Ti-O-C interfacial bonding-induced electron transport channels and structural distortions enhance the photocatalytic hydrogen evolution activity of anatase-TiO2/carbon nitride heterojunction

Photocatalytic hydrogen production technology can convert the solar energy directly into the storable hydrogen energy, providing a feasible way for the efficient utilization of renewable energy. Constructing heterojunction is an important method to implement the solar-drived hydrogen production from water splitting. Based on thermally stripped carbon nitride (TCN), in situ hydrolysis and thermal polycondensation are adopted to prepare anatase-TiO2/TCN heterojunction. The maximum H2 yield of anatase-TiO2/TCN reaches 31.87 mmol h−1g−1, 14.82 times higher than that of TCN and 17.61 times than that of anatase-TiO2. The experimental analysis and theoretical calculations indicate that the strong interaction of Ti-O-C bonding between anatase-TiO2 and TCN induces the formation of heterojunction. Ti-O-C bonding serves as a connecting bridge for heterojunction, providing the convenient transfer channels for photogenerated carriers. The electron transfer from anatase-TiO2 to TCN is accelerated via the storage and relay action of bridging oxygen. The distorsion of TCN heptazine skeleton promotes the intra ring transfer of electrons between C and N atoms and enhances the electron delocalization, thereby benefiting for hydrogen ion reduction. This work provides a feasible preparation strategy for anatase-TiO2/TCN heterojunction photocatalysts with efficient hydrogen production, highlighting the effect of interface bonding on accelerating the electron transfer between heterojunction.