Honeycomb like CdS/sulphur-modified biochar composites with enhanced adsorption-photocatalytic capacity for effective removal of rhodamine B

Honeycomb like CdS/Sulphur-modified biochar composites (CdS/S-BC) with excellent adsorption-photocatalytic activity was prepared by impregnation and calcination methods. Sulphur-modified biochar (S-BC) has manifested the high porosity and large specific surface area because of the modification of S. 1-CdS/S-BC (1 represents the CdS molar amount) exhibits high synergistic adsorption-photocatalytic degradation effect for RhB, and the RhB removal efficiency of 1-CdS/S-BC up to 99.18% within 60 min under visible light (lambda >= 420 nm) irradiation. Compared with single materials BC, S-BC, CdS, the outstanding RhB removal performance of 1-CdS/S-BC was not only ascribed to the large specific surface area and abundant reactive sites provided by S-BC, but also can significantly promote the migration and utilization of photoinduced carriers. The CdS/S-BC adsorption mechanism studies demonstrated that hydrogen bond and electrostatic interaction are main action of adsorption, meanwhile the superoxide radicals (center dot O-2(-)) are the main active species in the photocatalytic degradation process. This study provided an available strategy for the efficient utilization of green biomass to prepare adsorption-photocatalytic materials.

Automated summary

The CdS/sulphur-modified biochar composites exhibit excellent adsorption-photocatalytic activity for efficient dye degradation. The superior performance is attributed to the large specific surface area, abundant reactive sites provided by the composite materials, and the promotion of migration and utilization of photoinduced carriers.