Single crystalline cubic sesquioxide bixbyite α-Mn2O3 nanorods have been synthesized successfully by a simple, low cost, environmental benign hydrothermal route. As synthesized γ-MnOOH were calcined at 600 °C to obtain α-Mn2O3 nanorods, which were further subjected to various characterizations. The alpha manganese sesquioxide cubic bixbyite-type oxide formation was confirmed by the XRD studies. The surface morphology and elemental analysis were explored by SEM with EDX studies, respectively. High-resolution transmission electron microscopy HRTEM and SAED showed that the α-Mn2O3 nanorods were single crystalline and were grown along the C-axis of the crystal plane. The UV-visible spectrum indicated that the absorption was prominent in the ultraviolet region. In addition, PL spectrum result of α-Mn2O3 nanorods recommended possible photocatalytic applications. The photocatalyst ensures a new platform for the decolorization of dye molecules of the harmful cationic dyes like methylene blue and rhodamine B. Possible growth mechanism and photocatalytic dye degradation mechanism were proposed for synthesized α-Mn2O3 nanorods. © 2020 The Author(s). Published by IOP Publishing Ltd.