Short communicationSimple synthesis of ZnO nanoflowers and its photocatalytic performances toward the photodegradation of metamitron
Graphical abstract
Introduction
Due to the increasing contamination of organic pollutants to the environment, extensive research efforts have been concentrated on the photocatalytic technology for their treatment [1], [2]. Recently, some new class of materials with enhanced photocatalytic activity have been designed and efficiently synthesized through simple solvothermal method [3], [4], [5], [6], [7], [8]. For example, Ti-doped BrOBr with Ag decoration microsphere, and Fe-doped BrOBr hollow microsphere materials featured excellent photocatalytic activity towards the degradation of Rhodamine B [3], [4]. The Zn2GeO4/CFs (carbon fibers) composites exhibited good photocatalytic activity for the oxidation of p-toluidine [6].
The agrochemical of metribuzin and metamitron, derived from the structure of 4-amino-1,2,4-triazin-5(4H)-one, have been widely used as herbicides. They are chemically stable and can slowly penetrate through the soil and cause the severe contamination of underground resources of drinking water. The traditional semiconductor catalysts such as TiO2, and ZnO have been frequently used for the degradation of organic pollutants owing to their advantages of low cost, high photocatalytic activity and photostability. Zinc oxide (ZnO), a widely known important n-type semiconductor with a wide-band-gap of 3.37 eV, has been receiving broad attention due to its distinguished performance in optoelectronics, catalysis, chemical sensors and transducers [9], [10], [11]. In the past years, various approaches like sonochemical route [12], thermal evaporation [13], chemical precipitation method [14], microwave hydrothermal [15], employ ionic liquids, and hydrothermal method [16] have been developed to synthesize ZnO nanostructures with various morphologies, including nanoflowers [17], nanowires [18], nanobelts [19], nanorods [20], and nanotubes [21] and so on. Among them, three-dimensional (3D) nanostructures are of great interest to scientists owing to their novel architectural nanostructures may provide good performance in photocatalysis and photoluminescence. Especially, hierarchical 3D ZnO nanostructures with excellent photocatalytic activity, and diverse properties for more potential applications are strongly expected to be prepared through an economical method.
In our work, a hierarchical ZnO nanoflowers assembled from numerous nanosheets has been successfully synthesized through a facile, eco-friendly and one-step hydrothermal synthesis method using zinc acetate, sodium citrate, and sodium hydroxide in the water solution. The products possess remarkable photocatalytic acitivity and excellent cycle stability for the degradation of metamitron in aqueous solution under a 300 W of Osram® lamp light emitting UV and visible radiation over 300–600 nm. The promising mechanism of photocatalysis of metamitron is also provided.
Section snippets
Materials
The analytical reagents include zinc acetate (C4H6O4Zn·2H2O, 99.9%, Guangfu, Tianjin, China), sodium citrate (C6H5O7Na3·H2O, 99.0%, Yongda, Tianjin, China), sodium hydroxide (NaOH, 99.5%, Guoyao, Shanghai, China, http://www.sinoreagent.com), metamitron (C10H10N4O, 97%, Aldrich, Shanghai, China) and pure water (commercial “Wahaha” purified drinking water, China). All of the chemical reagents are used without further purification.
Synthesis
The ZnO nanoflowers were prepared by a one-step hydrothermal
Structure and morphology
The phase of the products was characterized by XRD. As shown in Fig. 1, in the XRD pattern of as-prepared hierarchical ZnO nanoflowers (Fig. 1a), the peaks observed at 2θ = 30.1°, 35.5°, 43.2°, 53.6°, 57.0° and 62.7° correspond well to the stimulated XRD pattern of hexagonal wurtzite crystal structure of ZnO (JCPDS 36-1451) (Fig. 1b), indicating that no other impurities are found in the products. The morphologies of the hierarchical ZnO structure obtained was investigated by SEM. Fig. 2a and 2b
Conclusion
We report a simple and eco-friendly one-step hydrothermal route method for the preparation of hierarchical ZnO nanostructure, and its remarkable photocatalytic acitivity toward metamitron in aqueous solution under a 300 W of Osram® lamp light (300–600 nm), as well as its excellent cycle stability in the reutilization experiment. It revealed that about 97% of the metamitron disappeared in the suspension of the flower-like ZnO microspheres within four hours, and the degradation efficiency were
Acknowledgements
This work was supported by the National Natural Science Foundation of China (Grant No. 21401018) and the Fundamental Research Funds for the Central Universities (No. N130305003).
References (26)
- et al.
Mater. Res. Bull.
(2015) - et al.
Mater. Res. Bull.
(2015) - et al.
Thin Solid Films
(2009) - et al.
Mater. Lett.
(2012) - et al.
Appl. Surf. Sci.
(2013) - et al.
Mater. Lett.
(2009) - et al.
Mater. Res. Bull.
(2008) - et al.
J. Colloid Interface Sci.
(2009) J. Phys. Chem. Solids
(1960)- et al.
Chemosphere
(1997)
Chem. Soc. Rev.
Adv. Mater.
ACS Appl. Mater. Interfaces
Cited by (45)
Metalloporphyrin/ZnO solids as selective catalysts for oxidation reaction assisted by light
2023, Applied Catalysis A: GeneralPhotocatalytic degradation of triazine-based pesticides
2023, Advanced Functional Materials and Methods for Photodegradation of Toxic PollutantsFluorometric biosensor based on boronic acid-functionalized ZnO-derived nanostructures for the detection of N-acetylneuraminic acid and its in vivo bio-imaging studies
2022, Journal of the Taiwan Institute of Chemical Engineers