Ultrathin ZnIn2S4 nanosheets decorating PPy nanotubes toward simultaneous photocatalytic H2 production and 1,4-benzenedimethanol valorization

It is highly desirable to make full use of photogenerated charge carriers by elaborately designing high-efficiency multifunctional photocatalysts with achieving bi-value-added production. Herein, we report the photocatalyst with ultrathin ZnIn2S4 nanosheets decorating polypyrrole nanotubes, thanks to the matched bandgap, is capable of harvesting visible light for photocatalysis, during which the photoexcited electrons and holes are used for H2 evolution and 1,4-benzenedimethanol (BDM) upgrading oxidation, respectively. Comprehensive experiments and density functional theory calculations indicate that the photoinduced electrons tend to be transferred to the inner PPy nanotubes of PPy@ZIS composite for photocatalytic H2 generation, while the photoexcited holes favorably oxidize BDM into 1,4-phthalaldehyde (PAD) on outer ZIS nanosheets of PPy@ZIS composite. The optimized PPy@ZIS exhibits an apparent quantum efficiency of 6.43% (at 420 nm) for photocatalytic H2 evolution and BDM valorization into PAD at a rate of 735 μmol g−1 h−1, remarkably promoting the utilization efficiency of charge carriers. Ultrathin ZnIn2S4 nanosheets are successfully decorated on PPy nanotubes to form hierarchical PPy@ZnIn2S4 composite, which presents highly desirable photocatalytic properties for simultaneous production of H2 and 1,4-phthalaldehyde via water reduction and 1,4-benzenedimethanol selective oxidation, respectively. [Display omitted] •Hierarchical PPy@ZnIn2S4 nanocomposite was successfully fabricated.•Simultaneous photocatalytic H2 evolution and 1,4-benzenedimethanol selective oxidation.•PPy nanotubes act as an electrons collector to boost the H2 production performance.•Selective oxidation of 1,4-benzenedimethanol to 1,4-phthalaldehyde is the carbon-centered free radical process.