A new route for visible/near-infrared-light-driven H2 production over titania: Co-sensitization of surface charge transfer complex and zinc phthalocyanine

•Low cost and high efficient vis/NIR-light-driven H2 production catalyst is prepared.•In situ formation of surface LMCT complex catalyst with high H2 production activity.•TiO2 co-sensitized with ZnPc derivative (Zn-tri-PcNc) and surface LMCT complex.•Co-sensitized catalyst has relative high AQY of 0.97% at 700 nm light irradiation.

This work introduces a new strategy for visible/near-infrared (NIR) light responsive H2 production over TiO2 nanoparticles co-sensitized with zinc phthalocyanine derivative (Zn-tri-PcNc) and surface ligand-to-metal charge transfer (LMCT) complex, which is in situ formed on the TiO2 nanoparticles' surfaces by using ascorbic acid (AA). The in situ formed surface LMCT complex (AA-TiO2) exhibits obvious visible-light-responsive photoactivity (126.2 μmol/h) for H2 production with a high apparent quantum yield (AQY) of 16.1% at 420 nm monochromatic light irradiation. Moreover, the co-sensitized TiO2 nanoparticles (Zn-tri-PcNc-TiO2-AA) shows a much higher photoactivity (162.2 μmol/h) for H2 production than the surface LMCT complex, and broader spectral responsive region (400–800 nm) with a relatively high AQY value (0.97%) at 700 nm monochromatic light irradiation. The present result reveals a possible substitute for the conventional Ru(II)-bipyridyl complexes or organic dyes as sensitizer of semiconductors in the field of solar fuel conversion.

Graphical abstractA novel panchromatic light responsive photocatalyst, which shows excellent H2 production activity in the range of 400–800 nm, is successfully constructed by co-sensitization of surface charge transfer complex and zinc phthalocyanine.Figure optionsDownload full-size imageDownload as PowerPoint slide