Construction of Z-scheme WO3-Cu2O nanorods array heterojunction for efficient photocatalytic degradation of methylene blue

The design of tightly interfacial contact and efficient separation of photogenerated electrons and holes is an effective strategy to improve the activity of heterojunction photocatalysts. Here, a Z-scheme core-shell WO3-Cu2O nanorods array has been synthesized by one-step hydrothermal and electrochemical deposition method for photocatalytic degradation of methylene blue under visible light. The effects of electrodeposition time on the structure, morphology, and photocatalytic performance of the products were investigated in detail. It was found that the optimum Cu2O deposition time was 120 s. The UV-Vis DRS results revealed that the deposited Cu2O nanoparticles onto the surface of WO3 enhance the ability and expand the range of visible light absorption, which inhibit the recombination of photogenerated electrons and holes. Moreover, the photoelectrochemical measurement analyses show that the photocurrent response of heterojunction was significantly enhanced and the interfacial charge-transfer resistance was lowered, which further improve the separation of photogenerated carriers. Also, Z-scheme photocatalytic degradation mechanism was investigated and discussed. In consequence, the WO3-Cu2O-120 s photocatalyst showed the highest reaction rate, which was nearly 2 times than that of pristine WO3. The Z-scheme WO3-Cu2O core-shell heterojunction contribute to efficient spatial charge separation, retained the strong redox ability of photogenerated electrons-holes, which improved the photocatalytic activity.

Automated summary

In this study, a Z-scheme core-shell WO3-Cu2O nanorods array was synthesized via one-step hydrothermal and electrochemical deposition method. The effects of electrodeposition time on the performance of the products were investigated. The results showed that the optimum Cu2O deposition time was 120 s. The deposited Cu2O nanoparticles enhanced the visible light absorption and inhibited the recombination of photogenerated carriers. The photoelectrochemical measurement also demonstrated the improved separation of photogenerated carriers. Overall, the Z-scheme WO3-Cu2O core-shell heterojunction played a crucial role in enhancing the photocatalytic activity.