Synthesis of ordered mesoporous transition metal dichalcogenides by direct organic-inorganic co-assembly

Endowing transition metal dichalcogenides (TMDs) with mesoporous structure can greatly enhance their porosity, accessible specific surface area, and exposed active sites, leading to better performances in applications based on interfacial reactions. Current methods including hard-template (nanocasting) method or thermal-assisted conversion (TAC) still suffer from drawbacks such as cumbersome and environmentally unfriendly process, humidity sensitivity, or ill-defined mesostructures. Herein, the study reports a facile synthesis of ordered mesoporous TMDs/carbon composites by direct organic-inorganic co-assembly in dual solvent (DMF/H${}_2$O). The amphiphilic block copolymer polyethylene oxide-b-polystyrene (PEO-b-PS) is used as the organic template, and (NH${}_4$)${}_2$MoS${}_4$ or (NH${}_4$)${}_2$ WS${}_4$ as the inorganic precursor. After solvent evaporation-induced aggregation assembly and thermal treatments, it results in highly ordered mesoporous MoS${}_2$, WS${}_2$, and MoS${}_2$/WS${}_2$ with highly crystalline framework, high specific surface area (44-91 m${}^2$ g${}^{-1}$) and large pore sizes (15-21 nm). Semiconductor gas sensors based on mesoporous TMDs exhibit extraordinary sensing performances toward NO${}_2$ at room temperature, including high sensitivity and ultrahigh selectivity, benefiting from its abundant adsorption sites for gas molecules, fast diffusion rate in well-connected mesopores, and rich edge active sites. This work paves a facile way to develop novel ordered mesoporous TMDs-based semiconductor materials for various applications. (© 2024 Wiley‐VCH GmbH)