Electrodeposited ZnO Nanorods as Efficient Photoanodes for the Degradation of Rhodamine B

Abstract

Herein the synthesis of ZnO nanorods (NRs) by means of the one‐ and two‐step electrochemical deposition (ECD) process is focused upon. A comparison of the crystal structure, morphology, optical properties, and photoelectrocatalytic (PEC) activities of nanostructured ZnO cultivated by the two methods is conducted. X‐ray diffraction (XRD) analysis reveals that all samples annealed at 300 °C are polycrystalline and have a hexagonal (wurtzite) structure and significant improvement in the crystallinity of the sample deposited by the two‐step process. The morphological characterizations show that the NRs are well hexagonal and well oriented in the same sample. The optical spectra show a transmittance higher than 70% and direct bandgaps of 3.12 and 3.04 eV for the samples synthesized by one‐step and two‐step electrodeposition, respectively. The PEC properties of the films obtained are studied and reveal an efficient and rapid rhodamine B (RhB) azo dye degradation. In addition, the scavengers of reactive species as well as the kinetics during degradation are also studied and show that the superoxide radicals contribute significantly in degradation.

Improvement of the photocatalytic performance of ZnO thin films in the UV and sunlight range by Cu doping and additional coupling with Cu2O

“…From Fig. 9, the linear relationship, observed between the irradiation time and ln(C/C t ) values with a correlation coefficient R 2 > 0.9562, confirms that the photocatalytic degradation kinetics follows the first order reaction [40]. The degradation rate constants (k) of the three dyes were determined from the data fitted by equation ( 5) and the values are given in Table 1.…”

High UV and Sunlight Photocatalytic Performance of Porous ZnO Nanostructures Synthesized by a Facile and Fast Microwave Hydrothermal Method

“…ZnO nanostructures can be produced through a variety of synthesis methods, such as electrodeposition [ 25 ], chemical bath deposition [ 26 ], chemical vapor deposition [ 27 ], and solvothermal [ 28 ] or hydrothermal [ 29 , 30 ] synthesis, either by conventional or microwave-assisted heating [ 31 , 32 , 33 , 34 , 35 ]. Microwave-assisted hydrothermal/solvothermal synthesis represents an attractive synthesis method when compared to conventional heating due to its high reaction rate, since microwave radiation is absorbed by the species present in the reaction medium, which results in a homogeneous and rapid volumetric heating [ 35 , 36 , 37 ].…”

Porous ZnO Nanostructures Synthesized by Microwave Hydrothermal Method for Energy Harvesting Applications

“…Despite all the established applications of ZnO, the research involving this semiconductor has not yet diminished, mostly due to the continuing development of new synthesis technologies and applications. For instance, ZnO nanomaterials can be easily synthesized into tailored sizes and morphologies at low temperatures (< 200 °C) by a variety of methods, including chemical bath deposition [38], electrodeposition [39], chemical vapor deposition [40], electrospinning [41], laser assisted flow deposition [42], and solvothermal [16] or hydrothermal [43,44] synthesis, either by conventional or microwave-assisted heating [4,45].…”