A fluorescent adsorption materials based on cellulose fibers and ferric hydroxide from steel slag with carbon dots for adsorption and detection of Cr6+

Hexavalent chromium (Cr 6+ ) is a highly toxic heavy metal ion pollutant that poses serious a threat to human health. In this work, iron hydroxide (Fe(OH) 3 ) derived from steel slag (SS) was used as the raw material, carboxymethyl cellulose (CMC) as the skeleton, and carbon quantum dots (CDs) as the fluorescent probe to successfully prepare a composite material with Cr 6+ adsorption and fluorescence detection properties (Fe(OH) 3 @CMC-CDs). The Fe(OH) 3 @CMC-CDs exhibited a specific surface area of 112.52 m 2 /g and a three-dimensional porous architecture, with Fe(OH) 3 uniformly distributed within the cellulose network. The adsorption results showed that adsorption behavior of Cr 6+ on Fe(OH) 3 @CMC-CDs followed the pseudo-second-order kinetic model and Langmuir model, with a maximum adsorption capacity of 214.13 mg/g at 333 K. In addition, Fe(OH) 3 @CMC-CDs showed sensitive fluorescence detection performance for Cr 6+ , and the detection limit was 7.21 × 10 −5  mol/L. Reusability experiment demonstrated that Fe(OH) 3 @CMC-CDs had excellent recyclability for Cr 6+ , after 5 adsorption-desorption cycles, the removal efficiency for Cr 6+ above 87%. This study introduces an innovative approach to preparing a dual-functional composite material with both adsorption and detection properties using Fe(OH) 3 derived from steel slag. It achieves the resource recovery and value-added utilization of steel slag, and provides new insights into the removal of Cr 6+ and the design of multifunctional adsorbent.