NaBiS2 decorated polysaccharide sponges for adsorption–photocatalytic degradation of dye under visible light illumination

Dye is emissions aggravating aquatic ecosystem pollution, and photocatalysis is considered the most appealing option to remove dyes by degradation. However, the current photocatalysts suffer from agglomeration, large bandgaps, high mass transfer resistance, and high operation cost. Herein, we present a facile hydrothermally induced phase separation and in situ synthesis strategy for fabrication of sodium bismuth sulfide (NaBiS2)-decorated chitosan/cellulose sponges (NaBiCCSs). The NaBiCCSs demonstrate unique polysaccharide cellular structure (150-500 μm), uniformly immobilized NaBiS2 nanoparticles (70-90 nm), narrow bandgap (1.18 eV), high photocurrent (0.74 μA/cm2), and outstanding compressibility. Benefiting from the characteristics and the high affinity to dyes, the NaBiCCSs provide innovative synergistic adsorption-photocatalytic degradation model for dye removal, attaining a superior methylene blue removal rate of 98.38 % under visible light illumination and offering good reusability. This study offers a sustainable technical solution for dye contaminant removal.