Solution growth of ZnO sub-micro rods enhanced by electric field

Abstract

Abstract.Recently the one-dimensional ZnO nanostructures have attracted much attention in gas sensor applications owing to their increased role of the surface. The authors have obtained ZnO rods of sub-micron size using the solution growth method with the growth temperature below 100• C. Investigations indicate that the rods have a well-defined hexagonal morphology and a wurtzite structure. The best uniformity and alignment of the sub-micron crystals was however obtained when electrodeposition from aqueous solution was developed. Sizes of these rods depend on the growth parameters. Moreover electrodeposition leads to a faster growth rate of ZnO sub-micron rods (2 hrs) as compared to the growth from solution (8 hrs). After electrodeposition the rods can be easily reoriented in external electric fields by using substrates with electrodes of appropriate geometry and configuration (dielectrophoretic effect). This enables the preparation of samples which can be used in gas sensor technology.

Metal oxide nanostructures for gas detection

“…The diameters of fabricated structures vary between 300 and 500 nm with the length reaching 20 μm. The XRD patterns of the ZnO nanostructures obtained for successive methods do not differ essentially from the pattern of ZnO reference powder [18]. Although ZnO nanostructures obtained with methods I-III potentially could be used in further tests as a gas sensitive layers/structures, they exhibited a very high resistance and the measurements were sometimes troublesome due to poor contact between the nanorods.…”

“…The obtained nanorods could be easily reoriented by external electric fields using electrodes with appropriate configuration and a.c. voltages of adequate magnitude and frequency. Details of a.m. methods are described in [18]. By applying methods I and II the bunches of sub-micro rods were obtained, Fig.…”

GLAD Magnetron Sputtered Ultra-Thin Copper Oxide Films for Gas-Sensing Application

“…Generally, a gas sensor consists of gas-sensitive films and gas sensor substrate with electrodes, a package, and front-end electronic circuits. The gas-sensitive layer can be realized based on various materials, including organic compounds (e.g., phthalocyanines [2,3]) and metal oxides [4] (e.g., WO 3 [5,6], TiO 2 [7,8], SnO 2 [9,10], In 2 O 3 [11,12], Fe 2 O 3 [13,14], MoO 3 [13,15], ZnO [16][17][18], CuO [19][20][21][22][23][24][25][26][27][28]). The most common methods for metal oxide depositions are magnetron sputtering [29,30], sol-gel [31,32], thermal oxidation [33,34], hydrothermal techniques [35,36], the spray pyrolysis technique [37,38], and the microwave-assisted method [39,40].…”

Sensor properties of ZnO:Al nanofibres obtained by electrospinning

“…Growing of nanostructured ZnO can be accomplished by adopting a number of techniques [6,7]. Among them the electrospinning provides a simple, straightforward way to fabricate one-dimensional materials with easy control and low cost [8][9][10].…”