Controlled synthesis of ZnO nanoparticles from a Zn(II) coordination polymer: Structural characterization, optical properties and photocatalytic activity

Abstract

A zinc coordination polymer derived from pyridine‐2,6‐dicarboxylate (PDC), {[Zn2(PDC)2]}n, was successfully prepared via conventional, sonication and microwave‐irradiation methods. The composition and characteristics of the obtained coordination polymers (CPs) were investigated by elemental analysis, TGA/DTA, X‐ray diffraction and spectroscopic techniques. The so obtained CPs were heat‐treated in the air at 600 °C for 2 h to produce ZnO of nanosized particles (NPs). It is of interest to note that the synthesis approach of the precursor greatly affects both the nanoparticle size and the structure of the resulting ZnO NPs. Moreover, the smallest particle size was associated with the sample derived from the ultrasonically prepared precursor. TEM analysis revealed that all samples have sphere‐like morphologies. Structural analysis of the prepared ZnO samples was conducted and compared using Rietveld analysis of their PXRD patterns. Optical band gap calculations based on analysis of the UV–vis spectra of ZnO samples using Tauc's power law were achieved. The highest band gap of 3.63 eV was observed for ZnO sample obtained from the ultrasonically prepared precursor. Furthermore, the photocatalytic activity of ZnO NPs for the removal of Eosin Y color was monitored. The highest removal efficiency was recorded for ZnO originated from the ultrasonically synthesized precursor. Enhancement of removal efficiency that reached 98% was attained in only a period of 8 min. Its recycling test showed that it can be reused without structural changes over four cycling experiments.

Chemical‐ vs sonochemical‐assisted synthesis of ZnO nanoparticles from a new zinc complex for improvement of carotene biosynthesis fromRhodotorula toruloidesMH023518

“…Indeed, sonolysis is known of its ability for introducing disaggregation and reducing the size of the synthesized materials via introducing high pressure and temperature spots during synthesis in the reaction medium. [ 30–34,54–57 ] Additionally, it was confirmed that chemical and sonochemical synthetic routes for the complex formation resulted not only in coordination compounds of different sizes but also in obtaining derived NPs of different sizes. [ 30,58 ] The tetra‐coordinate zinc complexes especially those with salicylaldimine ligands are usually tetrahedral (SP 3 hybridization), and the involvement of salicylaldimine ligands in coordination was reported to be via the imine nitrogen and the hydroxyl oxygen atoms in a monobasic manner.…”

“…[ 30–34,54–57 ] Additionally, it was confirmed that chemical and sonochemical synthetic routes for the complex formation resulted not only in coordination compounds of different sizes but also in obtaining derived NPs of different sizes. [ 30,58 ] The tetra‐coordinate zinc complexes especially those with salicylaldimine ligands are usually tetrahedral (SP 3 hybridization), and the involvement of salicylaldimine ligands in coordination was reported to be via the imine nitrogen and the hydroxyl oxygen atoms in a monobasic manner. [ 59–61 ] The analytics only showed negligible differences between the nonsonicated and sonicated complex regarding the CHN composition, FT‐IR data and DMF solution electrical conductivity clearing the same formula of [ZnL 2 ] for the complex in both cases (Figure 1).…”

“…Preparation of the sonicated and nonsonicated ZnO NPs was based on heating the sonicated and nonsonicated [ZnL 2 ] in air at 600°C for 4 h. Sonochemical‐assisted techniques for synthesis are considered simple, fast, and ecofriendly that usually help in preparation of small sized NPs. [ 58 ] Interestingly, sonolysis as‐derived end products are usually of excellent purity and high surface area. [ 62,63 ] The powder X‐ray diffraction (PXRD) patterns of the nonsonicated and sonicated ZnO NPs (Figure 3) are not significantly different and all determined peaks were indexed in the ICDD file 04‐016‐6648 [ 64 ] clearing highest purity for the NPs: Both patterns displayed peaks attributed to the (100), (002), (101), (102), (110), (103), (200), (112), (201), (004), and (202) planes of hexagonal structure (space group: P6 3 mc), [ 64 ] whereas the diffraction peaks obtained from the nonsonicated ZnO NPs were intense and sharper than the peaks obtained from the sonicated ZnO NPs which is indicative for the size reduction in the sonicated sample.…”

“…[25][26][27][28][29] However, sonolysis is known to cause cavitation during synthesis of various products, as it affords formation, collapse, and growth of bubbles that result in introduction of high pressure and temperature spots affecting the size of the products. [30][31][32][33][34] In this research, we managed to prepare a new zinc complex of the ligand 2-(((3,4-dimethylphenyl)imino)methyl)phenol by two routes (chemical vs sonochemical) that both afforded different size ZnO NPs upon calcination. Subsequently, we studied the NPs' size effect on the biosynthesis of carotene by Rhodotorula toruloides MH023518.…”

Visible Light Driven Photodegradation of Pathological Effluents and Biological Evaluation of Green ZnO Nanoparticles

“…The negatively charged WGE ZnO NPs enable them to efficiently adsorb the cationic stains and facilitate electrochemical interactions between the reactive radicals and stain molecules. On irradiation with visible light, photons bearing energy greater than or equal to 2.72 eV will excite the electrons from the valence band to the conduction band generating electron‐hole pairs [64] . Holes produced in the valence band react with H 2 O or OH − to form hydroxyl radicals (OH⋅).…”