Modification of BiOBr with cellulose nanocrystals to improve the photocatalytic performance under visible light

The activity of heterogeneous photocatalyst largely depends on its surface properties, especially the dispersibility, hydrophilicity and surface charge of the photocatalyst. Cellulose nanocrystal (CNC) is a renewable biomass material with abundant polar functional groups, which can be attached to the surface of photocatalyst to regulate its surface properties. Herein, lantern-like BiOBr/CNC composites, in which CNCs were used as a surface modifier, were insitu fabricated under ambient temperature with a simple wet-chemical method. The surface charges of CNCs were opposite to that of BiOBr, and it can be attached to the surface of BiOBr by electrostatic attraction to change its surface properties. BiOBr/CNC composites with negatively charged was favorable for the adsorption of Rhodamine B (RhB) cationic dye to its surface. Moreover, the polar groups with - OH and -SO3H on the CNCs act on the dispersity and hydrophilicity of the photocatalyst, and the photocatalyst particles can be well dispersed in aqueous solution, thus improving the photocatalytic degradation performance of RhB. The strategy to adjust the dispersibility, hydrophilicity and surface charge of materials by CNCs as a modifier is expected to apply in the surface modification to enhance the photocatalytic performance.

Automated summary

The use of cellulose nanocrystals (CNC) as a surface modifier can adjust the dispersibility, hydrophilicity, and surface charge of photocatalysts, thereby improving the photocatalytic degradation performance. The BiOBr/CNC composites with negatively charged CNCs are favorable for the adsorption of dyes onto their surface.