Synthesis of Al doped ZnO nanoparticles by aqueous coprecipitation

Abstract

International audienceAl-doped ZnO particles were obtained by a simple route: soda addition in aqueous cationic solution. The effects of temperature, hydrolysis duration, reagent concentration and time were investigated. A non-topotactic reaction mechanism, involving firstly the precipitation of various hydroxide compounds depending on the route (low or high pH), followed by the dissolution-recrystallization of the hydroxide species into ZnO was demonstrated. The Al concentration in the final ZnO nanopowders did not exceed 0.3 at.% which correspond to the solubility limit of Al in ZnO. The different experimental conditions allow the morphology of ZnO particles to be controlled from isotropic nanoparticles of several tens of nanometers, platelets of several hundreds of nanometers or agglomerates of needle like particles

Key role of terminal hydroxyl groups and visible light in the reactive adsorption/catalytic conversion of mustard gas surrogate on zinc (hydr)oxides

“…2). This mechanism is in agreement with results reporting the synthesis and transformation of ZnO by the decomposition of Zn(OH) 2 [2,3,6,19].…”

“…The obtained results follow the previous findings that different precipitates are formed by changing the mixing time and thus the pH gradient [4,6]. For both synthesis procedures, the initial ZnCl 2 /NaOH molar ratio was 0.5 and the initial pH of the precursor solution was 5.9 ± 0.2.…”

“…6A) show the well crystallized micrometric size particles of -Zn(OH) 2 with the rhombic octahedral shape of zinc hydroxide [4,6,24]. Platelets-like particles of similar sizes, which correspond to the zinc oxide phase, are also found on the SEM images in a limited quantity (Fig.…”

“…Thus, the precipitation/formation of ZnO or Zn(OH) 2 can be promoted by controlling the addition rate of the NaOH precipitant. It was found that the properties of precipitates formed from ZnCl 2 and a base depend on the pH of the solution and mixing time a slow addition of NaOH led to the formation of -Zn(OH) 2 [4,5], whereas a rapid addition yielded ZnO [6]. Nicholas et al reported that at temperatures less than 70 • C and using a NH 4 OH solution (0.03 M) as a precipitating agent, a würtzite growth from wülfingite was observed after a period of time.…”

Rapid, controllable, one‐pot and room‐temperature aqueous synthesis of ZnO:Cu nanoparticles by pulsed UV laser and its application for photocatalytic degradation of methyl orange

“…Among the metal oxide NPs, zinc oxide (ZnO) NPs are of special interest due to wide band gap, non‐toxicity, suitability for doping and their wide range of applications in electronic devices, luminescent materials, sensors, fuel cells, anti‐bacterial action and photocatalysts . A large number of methods are employed to synthesize ZnO NPs at various temperatures and reaction times, which include spray pyrolysis, sonochemical, hydrothermal/solvothermal, sol‐gel, combustion, laser ablation, pulsed laser deposition, ball milling, co‐precipitation and microwave assisted method . In many of them, the main aim is to reduce the cost of synthesis.…”