Continuous synthesis of photocatalytic nanoparticles of pure ZnO and ZnO modified with metal nanoparticles

Abstract

The continuous microwave synthesis of ZnO, ZnO–nAg and ZnO–nCu nanoparticles (NPs) are presented. Initially, pure ZnO nanoparticles were synthesised, studying the effect of selected parameters on the size of crystallites. In the second stage, ZnO nanoparticles modified with metal nanoparticles were obtained by conducting the process in a flow system. Tannic acid was used as a reducing agent of silver and copper ions. The structure, crystallinity and effectiveness of the deposition of metal nanoparticles were assessed by XRD, XPS, FTIR and electron microscopy techniques (SEM and TEM). The obtained materials were tested for their photocatalytic properties against methylene blue in UV light. The results of photodegradation in ultraviolet light have shown that the introduction of metal nanoparticles, especially silver nanoparticles, significantly increases catalytic efficiency (30% for pure ZnO NPs, 91% for ZnO–nAg NPs and 54% for ZnO–nCu NPs). The main advantage of the proposed ZnO/Ag semiconductor is that it delays the recombination process of electron–hole pairs generated by photon absorption, which extends the efficiency of such a photocatalyst. Based on the research, we determined that it is possible to use photocatalytically active ZnO modified with metal nanoparticles obtained in the flow process. Graphic abstract

Enhanced Photocatalytic Degradation of Methylene Blue Using Ti-Doped ZnO Nanoparticles Synthesized by Rapid Combustion

“…The XRD patterns of ZnO and Ti-ZnO in Figure 5 show the diffraction angles at 2θ of 31.7°, 34.5°, 36.2°, 47.5°, 56.6°, 62.9°, and 68.0° indexed to the crystal planes of (100), (002), (101), (102), (110), (103), and (122), respectively [ 22 , 25 ]. The patterns corresponded well with the hexagonal wurtzite structure of ZnO, according to the standard JCPDS no.…”

Two-step strategy, growth mechanism and optical properties of plasmonic Ag-modified ZnO nanomaterials

“…32 So far, Ag/ZnO nanomaterials prepared using different methods have been investigated by many researchers. [22][23][24][25][26][27] For example, Ag-modied ZnO (AZO) nanostructures have been synthesized using hydrothermal (HT) and chemical vapor phase (CVD) methods, 28 cryogenic methods, 29 wet chemical synthesis and thermal evaporation, 30 among other methods and techniques. For example, Ievtushenko et al 22 obtained the Ag decorated ZnO nanorods on a silicon substrate using the CVD method and reported the surface morphology and near-band edge emission of the samples.…”

“…Wang et al 23 successfully synthesized Ag nanoparticles decorated 3D ower like Zn. O. Długosz et al 24 synthesized ZnO-Ag NPs using the continuous microwave method and studied the structure, crystallinity and photocatalytic properties of the sample modied with metallic Ag. In previous studies by our group, AZO nanowires (NWs) and nanoowers (NFw) were synthesized using a two-step CVD composite magnetron sputtering (MS) method and a two-step HT composite MS method, 34,35 respectively.…”

PHOTOCATALYST ACTIVITY OF MgO FROM BANGKALAN DOLOMITE

“…The use of metal oxides as photocatalytic has also shown promising potential for various environmental applications, including mineralization of various organic pollutants, water disinfection, and gas sensing of wastewater [9]. TiO2, ZnO, WO3, Fe2O3, and CuO are metal oxides that have been extensively investigated and can be used as photocatalytic materials to decompose organic pollutants in the air, soil, and water [10][11][12][13][14][15][16][17].…”