Water–Organic Cosolvent Effect on Nucleation of Solution-Synthesized ZnO Nanowires

Abstract

Here, we show the effect of water–organic (acetone, tert -butyl alcohol, and isopropanol) cosolvents on nucleation and anisotropic crystal growth of solution-synthesized ZnO nanowires. The addition of organic solution does not alter the face-selective crystal growth nature but significantly promotes the crystal growth of both length and diameter of the nanowires. Systematic investigations reveal that a variation of the relative dielectric constant in the cosolvent can rigorously explain the observed effect of the water–organic cosolvent on the ZnO nanowire growth via the degree of supersaturation for the nucleation. The difference between acetone, tert -butyl alcohol, and isopropanol on the cosolvent effect can be interpreted in terms of a local solvent-sorting effect.

Synthesis of Monodispersedly Sized ZnO Nanowires from Randomly Sized Seeds

“…In order to synthesize such monodisperse metal oxide nanowires, most fundamental research has been devoted to understand the principles of nanowire growth using various techniques, including vapor-phase − and solution-phase synthesis. − Many studies consistently showed the crucial importance of a homogeneously sized initial nucleation to obtain the monodisperse nanowires. For controlling the initial nucleation, a seed prepatterning approach on substrate that defines the seed size has been demonstrated via different lithographic techniques. − ,, However, these techniques are very costly and restricted to operation in limited areas.…”

Face-selective tungstate ions drive zinc oxide nanowire growth direction and dopant incorporation

“…To understand the contribution of WO 4 2− ions for the nucleation phenomenon, next we examine the Zn precursor concentration dependence on ZnO nanowire growth with various C W . Previous our study demonstrated that there exist two threshold concentrations corresponding to the critical concentrations for nucleation on (0001) plane and 10 10 ð Þ plane [22][23][24] . By evaluating the shifts of critical concentrations with varying C W , the influence of WO 4 2− ions for the nucleation events on ZnO crystal planes can be identified.…”

“…In principle, there are two possible approaches for modulating the dopant incorporation, i.e., a control of W precursor concentration and a control of dopant adsorption on nanowire surface. On the other hand, the morphology can be manipulated by controlling C Zn according to the critical concentration for nucleation on ZnO crystal planes, which is so-called as "concentration window" principle [22][23][24] . However, as shown in Fig.…”

“…Therefore, most of previous researches have been devoted to establish predictable models and strategies for controlling the morphology of nanomaterials. As for the hydrothermally synthesized zinc oxide (ZnO) nanowires, the strategies based on the electrostatic interaction between metal ions and crystals 19 , the organic ligand based surface capping 20 , the ligandexchange effect 21 , and the difference in critical nucleation concentrations on crystal planes so-called "concentration window" [22][23][24] have been demonstrated and successfully manipulated the nanowire morphology.…”

The impact of surface Cu2+ of ZnO/(Cu1−xZnx)O heterostructured nanowires on the adsorption and chemical transformation of carbonyl compounds

“…ZnO nanowires were grown on a 100 nm thick SiO 2 coated Si (100) substrate by hydrothermal synthesis [36][37][38][39][40][41]. A 5 nm thick Ti buffer layer and a 100 nm thick ZnO lm were sequentially deposited on the substrate by radio frequency (RF) sputtering at a RF power of 50 W and an Ar pressure of 0.3 Pa.…”