Catalysis and Temperature Dependence on the Formation of ZnO Nanoparticles and of Zinc Acetate Derivatives Prepared by the Sol−Gel Route

Abstract

The chemical and structural nature of powders prepared from the zinc acetate-derived precursor using the sol−gel route is discussed. The influence of the synthesis temperature and of the hydrolytic catalyst on the structural features of the powder is focused on the basis of X-ray powder diffraction (XRPD) and extended X-ray absorption fine structure (EXAFS) measurements and complemented with density and thermoanalysis (TG-DTA) results. EXAFS and XRPD results show that no-washed nanoparticulate powders are composed of a mixture of ZnO (wurtzite), zinc acetate, and zinc hydroxyacetate. The latter has a layered structure typical of hydroxy double salts (HDS). The main component of no-washed powders is always unreacted zinc acetate solid but the relative amount of the zinc-based compounds depends on the nature of the hydrolytic catalyst, hydrolysis ratio, and of synthesis temperature. According to the proportion of the three zinc-based compounds, three families of powders could be distinguished. The amount of ZnO nanoparticles (1.6 ± 0.6 nm) decreases as the synthesis temperature increases, as the hydrolysis ratio decreases, or by changing from basic to acid catalysis. This finding suggests that the formation of zinc compounds is controlled by the equilibrium between hydrolysis−condensation and complexation−reprecipitation reactions.

Synthesis of Colloidal Mn2+: ZnO Quantum Dots and High‐Tc Ferromagnetic Nanocrystalline Thin Films.

“…39 The precursors for ZnO nucleation under these conditions are believed to be basic zinc acetate clusters. 35,40 After 0.45 equiv, subsequent base addition causes further nucleation of ZnO and a stoichiometric increase in band gap absorption intensity is observed (Figure 1). …”

Cobalt and nickel nanoparticles fabricated p(NIPAM-co-MAA) microgels for catalytic applications

“…The catalytic applications of nanoparticles of expensive metals such as gold (1,12), silver (2,3,13), platinum (14)(15)(16) and palladium (17)(18)(19)(20) are mostly studied because they are stable under different environmental conditions and do not oxidize to their oxides easily. Contrary to this, there are some coinage metal-based nanoparticles [such as zinc (21), copper (22,23), nickel (Ni) (24) and cobalt (Co) (25) whose catalytic applications have not been enormously studied so far, because they are less stable. These metals and their salts are less expensive than silver and gold; thus we are going to report on the catalytic applications of the nanoparticles of these metals.…”

A novel zinc(II) macrocycle-based synthesis of pure ZnO nanoparticles

“…ZnO nanoparticles have a wide range of applications such as gas sensors [6], dye-sensitized solar cells [7], ultra violet photodetectors [8], UV lasers [9], photocatalysts [10], piezoelectric transducers [11], and for biomedical applications [12]. They have been synthesized by various methods such as chemical vapor deposition [13], sol-gel method [14], low-temperature wet chemical methods [15], electrochemical deposition [16], laser ablation [17], pulsed laser deposition [18], thermal decomposition [19], spray pyrolysis [20], radiofrequency magnetron sputtering [21], and hydrothermal method [22]. The main purpose of each method is to prevent the crystallite agglomeration, control the particle shape, size, and crystal phase of ZnO nanoparticles.…”