Self‐Hybrid Transition Metal Oxide Nanosheets Synthesized by a Facile Programmable and Scalable Carbonate‐Template Method

Abstract 2D transition metal oxides (TMO) nanosheets have attracted considerable attention in both fundamental research and practical applications. Herein, a convenient programmable and scalable carbonate crystals templating synthesis is developed to produce high‐quality self‐hybrid TMO nanosheets (Si‐WO_3−x, Ta_xO_y, Mn_xO_y) and their respective polymetallic oxide hybrid nanosheets with tunable composition, low‐cost and high‐yield. Taking tungsten oxide nanosheets as example, silicotungstic acid precursor is in situ converted into tungsten oxide nanosheets like scales on the surface of calcium carbonate crystals through the simple soaking‐drying‐calcination process, and after selectively dissolving calcium carbonate by etching, the dispersive tungsten oxide nanosheets with unique self‐hybrid Si‐doped h‐WO₃/ε‐WO₃/WO₂ compositions are obtained, which show excellent acetone gas‐sensing performances at low temperatures. This carbonate‐template method opens up the possibility to economically produce various functional TMO nanosheets with specific compositions for diverse applications.