Insight into the dual-channel charge-charrier transfer path for nonmetal plasmonic tungsten oxide based composites with boosted photocatalytic activity under full-spectrum light

Abstract

The photocatalytic activities of the semiconductor-based photocatalysts are often practically limited by the insufficient photoinduced charge-carrier separation, so the construction of efficient charge transfer path is vital for highly efficient photocatalysis reaction system. In this study, we reported a rational designed novel hierarchical W18O49/g-C3N4 composite with boosted photocatalytic activity through the manipulated flow of dual-channel charge-carrier separation and transfer process. Due to the efficient strategy about the combination of the morphology structure and the regulation of band structure, the prepared composites present enhanced photocatalytic performance in both full-spectrum light and near-infrared (NIR) light irradiation. Under the optimum condition, the prepared W18O49/g-C3N4 composites show high degradation efficiency for both colorful methylene blue (MB) and colorless ciprofloxacin (CIP). Mechanistic characterizations and control experiments demonstrate the cooperative synergy effect of dual-channel charge-carrier transfer path in such W18O49/g-C3N4 composites, including Z-scheme charge transfer and surface plasmon resonance effect, which interactively leads to the boosted photocatalytic performance. The match of the band gap results in the Z-scheme reaction mechanism and brought both the strong redox ability and promotion of the transfer rate of the photogenerated charges; the LSPR effect of nonmetal plasmonic W18O49 can broaden the light response of the prepared W18O49/g-C3N4 to NIR region, leading to enhanced utilization of solar energy. Moreover, the oxygen vacancies in this reaction system which played important role in the photocatalytic process have been fully studied by the appropriate design of the control experiments.