Sonochemical Synthesis of 0D, 1D, and 2D Zinc Oxide Nanostructures in Ionic Liquids and Their Photocatalytic Activity

Abstract

Ultrasound synthesis of zinc oxide from zinc acetate and sodium hydroxide in ionic liquids (ILs) is a fast, facile, and effective, yet highly morphology- and size-selective route to zinc oxide nanostructures of various dimensionalities. No additional organic solvents, water, surfactants, or templating agents are required. Depending on the synthetic conditions, the selective manufacturing of 0D, 1D, and 2D ZnO nanostructures is possible: Whereas the formation of rodlike structures is typically favored, ZnO nanoparticles can be obtained either under strongly basic conditions or by use of ILs with a long alkyl chain, such as 1-n-alkyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide ([C(n)mim][Tf(2)N]; n>8). A short ultrasound irradiation time favors the formation of ZnO nanosheets. Prolonged irradiation leads to the conversion of the ZnO nanosheets into nanorods. In contrast, ionothermal synthesis (conventional heating) does not allow for morphology tuning by variation of the IL or other synthesis conditions, as the longer reaction times required lead always to the formation of well-developed hexagonal nanocrystals with prismatic tips. The ZnO nanostructures synthesized by using ultrasound were efficient photocatalysts in the photodegradation of methyl orange. The photoactivity was observed to be as high as 95 % for ZnO nanoparticles obtained in [C(10)mim][Tf(2)N].

Tuning the Crystal Phase and Morphology of the Photoluminescent Indium Sulphide Nanocrystals and Their Adsorption‐Based Catalytic and Photocatalytic Applications

“…To illustrate the effect of sulphur concentration and reaction time on the band gap of as‐obtained In 2 S 3 and In 2 S 3 /In(OH) 3 nanoparticles, absorbance spectra were measured using the UV‐vis diffuse reflectance spectrophotometer (Figure (a) and S7). The graph is plotted between (abs*hν (eV)) 2 vs hν(eV) ,. By this, band gap was appeared within the range of 2.16 ‐ 2.87 eV corresponds to the absorption edge excitation (Figure (b) and S8).…”

Enhanced Red Emission in Ultrasound‐Assisted Sol‐Gel Derived ZnO/PMMA Nanocomposite

“…In line with X-ray analysis that ZnO NPs had crystalline domains of 29 ÷ 45 nm, the TEM image of a ZnO particle shown in Figure 2(d) reveals many connecting ZnO domains within one particle. e extreme reaction conditions, for example, high temperatures, pressure, and heating and cooling rates, induced by collapse of microbubbles in ultrasound irradiated solution have been utilized to prepare various ZnO nanostructures [8,21,22]. Ultrasonication conditions (intensity, duration, temperature, and duty cycle) and chemical composition (solvent and additives) are proposed to be the key parameters of controlling over the morphology of ZnO nanostructures.…”

Metal oxide and bimetallic nanoparticles in ionic liquids: synthesis and application in multiphase catalysis

“…Alammar and Mudring also recently reported the importance of the nature of the IL used and the exact reaction conditions on the resulting particle size and morphology of ZnO nanomaterials [67] . Using their established ultrasound synthesis in neat ILs, several parameters were varied, each time ensuring that other reaction variables were kept constant.…”