Nickel-doped microtubular CeVO4 inspired by wood powder structure for visible light photocatalytic degradation of methylene blue and bacterial inactivation

Abstract

In this study, inspired by natural wood powder structure, nickel-doped microtubular cerium vanadate (Ni/T-CeVO4) was obtained using wood powder as a biological template. Photocatalytic experiments under visible light revealed that Ni/T-CeVO4-3wt possessed the highest photocatalytic activity, with a degradation efficiency of up to 99 % for methylene blue. The enhanced photocatalytic performance was not only attributed to the microtubule wood powder structure assigned the composite a larger specific surface area but also the nickel doping narrowed the band gap of the composites while introducing more oxygen vacancies. The rapidly generated current in transient photocurrent responses and small arc radius in electrochemical impedance spectra further indicated the higher photogenerated carrier separation and smaller photogenerated electron transfer resistance within the composite. ESR spin-trapping tests proved that O2− and OH dominated the photocatalytic process. Furthermore, owing to its unique structural characteristics, the composite showed excellent photocatalytic antibacterial activity against Staphylococcus aureus and Escherichia coli. The present study provides a theoretical basis for developing efficient dual-effect photocatalysts using visible light to remove organic dyes and pathogenic bacteria from the water environment.