Enhanced photocatalytic hydrogen production under visible light of an organic-inorganic hybrid material based on enzo[1,2-b:4,5-b']dithiophene polymer and TiO2

Titanium dioxide (TiO2) has been limited in photocatalysis due to its wide band gap (3.2 eV) and limited absorption in the ultraviolet range. Therefore, organic components have been introduced to hybrid with TiO2 for enhanced photocatalytic efficiency under visible light. Here, we report that benzo[1,2-b:4,5-b']dithiophene polymer was an ideal organic material for the preparation of a hybrid material with TiO2. The energy band gap of the resulting hybrid material decreased to 2.9 eV and the photocatalytic hydrogen production performance reached 745.0 µmol g−1 h−1 under visible light irradiation. Meanwhile, the material still maintained the stability of hydrogen production performance after 40 h of photocatalytic cycles. The analysis of the transient current response and electrochemical impedance revealed that the main reasons for the enhanced water splitting of the hybrid materials were the faster separation of electron hole pairs and the lower recombination of photocarrier ions. Our findings suggest that polythiophene is a promising organic material for exploring hybrid materials with enhanced photocatalytic hydrogen production.