Fabrication of Cu2O/MTiO3 (M = Ca, Sr and Ba) p-n heterojunction for highly enhanced photocatalytic hydrogen generation

Herein, a binary Cu2O/MTiO3 (M = Ca, Sr and Ba) p-n heterojunction composites are successfully designed and prepared by the hydrothermal method and following NaBH4 reduction treatment. With the help of ethanediol and polyvinylpyrrolidone, it is found that Cu2O nanoparticles (NPs) can disperse evenly on the surface of CaTiO3. Excitingly, the highest H2 production rate (HPR) of the Cu2O/CaTiO3 samples is up to 8.268 mmol g−1 h−1, which is about 344.5 times as high as that of CaTiO3 sample under the same conditions. Compared with pure CaTiO3, the photoelectric chemical performance tests manifest that photocurrent density the of Cu2O/CaTiO3 composite increases and the interface resistance decreases. These results manifest that the construction of p-n heterojunction in Cu2O/CaTiO3 sample can improve the separation and migration rates of photogenerated carrier pairs, thus accelerating the generation of H2. Additionally, the Cu2O/CaTiO3 exhibits the best HPR as compared to Cu2O/SrTiO3 and Cu2O/BaTiO3 composites, which may be attributed to the more active sites in hollow CaTiO3. This work reports a viable strategy to fabricate the Cu2O/MTiO3 p-n heterojunction, which can overcome the boundedness of single Cu2O or MTiO3 in photocatalytic performance.