BiOI/BiVO4p–n heterojunction with enhanced photocatalytic activity under visible-light irradiation

• p-BiOI/n-BiVO4 was prepared via a coprecipitation process.
• BiOI/BiVO4 exhibits a wide visible-light absorption performance and well crystallinity.
• Enhanced photocatalytic activity was due to the BiOI/BiVO4 heterojunction.
• BiOI/BiVO4 has a high stability and long-time reusability.
• The photocatalytic mechanism is proposed.

A novel visible-light-sensitive BiOI/BiVO4 photocatalyst with a p–n heterojunction structure was synthesized through a facile coprecipitation method. The physical and chemical properties of as-synthesized BiOI/BiVO4 composites were characterized by XRD, XPS, BET, SEM, EDS, HRTEM, photoluminescence spectrum and UV–DRS respectively. The photocatalytic activity of the prepared photocatalysts was evaluated by photodegrading methylene blue and killing of Pseudomonas aeruginosa (P. aeruginosa) under visible light irradiation. The results showed that the 30%BiOI/BiVO4 (molar ratio of I:V = 3:7) exhibits the higher photocatalytic activity than the pristine BiOI and BiVO4. Moreover, the sterilization mechanism involved in the photocatalytic disinfection process was studied by captive species trapping experiments. The result revealed that hydroxyl radical (OH) and holes (h+) are the main reactive species for killing of P. aeruginosa under visible light irradiation. In addition, after five recycles for killing of P. aeruginosa under visible light irradiation, 30%BiOI/BiVO4 does not exhibit significant loss of photocatalytic activity. The results confirm that the synthesized 30%BiOI/BiVO4 photocatalyst has long-time reusability and good photocatalytic stability. The photocatalyst shows potential application in marine antifouling.

Figure optionsDownload as PowerPoint slide