No abstract

In this study, commercial graphene ink has been used as a cost-effective modifier for glassy carbon electrode (GCE) surface modification. The excellent conductivity and defects triggered electrocatalytic property of the graphene ink showed a superior performance in electrochemical sensing. Galantamine, an alkaloid isolated from Lycoris, has been selected as an analyte for evaluating the graphene inkmodified GCE. A clear signal enhancement with reduction of overpotential was observed using a GCE after a simple graphene ink surface modification process. A linear detection range from 20 μM to 180 μM of galantamine was recorded on the proposed electrode with a low limit of detection of 4.1 μM.

Waste cassava fiber and tea polyphenols were used as carrier materials and reducing agents, respectively, to prepare nano-iron loaded cassava fiber composite (CF-FeNPs). This work investigated the factors affecting the removal of Cr(Ⅵ) by CF-FeNPs under different environmental conditions and the removal mechanism. The SEM characterization results show that as the initial Fe2+ concentration increases, the amount of nano-iron on the surface of the composite material increases. The results show that the increases of the initial Fe2+ content and dosage of CF-FeNPs can enhance the removal rate. Meanwhile, the decrease of the initial concentration of Cr(Ⅵ) solution and pH also beneficial for the removal performance. When pH=2.0 and the initial concentration of Cr(Ⅵ) is 10 mg/L, the removal rate of hexavalent chromium by CF-FeNPs can reach 81.4% within 2 h. The reaction conforms to the pseudo first-order kinetic model. The results of this study can provide technical reference for the remediation and treatment of Cr(VI)-containing wastewater.