Single-crystalline　beta-MnO2　nanorods　were　successfully　synthesized　through　facile　reflux　treatment　of　KMnO4　and　MnSO4　in　HNO3　solution.　TEM　and　SEM　images　show　that　the　synthesized　beta-MnO2　nanorods　exhibited　diameters　of　20-50　nm,　and　lengths　that　ranged　from　approximately　0.5　to　2.0　mu　m　with　decreasing　HNO3　concentrations　from　0.8　to　0.1　mol/L　The　beta-MnO2　nanorods　underwent　three　primary　evolutionary　stages　over　time.　They　exhibited　excellent　catalytic　properties　for　the　degradation　of　methylene　blue　(MB)　by　a　Fenton-like　reaction.　(C)　2011　Elsevier　B.V.　All　rights　reserved.