g-C3N4-wrapped nickel doped zinc oxide/carbon core-double shell microspheres for high-performance photocatalytic hydrogen production

The development of efficient heterojunctions with enhanced photocatalytic properties is considered a promising approach for photocatalytic hydrogen production. In this study, graphitic carbon nitride (g-C3N4)-wrapped nickel-doped zinc oxide/carbon (Ni-ZnO@C/g-C3N4) core-double shell heterojunctions with unique core-double shell structures were employed as efficient photocatalysts through an innova-tive approach. Ni doping can enhance the intensity and range of visible light absorption in ZnO, and the carbon core coupled with the hollow double-shell structure can accelerate the charge transfer rate and improve the photon utilization efficiency. Meanwhile, the construction of the Z-scheme heterojunction extended the electron-hole pair transport path. In addition, the Z-scheme charge-transfer mechanism of Ni-ZnO@C/g-C3N4 under simulated sunlight was verified by photoluminescence (PL) and electron spin resonance (ESR) experiments. As a result, the obtained photocatalyst acquired a high hydrogen evolution rate of 336.08 mu mol g(-1)h(-1), which is 36.49 times higher than that of pristine ZnO. Overall, this work may provide a pathway for the construction of highly efficient photocatalysts with unique core-double shell structures. (c) 2022 Elsevier Inc. All rights reserved.

Automated summary

Developing efficient heterojunctions with enhanced photocatalytic properties is a promising strategy for photocatalytic hydrogen production. In this study, graphitic carbon nitride-wrapped nickel-doped zinc oxide/carbon core-double shell heterojunctions were utilized as efficient photocatalysts through an innovative approach. The introduction of Ni doping enhances visible light absorption, while the core-double shell structure improves charge transfer rate and photon utilization efficiency. The constructed Z-scheme heterojunction facilitates electron-hole pair transport, and experimental results confirm the Z-scheme charge-transfer mechanism. The obtained photocatalyst exhibits a significantly higher hydrogen evolution rate compared to pristine ZnO. This work provides a pathway for the development of highly efficient photocatalysts with unique core-double shell structures.