Synthesis and Growth Mechanism of Cu Nanowires in the Presence of Different Linear Alkyl Diamines

Growth and Characterization of Ni Nano-Micro Structures in the Presence of Ethylenediamine

“…When 3 mL EDA was used in the synthesis, all the peaks observed in the XRD patterns can be indexed to Ni with an fcc structure, indicating that the microspheres observed in Figure 1f are Ni microspheres. These observations indicate that under our experimental conditions, Ni(II) is difficult to be reduced to Ni in the absence of EDA and the addition of EDA favors the reduction of Ni(II) to Ni, which is different from the observation in the reduction of Cu(II) to Cu [11]. Actually, we have tried to reduce Ni(II) to Ni in the absence of EDA by raising the reaction time to 8 h. However, XRD measurement suggests that the product is still in the form of Ni(OH) 2 (Figure 2a), and no microflowers or microspheres can be found in the product (Figure 2b).…”

“…The high resolution TEM image of the tip of this nanohorn is shown in Figure 5f. The reduced fast Fourier transform (FFT) image of the framed region (inset of Figure 5f) suggests that the nanohorn grows along the <1-10> direction, which is similar to the growth feature of Cu nanowires [11] or Cu nanocusps [29] under similar experimental conditions. In the growth of Cu nanowires [11] or Cu nanocusps [29], one of the roles of diamine is to induce an orientated growth, namely acting as capping agent.…”

“…In our early studies [11,29], we have found that the addition of EDA in concentrated alkaline solution not only changes the morphology of as-formed Cu products [11,29], but also influences the reduction of Cu(II) to Cu [11]. To determine whether similar phenomenon can be observed in the growth of Ni, we first examined the effect of the amount of EDA on the morphology and phase composition of the resulting product.…”

“…Amines, a class of organic compounds, which contain an amino group with a pair of lone electrons on the nitrogen atom, are widely used for mediating the growth of a variety of nanostructures, including nanocrystals, nanosheets, nanorods, and nanowires [1][2][3][4][5][6][7][8][9][10][11][12][13][14]. As the simplest diamine after hydrazine, for example, ethylenediamine (EDA) can be used as a capping agent in the synthesis of ultrasmall CeO 2 particles [5], PbS nanosheets [6], Mn 3 O 4 nano-octahedrons [7], and CdS multipods [8], as a coordination template in the synthesis of CdX (X = S, Se, Te) nanorods [9] and ZnS nanowires [10], and as both capping agent and complexing agent in the growth of Cu nanowires [11,12]. In addition, EDA has also been employed in the synthesis of microsized materials [15][16][17].…”

“…In this work, we present a study on the EDA-mediated synthesis of Ni nano-micro structures, namely microflowers or microspheres assembled from nanosized horns, via a solution reduction route in concentrated alkaline solution. Unlike the synthesis of Ni nanostructures or nano-micro nanostructures in an alkaline solution of low concentration in the presence of polyvinyl pyrrolidone, cetyltrimethylammonium bromide, or potassium sodium tartrate [25][26][27][28], the use of EDA in high concentrated alkaline solution is inspired by our previous work on the synthesis of Cu nanowires [11] and hierarchical Cu structures [29]. The present work mainly focuses on two aspects: (i) The effect of both EDA and NaOH on the reduction of Ni(II) to Ni and the morphology of the resulting Ni products, and (ii) the growth mechanism of these Ni nano-micro structures.…”