Formation of ZnO Nanorods via Seeded Growth Hydrothermal Reaction

Abstract

In this study, ZnO nanorods was formed on a seeded substrates prepared by thermal oxidation of Zn foil followed by hydrothermal reaction. ZnO seed was prepared via thermal oxidation process at 300°C for 10 minutes to form uniform circular nanosize grains that were suitable as a seeded template for the growth of ZnO nanorods via hydrothermal reaction. Several hydrothermal reaction parameters were studied; hydrothermal reaction temperature, ratio of zinc nitrate to hexamethylamine and pH. In hydrothermal reaction, the formation of ZnO nanorods occurs due to thermal degradation of hexamethylamine (HMT) which released hydroxyl ions that react with Zn ions in the precursor solution. Well aligned, ZnO nanorods with length of ~700 nm, base diameter of ~200 nm and top diameter of less than 30 nm needle-like structure were formed on seeded Zn substrate with concentration ratio of zinc nitrate to hexamethylamine 0.1M:0.1M, pH 6-7 at hydrothermal reaction temperature of 80°C

Structural and Morphology of ZnO Nanorods Synthesized Using ZnO Seeded Growth Hydrothermal Method and Its Properties as UV Sensing

“…Given that the ZnO growth rate is preferentially high at the c-axis, ZnO recrystallization causes growth on the [0001] plane. Thus, thinner and longer ZnO nanorods are produced with increased growth duration [5].…”

“…Seeded substrates are used in the hydrothermal technique to achieve well-controlled morphology and growth direction of ZnO nanorods. Heterogeneous nucleation favors the growth of ZnO nanorods because the interfacial energy between crystals and substrate is usually smaller than the interfacial energy between crystals and solution [5]. Therefore, pre-coating the substrate with seed materials similar to nanocrystals can effectively control nanorods growth and morphology.…”

Dissolution–recrystallization and regrowth mechanism of hydrothermally derived six faceted prismatic hexagonal ZnO microrods

“…It was reported that the ZnO growth rate is preferentially high along the c-axis, that is why ZnO recrystallization causes growth on the [0 0 0 1] plane. Thus, thinner and longer ZnO nanorods are produced with increased growth duration [32]. (c) The core of flowerlike morphology was poorly crystallized and easily dissolves into ZnO aggregate during prolonged reaction time.…”

PENGARUH WAKTU AGING PADA SINTESIS SENYAWA ZnO:GO SEBAGAI MATERIAL AKTIF FOTOKATALIS

“…Sintesis nanopartikel ZnO sebagai fotokatalis dengan metode yang berbeda dapat menghasilkan karakteristik yang berbeda pula, beberapa metode yang dapat dilakukan diantaranya evaporasi termal, molecular beam epitaxy (MBE), deposisi elektrokimia, spray pyrolysis, dan metode sol-gel [11]. Metode sol-gel merupakan metode yang relatif sederhana, mudah, dan murah diantara metode lainnya [12].…”

“…Sintesis nanopartikel ZnO sebagai fotokatalis dapat dilakukan dengan berbagai metode, namun proses sol-gel relatif lebih sederhana, biaya produksi rendah, dan dapat menghasilkan partikel berukuran nano pada suhu rendah [11,13]. Metode sol-gel terbagi menjadi enam tahapan, yakni proses hidrolisis dan kondensasi (sol terbentuk), kondensasi lanjutan (gel terbentuk), ageing process (endapan terbentuk), drying process (xerogel terbentuk), dan proses pembentukan xerogel menjadi fasa yang diinginkan [13].…”