Reduced recombination and low-resistive transport of electrons for photo-redox reactions in metal-free hybrid photocatalyst

Photoinduced charge separation against their faster recombination is a rate determinant for photocatalytic proton reduction to hydrogen. Dissociation of electron-hole pairs into free electrons and holes in carbon nitrides greatly suffered from the inherent high recombination rate. This study has shown that coupling two energetically optimized, but with different phases carbon nitrides in the form of hybrid could significantly inhibit the charge carrier recombination and facilitate the overall charge transfer processes. It is also found that the potential gradient in this homojunction delocalizes electrons and holes, and increases the spatial charge separation. Therefore, this leads to a record high apparent quantum efficiency of 5% for photocatalytic H ₂ production from water under visible light irradiation in the absence of a precious metal (e.g., Pt) cocatalyst.