Heterojunction within dual electric fields dynamically tailoring charge transfer to surface redox active sites for efficient H2 generation

Abstract

Flying broom-like heterojunction photocatalysts with internal electric field synergizing polarized field has been constructed by spontaneously assembling CuO nanoparticles on polarized g-C3N4 microfibers (p-C3N4Fs) with using a facile hydrothermal method. Theoretical prediction and characterizations confirm that, photo-generated electrons and holes are dynamically transferred to reductive sites of pyridine-like N in p-C3N4Fs and oxidative sites of Cu atom in CuO for H2O splitting within the dual electric fields, respectively. Stoichiometric H2 and O2 evolution with solar energy conversion into H2 energy of 1.22 % has been achieved under AM 1.5G irradiation in photocatalytic H2O overall splitting by heterojunction photocatalytic mechanism of translation, rotation, transformation of protons and intermediates. The rational photocatalyst design on heterojunction with dual electric fields breaks the long-term thought of regulating charge carriers only by internal electric field, which will provide a unique perspective to deepen the kinetic study on the spatial separation and directional migration of photogenerated charges to the surface redox active sites for solar energy conversion.