Hydrothermal Synthesis and Structural, Morphological, and Optical Characterization of Flower-Like CoO

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Kızıltaş H.

6th International Conference on Advanced Engineering Technologies, Bayburt, Türkiye, 23 Eylül - 25 Ekim 2026, ss.1541-1545, (Tam Metin Bildiri)

  • Yayın Türü: Bildiri / Tam Metin Bildiri
  • Basıldığı Şehir: Bayburt
  • Basıldığı Ülke: Türkiye
  • Sayfa Sayıları: ss.1541-1545
  • Atatürk Üniversitesi Adresli: Evet

Özet

Cobalt(II) oxide (CoO) is a transition-metal oxide semiconductor with attractive structural and optical properties for applications in photocatalysis, electrochemical energy conversion, and related functional materials. In this study, three-dimensional flower-like CoO structures were synthesized through a hydrothermal route and systematically characterized in terms of their morphological, elemental, structural, vibrational, and optical properties. The precursor solution containing Co(NO3)2·6H2O, urea, and NH4F was hydrothermally treated at 110 °C for 6 h, followed by drying and calcination at 300 °C for 2 h. Scanning electron microscopy (SEM) revealed the formation of well-defined three-dimensional flower-like architectures with an average diameter of approximately 6 μm, while energydispersive X-ray spectroscopy (EDS) confirmed the presence of Co and O in the synthesized material. X-ray diffraction (XRD) analysis exhibited characteristic reflections at 2θ values of approximately 36.4°, 42.3°, 61.4°, 73.6°, and 77.5°, which were indexed to the (111), (200), (220), (311), and (222) planes of cubic CoO, respectively, in agreement with JCPDS No. 48-1719. Fourier-transform infrared spectroscopy (FTIR) further supported the formation of the metal oxide structure and revealed surface hydroxyl-related vibrations. The optical properties were evaluated using UV–Vis spectroscopy and the Tauc approach, yielding an optical band-gap energy of approximately 2.78 eV. The combined characterization results demonstrate that the hydrothermal route followed by moderate-temperature calcination provides an effective approach for producing crystalline flower-like CoO structures with distinctive morphological and optical characteristics.