Structural- and optical-properties analysis of single crystalline hematite (α-FeO) nanocubes prepared by one-pot hydrothermal approach

• Published in: CrystEngComm 2016-01, Vol.18 (25), p.472-4732
• Main Authors: Abdul Rashid, Nur Maisarah, Haw, Choonyian, Chiu, Weesiong, Khanis, Noor Hamizah, Rohaizad, Aliff, Khiew, PoiSim, Abdul Rahman, Saadah
• Format: Article
• Language: English
• ISSN: 1466-8033; 1466-8033
• DOI: 10.1039/c6ce00573j

High quality single crystal hematite (α-Fe 2 O 3 ) nanocubes with average dimensions of 40 nm were successfully synthesized by a facile one-pot hydrothermal method. Systematic analyses were performed to investigate the morphological-, structural- and optical-properties of the as-synthesized α-Fe 2 O 3 nanocubes. Continuous formation and hourly monitoring towards proper arrangement of single crystal α-Fe 2 O 3 nanocubes was observed throughout the hydrothermal heating process of 180 °C from 4 h to 12 h. The probable growth mechanism on the formation of cubic nanostructures is also proposed. Electron micrographs show the cubic α-Fe 2 O 3 synthesized at the most optimum 8 h hydrothermal heating duration are indeed produced in high-yield with a well-defined cubical shape. The typical rhombohedral structure of cubic α-Fe 2 O 3 was evident from the XRD pattern. The SAED pattern indicates that the α-Fe 2 O 3 nanocubes are single-crystalline in nature, with lattice-fringes and a d -spacing value of 3.6 Å. The optical characterization reveals that α-Fe 2 O 3 nanocubes show strong visible-light absorption with a band gap energy of ∼2.1 eV while the photoluminescence emission spectra depicts a mono-peak centered at ∼590 nm. Both the SAED pattern and UV-vis spectra show a strong correlation with the standard α-Fe 2 O 3 . The as-synthesized α-Fe 2 O 3 single crystal is of high quality that potentially could be used as a visible-light active nanomaterial in renewable energy device applications. Time-dependent morphological evolution analysis shows high quality crystalline α-Fe 2 O 3 nanocubes can be precisely tuned and synthesized by a facile, green, yet straightforward strategy via a hydrothermal method.