Graphitic carbon nitride can be imprinted with a twisted hexagonal rod-like morphology by a nanocasting technique using chiral silicon dioxides as templates. The helical nanoarchitectures promote charge separation and mass transfer of carbon nitride semiconductors, enabling it to act as a more efficient photocatalyst for water splitting and CO2 reduction than the pristine carbon nitride polymer. This is to our knowledge a unique example of chiral graphitic carbon nitride that features both left- and right-handed helical nanostructures and exhibits unique optical activity to circularly polarized light at the semiconductor absorption edge as well as photoredox activity for solar-to-chemical conversion. Such helical nanostructured polymeric semiconductors are envisaged to hold great promise for a range of applications that rely on such semiconductor properties as well as chirality for photocatalysis, asymmetric catalysis, chiral recognition, nanotechnology, and chemical sensing.

Ferrocene moieties were heterogenized onto carbon nitride polymers by a covalent -C=N- linkage bridging the two conjugation systems, enabling the merging of the redox function of ferrocene with carbon nitride photocatalysis to construct a heterogeneous Photo-Fenton system for green organocatalysis at neutral conditions. The synergistic donor-acceptor interaction between the carbon nitride matrix and ferrocene group, improved exciton splitting, and coupled photocatalytic performance allowed the direct synthesis of phenol from benzene in the presence of H2 O2 under visible light irradiation. This innovative modification method will offer an avenue to construct functionalized two-dimensional polymers useful also for other green synthesis processes using solar irradiation.

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Graphitic carbon nitride can be imprinted with a twisted hexagonal rod-like morphology by a nanocasting technique using chiral silicon dioxides as templates. The helical nanoarchitectures promote charge separation and mass transfer of carbon nitride semiconductors, enabling it to act as a more efficient photocatalyst for water splitting and CO 2 reduction than the pristine carbon nitride polymer. This is to our knowledge a unique example of chiral graphitic carbon nitride that features both left-and right-handed helical nanostructures and exhibits unique optical activity to circularly polarized light at the semiconductor absorption edge as well as photoredox activity for solar-to-chemical conversion. Such helical nanostructured polymeric semiconductors are envisaged to hold great promise for a range of applications that rely on such semiconductor properties as well as chirality for photocatalysis, asymmetric catalysis, chiral recognition, nanotechnology, and chemical sensing.

In the paper, the synthesis of ZnO/TiO 2 nanocomposites with different main parts (TiO 2 or ZnO) is studied. When TiO 2 is the main part of the ZnO/TiO 2 heterojunction photocatalysts (ZnO/TiO 2 ), the photocatalytic activity is decreased rapidly with the increase of the amount of ZnO. The reason may be attributed to the relative p−n junction (p-ZnO/ n-TiO 2 ) produced between ZnO and TiO 2 . The migration directions of the electrons and holes in the relative p−n junction are opposite to the transfer directions of the photogenerated electrons and holes in the valence band (VB) and conduction band (CB). However, when ZnO is the primary part of the heterojunction photocatalysts (TiO 2 /ZnO), the photocatalytic activity of the samples increases with the increase of the TiO 2 amount up to 5% (95% ZnO/TiO 2 ). The reason may be that the migration directions of the electrons and holes in the relative p−n junction (p-TiO 2 /n-ZnO) are the same as the transfer directions of the photoexcited electrons and holes in VB and CB between the two semiconductors. It is proposed that the conductivity of the heterojunction photocatalyst will be changed with the difference of content for the two semiconductors, which in turn affects the migration directions of the electrons and holes in the heterojunctions and their photocatalytic activity.