Alignment, Morphology and Defect Control of Vertically Aligned ZnO Nanorod Array: Competition between “Surfactant” and “Stabilizer” Roles of the Amine Species and Its Photocatalytic Properties

Abstract

We show that the morphology, AbstractWe show that the morphology, defect and alignment of vertically aligned one dimensional ( 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 2 amine concentrations, the role as surfactant dominates over that of stabilizer which does not favor uniform growth due to the slow release of Zn to form ZnO. On increasing the amine concentration, Zn release and amine capping aspects were balanced and this result in uniform and aligned growth of NR arrays. At the higher amine concentrations, the sudden release of Zn generates an overshoot effect, which dominates over the surfactant capping aspect, thus favoring the growth of irregular micro platelets. 1D, well aligned, prismatic, ZnO NR arrays grown at an amine concentration of 1Mshow higher photocatalytic degradation activity for the degradation of Methylene Blue dye solution under UV irradiation owing to both the high surface to volume ratio of the arrays and increased charge carrier density due to Zn interstitial defects. Zinc interstitials are shallow donors readily supply electrons to conduction band which could buildup space charge near to the nanocatalayst surface. The occurrence of band bending associated with the interfacial electric field in the space charge region could facilitate the separation of photogenerated electrons and holes and thus enhances the photocatalytic performance. Understanding the role of amine in the growth of 1D ZnO NR arrays holds great promise for tailoring ZnO NR functionalities for various potential applications

Controlled Growth of Supported ZnO Inverted Nanopyramids with Downward Pointing Tips

“…18,23 Nevertheless, supported systems stand as a more attractive choice for functional applications, thanks to the lower tendency to sintering and/or deactivation and to the possibility of being directly integrated into functional devices. 4,[51][52] In this work, we report on the successful fabrication of ZnO nanopyramids with downward pointing tips without the use of any seed/buffer/catalyst layer, at variance with previous reports on the growth of ZnO nanomaterials. 4,6,27,[53][54]57 The target pyramids have been obtained by a simple one-step chemical vapor deposition (CVD) route, which, beside the scalable advantages due to its industrial character, enables a high control on the purity, crystallinity and morphology of the resulting ZnO nanostructures.…”

Robust water repellent ZnO nanorod array by Swift Heavy Ion Irradiation: Effect of Electronic Excitation Induced Local Chemical State Modification

“…Dip coating process was repeated three to four times and the substrate was annealed at 350 °C. The ZnO seed layer coated substrate was immersed into a solution of equal mole of Zinc nitrate hexahydrate and Hexamine (HMTA) (C 6 H 12 N 4 ) which were used as the precursors 45 . After immersing the substrate by facing top down, growth solution was maintained at 97 °C for 4 hours.…”

Multifunctional ZnO nanorod-reduced graphene oxide hybrids nanocomposites for effective water remediation: Effective sunlight driven degradation of organic dyes and rapid heavy metal adsorption

“…Graphene oxide (GO) was synthesized from natural graphite flakes by a modified Hummers method [16]. The 1D ZnO NRs were synthesised through the aqueous solution using equal mole of (0.125 mM) Zn(NO 3 ) 2 Á6H 2 O and HMTA [17]. The clear experimental procedures for synthesis of GO and ZnO NRs were given in supporting information part.…”