Au nanoparticles decorated Kapok fiber by a facile noncovalent approach for efficient catalytic decoloration of Congo Red and hydrogen production

Abstract

A facile and eco-friendly noncovalent self-assembly approach was employed to immobilize Au nanoparticles (AuNPs) onto a natural tubular Kapok fiber (KF) and used for the catalytic reducing decoloration of Congo Red (CR) dye and simultaneous hydrogen production. AuNPs fail to be directly attached on KF or carboxylated KF (CKF), but the introduction of chitosan (CTS) as a “bridge” led to the stable immobilization of AuNPs on KF or CKF with a well-dispersed distribution, as shown by UV–vis, XRD, SEM and TEM analyses. The resultant KF (or CKF)/CTS/AuNPs nanocomposites show excellent catalytic activity and stability for the catalytic reducing decoloration of CR dye, and the color of CR solution can be rapidly faded within 3min at the low catalyst dosage of 0.3g/L. The catalytic activity of the nanocomposite can be maintained after being treated with sonication or 1mol/L acid for 20min. Along with the catalytic decoloration of CR, hydrogen was simultaneously produced and can be collected as a clean green fuel, and the maximum yield of hydrogen reaches 430mL/L (CR solution, 20mg/L). Thus, the nanocomposite can be used as a catalyst to decolor dye wastewater and produce hydrogen by one-step process. Moreover, the reported strategy follows the sustainable development idea of “from nature, for nature, into the nature” and promotes the use of naturally renewable resources to produce promising and eco-friendly functional materials for various applications.