The　present　work　reports　the　preparation　of　porous　δ-Bi2O3　nanospheres　via　a　solvothermal　treatment　of　Bi(NO3)3·5H2O　in　the　mixed　solvent　of　ethanol　and　glycerol.　The　glycerol　is　found　to　play　a　vital　role　in　the　formation　of　δ-Bi2O3　nanospheres　not　only　the　particle　shapes　and　sizes,　but　also　the　porous　structures.　The　δ-Bi2O3　nanospheres　are　converted　into　semi-metallic　rhombohedral　bismuth　inheriting　the　morphological　properties　in　the　presence　of　NaBH4.　Furthermore,　the　reduction　reaction　of　nitrobenzenes　into　anilines　can　be　highly　achieved　over　the　in-situ　formed　bismuth　porous　nanospheres.　This　work　may　provide　a　new　method　for　the　preparation　of　porous　bismuth　and　bismuth　oxides,　and　open　the　way　to　a　range　of　important　application　of　bismuth　compounds.　©　2015　Elsevier　Ltd.