Synthesis and characterizations of 3D Co3O4 hierarchical microcrystals

•α-Co(OH)2 flower-like structures were prepared by surfactant-assisted chemical route.•Co3O4 flower-like structures were achieved by annealing α-Co(OH)2 structures.•Co3O4 flower-like structures exhibit a broad emission feature in the visible range.•PL emission likely originates from the indirect optical band gap emission.•Co3O4 flower-like structures may be used as new visible light emitting materials.

AbstactThree-dimensional (3D) Co3O4 hierarchical microcrystals assembled by two-dimensional (2D) plate-like nanocrystals have been successfully prepared via annealing 3D α-Co(OH)2 hierarchical microcrystals. XRD results demonstrated that the pure phase α-Co(OH)2 hierarchical microcrystals were converted into pure cubic phase Co3O4 hierarchical microcrystals after annealing at 400 °C for 2 h. SEM observations show that the as-achieved 3D Co3O4 hierarchical microcrystals are built by 2D plate-like nanocrystals. Room temperature photoluminescence shows that the as-obtained 3D Co3O4 hierarchical microcrystals exhibit a broadened visible emission in the range of 650–760 nm with a center peak at around 745 nm (1.67 eV), which may lead these 3D Co3O4 hierarchical microcrystals to potential applications in visible light emitting materials and nanodevices.

Graphical abstract3D Co3O4 flower-like hierarchical microcrystals with unique visible light photoluminescence have been prepared by annealing 3D α-Co(OH)2 flower-like hierarchical microcrystals.Figure optionsDownload full-size imageDownload as PowerPoint slide