Carbon-doped ZnO aided by carboxymethyl cellulose: Fabrication, photoluminescence and photocatalytic applications

To explore and develop environment friendly inorganic materials for effectively degrading organic pollutants, carbon-doped ZnO (C-ZnO) nanoparticles with intriguing properties have been synthesized by hydrothermal method with the assistance of sodium carboxymethyl cellulose (CMC) and subsequent high-temperature calcination. The C-ZnO is found to be well crystallized and shows one phase of hexagonal wurtzite ZnO while using a proper amount of CMC. The carbon entering the lattice of ZnO as heteroatom is evidenced by XRD, EDS and XPS analyses, which presumably takes place in the calcining process. The prepared C-ZnO displays well-dispersed nano flower-like morphology with a band gap 3.15 eV (mean value). This narrowing band gap relative to the non-doped ZnO (3.24 eV) would initiate interesting changes of properties. A relatively strong deep-level photoluminescent emission has been attributed to the defects of doping carbon; the near-band-edge emission is quenched compared with the non-doped ZnO, indicative of more defects. As evidenced by EIS, the carbon doping improves charge transfer efficiency of our materials. All these aspects allow for good catalytic performance of the newlyprepared C-ZnO under low-power (6 W) UV irradiation. The sample of C-ZnO-0.3 has the highest photodegradation efficiency of 98%, which is better than TiO2 P25. (C) 2016 Elsevier B.V. All rights reserved.