Transformation of ZnO Nanobelts into Single-Crystalline Mn3O4 Nanowires

Single-crystalline Mn3O4 nanowires were prepared using the vapor-phase transformation of ZnO nanobelts. Mn3O4-decorated ZnO nanobelts and ZnO–ZnMn2O4 core–shell nanocables (NCs) were also obtained as reaction intermediates. Heteroepitaxial growth of tetragonal spinel Mn3O4 (or ZnMn2O4) on wurtzite ZnO is a possible reason for the growth of single-crystalline Mn3O4 nanowires. Growth interfaces are possibly formed between the wurtzite (101̅0)/(21̅1̅0) and spinel (1̅01)/(4̅11) planes. Various one-dimensional homonanostructures and heteronanostructures consisting of n-ZnO, p-Mn3O4, and p-ZnMn2O4 can be used to design high-performance gas sensors.