Heterojunction material BiYO 3 /g-C 3 N 4 modified with cellulose nanofibers for photocatalytic degradation of tetracycline.

Cellulose nanofibers (CNFs) with large specific surface area and superb adsorption capacity are excellent photocatalyst carriers. In this study, heterojunction powder material BiYO/g-CN was successfully synthesized for the photocatalytic degradation of tetracycline (TC). The photocatalytic material BiYO/g-CN/CNFs was obtained by loading BiYO/g-CN on CNFs using electrostatic self-assembly method. BiYO/g-CN/CNFs exhibit a fluffy porous structure and large specific surface area, strong absorption in the visible light range, and the rapid transfer of photogenerated electron-hole pairs. Polymer-modified photocatalytic materials overcome the disadvantages of powder materials that are easy to reunite and difficult to recover. With synergistic effects of adsorption and photocatalysis, the catalyst demonstrated excellent TC removal efficiency, and the composite maintained nearly 90 % of its initial photocatalytic degradation activity after five cycles of use. The superior photocatalytic activity of the catalysts is also attributable to the formation of heterojunctions, and the heterojunction electron transfer pathway was confirmed by experimental studies and theoretical calculations. This work demonstrates that there is great research potential in using polymer modified photocatalysts to improve photocatalyst performance.