Synthesis of CNT and CNT-Cu composites

Abstract

 Nanostructured carbon materials feature unique properties and the expanding range of applications, so the research of methods for their synthesis is of high actuality. During the last years, even well-known CVD method of CNT synthesis was significantly modified and upgraded. In most of these advances, the uniformity of homogenous catalyst particles was concerned as the main goal. This paper presents results in the development of technological procedures for uniform deposition of catalysts from aqueous solutions of salts and electrodeposition with better CNT parameters.The water-soluble salts used were nickel nitrate and cobalt acetate. Degreased in organic solvents and cleaned with ultrasound the substrates were immersed in aqueous solutions of salts. Particles of metal oxides were formed while the sample was annealed in muffler at 400^оC in the air. Then CNT were synthesized in a quartz flow reactor in hydrogen at temperatures 650-700^оC in ethanol vapors. Raman spectra of so produced samples correspond to MWCNT. Ratios of ID/IG lines comprised 0.8-1.2. Electrodeposition of catalyst was used to improve the uniformity of CNT deposits. The deposition was from nickel nitrate solution with the addition of water-soluble polymer. One part of obtained samples was directly used for CNT synthesis. The second part was preheated at 400⁰С in the air. CNTs were synthesized at 650⁰С from ethanol vapor in 15 minutes. Revealed, that catalyst pre-heating in air leads to much more uniform CNT cover. At that, the quality of CNT is higher, such as ration ID/IG ~0.8. So the structural perfection is higher than in the case of a catalyst deposition from solution. Further electrolytic deposition of copper over CNT layer allowed obtaining CNT-Cu composite. SEM images show the morphology of so obtained composite as viewed from CNT side.

      G M T   Английский Испанский Итальянский Казахский Китайский Трад Китайский Упр Корейский Русский Турецкий Французский   Английский Испанский Итальянский Казахский Китайский Трад Китайский Упр Корейский Русский Турецкий Французский                 Звуковая функция ограничена 200 символами     Настройки : История : Обратная связь : Donate Закрыть