Synthesis of Mesoporous Single Crystal Co(OH)₂ Nanoplate and Its Topotactic Conversion to Dual-Pore Mesoporous Single Crystal Co₃O₄

A new class of mesoporous single crystalline (MSC) material, Co(OH)2 nanoplates, is synthesized by a soft template method, and it is topotactically converted to dual-pore MSC Co3O4. Most mesoporous materials derived from the soft template method are reported to be amorphous or polycrystallined; however, in our synthesis, Co(OH)2 seeds grow to form single crystals, with amphiphilic block copolymer F127 colloids as the pore producer. The single-crystalline nature of material can be kept during the conversion from Co(OH)2 to Co3O4, and special dual-pore MSC Co3O4 nanoplates can be obtained. As the anode of lithium-ion batteries, such dual-pore MSC Co3O4 nanoplates possess exceedingly high capacity as well as long cyclic performance (730 mAh g(-1) at 1 A g(-1) after the 350th cycle). The superior performance is because of the unique hierarchical mesoporous structure, which could significantly improve Li(+) diffusion kinetics, and the exposed highly active (111) crystal planes are in favor of the conversion reaction in the charge/discharge cycles.