So, in this work, R6G was also used as the detection target for the study on the SERS property of silver-coated ZnO nanorod arrays.

The effect of heat treatment in hydrogen or air on the influence of SERS performance was investigated. The detection limit of R6G was also determined. Methods Sodium hydroxide and 2-methoxyethanol were obtained from Fluka (Fluka Chemical Corporation, St. Louis, Milwaukee, WI, USA). Zinc acetate and zinc nitrate were purchased from J.T. Baker Chemical Company (Phillipsburg, NJ, USA). Diethylenetriamine (DETA) was the product of Riedel-DeHaen (Honeywell International, Inc., Morristown, NJ, USA). Silver nitrate 99.9% was the product of Alfa Aesar (Ward Hill, MA, USA). Rhodamine 6G and monoethanolamine (MEA; 99.5%) was obtained selleck screening library from Sigma-Aldrich Corporation (St. Louis, MO, USA). The water used throughout this work was the reagent grade

water produced by a Milli-Q SP ultra-pure-water purification system of Nihon Millipore Ltd., Tokyo, Japan. ZnO nanorod arrays were prepared according to our previous work on the synthesis of Al-doped ZnO nanorod arrays but without Al doping [48, 49]. Firstly, 0.5 ml MEA was added to a solution learn more containing 11 ml 2-methoxyethanol and 1.8 g zinc acetate, which formed the ZnO sol–gel solution. ZnO seed layer was prepared by spin coating the sol–gel solution (0.1 ml) on a glass substrate (2.5 cm × 2.5 cm) at a rotation speed of 3,000 rpm for 30 s, and the films were then annealed at 350°C for 10 min. The step mentioned above was repeated eight times, and the acquired ZnO thin films were then annealed to 550°C for selleck inhibitor 2 h to get the final ZnO seed layer. Secondly, the ZnO seed layer was placed in an autoclave containing click here growth solution consisting of

30 ml water, 1.32 g zinc nitrate, 0.46 ml DETA, and 0.8 ml NaOH. After that, the growth solution was heated to 95°C for 6 h to get the ZnO nanorod arrays, which was noted as ZnO. The ZnO nanorod arrays were annealed in Ar/H2(97/3) or air atmosphere at 400°C for 2 h to get ZnO-H and ZnO-A, respectively. For the deposition of Ag nanoparticles on ZnO, ZnO-H, and ZnO-A, the resultant ZnO, ZnO-H, and ZnO-A were immersed in an aqueous solution of AgNO3 (5 ml, 0.01 M) and were illuminated under UV light (λ = 254 nm) for 10 min. This step was repeated three times to get ZnO@Ag, ZnO-H@Ag, and ZnO-A@Ag. For the investigation on the effect of Ag content on the photocatalytic activity of ZnO-H@Ag, the deposition step was conducted for 4 min × 1, 7 min × 1, 10 min × 1, 10 min × 2, 10 min × 3, or 10 min × 4 (here × denotes the repeating time).