Preparation of ZnO-CuO/cellulose nanocrystals composite toward water treatment

Abstract

In this study, cellulose nanocrystals (CNC) and ZnO-CuO nanostructure were successfully prepared by acid hydrolysis and hydrothermal methods, respectively. CNC had been derived through the hydrolysis reaction by sulfuric acid from the pure cellulose isolated from Vietnamese coconut husk fiber. CNC was then used as a starting material polymer for the preparation of ZnO-CuO/CNC composite. The morphological and structural measurement of CNC, ZnO/CuO and ZnO-CuO/CNC composite were investigated by FESEM-EDX, EDX mapping, FT-IR and XRD analyses. The analysis showed that the poly-dispersed, rough and rod like CNC possessed an average length of150 nm and average diameter of15 nm. EDX and XRD spectra showed that the obtained ZnO-CuO/CNC exhibited highly purified and belonged to the type of cellulose of grate I with a monoclinic structure. Via the hydrothermal method, ZnO-CuO/CNC flower-like microstructures composed of hierarchical three-dimensional (3D) aggregated hexagonal. The cluster architectures of ZnO/CuO were formed at 120 oC in 10 h. A possible growth mechanism for the controlled organization of primary building units into ZnO-CuO nanostructure and 3D flower-like ZnO-CuO/CNC architectures was proposed. The result demonstrated that the prepared ZnO-CuO/CNC composite exhibited a high removal efficiency (93%) of methylene blue of the concentration of 20 mg/L after 30 min treatment.