Multichannel charge transfer in TiO2/CdS/Co2P ternary heterostructure for enhanced photocatalytic hydrogen evolution

The construction of a heterojunction with multichannel charge transfer represents an effective strategy for achieving efficient visible light photocatalytic hydrogen production. In this study, the TiO 2 /CdS/Co 2 P ternary photocatalyst was synthesized by stepwise assembly method. The UPS and work function(Φ) results confirmed the band structure and associated band bending of TiO 2 /CdS/Co 2 P, the multichannel electrons transfer from CdS to TiO 2 and CdS to Co 2 P can induce more charge carriers to participate in photocatalytic reaction. Moreover, combine with the results of 3D model charge density and photoelectric performance characterization, proves that the as-prepared ternary photocatalyst accelerates the transfer of photo-generated electrons and reduces the charge recombination rates. According to the Gibbs free energy results, Co as the additional active site is beneficial for hydrogen desorption, thus achieving a high hydrogen production result. Based on the synergistic effects, TiO 2 /55CdS/5.5Co 2 P presented a relatively high hydrogen evolution rate of 250.9 μmol h −1 under the visible light irradiation (λ ≥ 420 nm), which is almost 2 times higher than CdS/5.5Co 2 P (122.8 μmol h −1 ). This work provides theoretical guidance and practical insights for constructing ternary heterojunction structures with central-to-bilateral electron migration to achieve efficient visible-light photocatalytic hydrogen production.