions is successfully established.