Transformation of K2Sb8Q13 and KSb5Q8 Bulk Crystals to Sb2Q3 (Q = S, Se) Nanofibers by Acid–Base Solution Chemistry

The ability to manipulate crystal structures using kinetic control is of broad interest because it enables the design of materials with structures, compositions, and morphologies that may otherwise be unattainable. Herein, we report the low-temperature structural transformation of bulk inorganic crystals driven by hard–soft acid–base (HSAB) chemistry. We show that the three-dimensional framework K 2 Sb 8 Q 13 and layered KSb 5 Q 8 (Q = S, Se, and Se/S solid solutions) compounds transform to one-dimensional Sb 2 Q 3 nano/microfibers in N 2 H 4 ·H 2 O solution by releasing Q 2– and K + ions. At 100 °C and ambient pressure, a transformation process takes place that leads to significant structural changes in the materials, including the formation and breakage of covalent bonds between Sb and Q. Despite the insolubility of the starting crystals in N 2 H 4 ·H 2 O under the given conditions, th…