Self-assembled supramolecular system PDINH on TiO2 surface enhances hydrogen production.

Constructing organic-inorganic hybrids is one of the hopeful strategies to improve photocatalyst performance. In this study, perylene-3,4,9,10-tetracarboxylic diimide (PDINH) and commercial TiO2 P25 are chosen as raw materials to construct a PDINH/TiO2 organic-inorganic hybrid, which has higher photocatalytic H2 production activity and photocurrent intensity than pure PDINH and TiO2, respectively. The apparent quantum efficiency for H2 production over 0.5%PDINH/TiO2 reaches as high as 70.69% using irradiation at 365 nm. Moreover, XRD, DRS, HRTEM, FT-IR, and XPS are used to characterize the crystal structure, optical absorption, morphology, molecular structure, and chemical bonds, as well as the elemental and chemical states of PDINH/TiO2 organic-inorganic hybrid. The interfaces between PDINH and TiO2, which largely determine photocatalytic performance, is also analyzed systematically. Furthermore, charge density difference (Δρ) is used to analyze the electron-ion interactions of PDINH and TiO2, and reveals that substantial charge transfer occurs from PDINH to TiO2.