Bio-Inspired Synthesis of Hematite Mesocrystals by Using Xonotlite Nanowires as Growth Modifiers and Their Improved Oxygen Evolution Activity

Bio-inspired synthesis of functional materials with highly ordered structure and tunable properties is of particular interest, but efficient approaches that allow the access of these materials are still limited. A method has been developed for the preparation of hematite particles by using xonotlite nanowires (XNWs) as growth modifiers. The concentration of the XNWs has a profound effect on the final morphology of the products, whereas the concentration of the iron(III) ions can control the size of the hematite particles. The underlying mechanism of the bio-inspired XNW-modified mineralization process has been proposed. The obtained hematite particles exhibit good catalytic performance in the oxygen evolution reaction (OER), affording a current density of 10 mA cm^-2 with an overpotential of 370 mV, a small Tafel slope of 65 mV dec^-1 , and good stability in alkaline electrolyte. This strategy for preparing functional materials by using nanowires as the growth modifiers has great potential for future application in the construction of various materials with hierarchical structures.