Highly Asymmetric Phthalocyanine as a Sensitizer of Graphitic Carbon Nitride for Extremely Efficient Photocatalytic H₂ Production under Near-Infrared Light

Highly asymmetric zinc phthalocyanine derivative (Zn-<i>tri</i>-PcNc) with intense near-IR light (650–800 nm) absorption is utilized as a sensitizer to extend the spectral response region of graphitic carbon nitride (g-C₃N₄) from ∼450 nm to more than 800 nm. Ultraviolet–visible light (UV-vis) diffuse reflectance absorption spectra (DRS), photoluminescence (PL) spectra, time-resolved photoluminescence spectra (TRPS), and energy band structure analyses are adopted to investigate the photogenerated electron transfer process between Zn-<i>tri</i>-PcNc and g-C₃N₄ on both thermodynamics and dynamics aspects. After optimizing the photocatalytic condition and adding chenodeoxycholic acid (CDCA) as coadsorbent, Zn-<i>tri</i>-PcNc sensitized g-C₃N₄ photocatalyst shows a H₂ production efficiency of 125.2 μmol h^–1 under visible/near-IR-light (λ ≥ 500 nm) irradiation, corresponding to a turnover number (TON) of 5008 h^–1 with an extremely high apparent quantum yield (AQY) of 1.85% at 700 nm monochromatic light irradiation. The present work should be the rarely fundamental investigation on the utilization of near-IR light of solar radiation for the photocatalytic H₂ production from water splitting over a dye-sensitized semiconductor