pH dependent ZnO nanostructures synthesized by hydrothermal approach and surface sensitivity of their photoelectrochemical behavior

Abstract

Nanoparticulate ZnO materials were fabricated using microwave assisted hydrothermal synthesis from mixture of zinc acetate and ammonia at variable pH. The particle size and shape of resulting materials changes with the pH of precursor solution. The obtained nanoparticulate ZnO are of single phase nature with particle size ranging between 100 and 3000 nm, and are photoelectrochemically active in water oxidation upon UV illumination. Their photoelectrochemical activity, depends primarily on the ZnO particle surface orientation which changes with the particle size. The highest photoelectrochemical activity results from simultaneous presence of {0− 110} and {− 2110} oriented faces. The presence of {0001} oriented faces apparently suppresses the photoelectrochemical activity. The results indicate that the photoelectrochemical activity of ZnO is mainly related to a presence of {0−110} oriented surface.

Antibacterial and Photocatalytic Properties of ZnO Nanoparticles Obtained from Chemical versus Saponaria officinalis Extract-Mediated Synthesis

“…The similar optical behavior of all samples, with close values of bandgap energy regardless of the differences in particle size, was reported previously for ZnO nanomaterials with dimensions larger than Debye length in ZnO [50].…”

Photo(electro)catalytic Performance of ZnO‐Based Nanopowders Prepared through Pulse Alternating Current Electrosynthesis in Alkaline Earth Chloride Electrolytes

“…Earlier reports describe a crucial impact of the crystallinity and particle size on the photoelectrochemical response of semiconducting materials which can be controlled by means of thermal treatment [25] or pH change during synthesis [26] …”

“…Earlier reports describe a crucial impact of the crystallinity and particle size on the photoelectrochemical response of semiconducting materials which can be controlled by means of thermal treatment [25] or pH change during synthesis. [26] XRD patterns acquired from ZnO synthesized in BaCl 2 aqueous solution and thermally treated at 300 °C, 400 °C, 500 °C or 600 °C were used to determine average crystallite size (Figure 3a). As expected, increasing the thermal treatment temperature from 400 °C to 600 °C results in increasing crystallite size from 25.4 to 48.5 nm.…”

Reverse strain effects in the defect states in aluminium doped ZnO

“…Colloidal Ag-ZnO has also been synthesised. There are numerous similar procedures of metal-ZnO synthesis [20][21][22][23][24][25][26][27][28]. We synthesised Al-doped ZnO NPs through the sol-gel method using a mixture of zinc nitrate hexahydrate (Zn(NO 3 ) 2 •6H 2 O), aluminium nitrate nonahydrate (Al(NO 3 ) 3 •9H 2 O), urea CH 4 N 2 O, ethanol, and DI (Deionized) water.…”