Alpha-MnO₂ nanorods are prepared by chemical method.

Difference in surface defect density is achieved.

Characterized using XRD, Rietveld, XPS, EDS, HR-TEM, BET, UV–vis absorption spectroscopy and PL spectroscopy.

Explains the bandstructure modification due to Jahn–Teller distortions using crystal field theory.

Modification in the intensity of optical emissions related to defect levels validates the concept of surface defect induced tuning of optical properties.