ZnSnO2N

ZnSnO2N is a ternary oxynitride compound composed of zinc, tin, oxygen, and nitrogen in the ratio ZnSnO2N. The structure is a layered perovskite-like lattice in which Sn4+ ions occupy octahedral sites surrounded by both O2− and N3− anions. The insertion of nitrogen into the otherwise oxysulfide framework results in a substantial band gap reduction compared to binary ZnSnO3, enabling visible‑light absorption and potential use in photocatalysis.

The compound is typically synthesized through high‑temperature solid‑state reactions or solvothermal routes. In a common solid‑state synthesis, stoichiometric amounts of ZnO, SnO2, and a nitrogen‑source such as urea or hydrazine are mixed, pressed into pellets, and heated at 700–900 °C under flowing nitrogen. The resulting product is polycrystalline and exhibits a rhombohedral or hexagonal symmetry depending on the synthesis conditions. Phase purity can be confirmed by X‑ray diffraction, while electron microscopy shows layered morphology with interlayer spacings consistent with the nitridation.

Optical characterization reveals an absorption edge around 3.0–3.4 eV, significantly lower than that of ZnSnO3 (≈3.8 eV). Photoluminescence spectra show emission peaks corresponding to defect states, which are often exploited for visible‑light driven catalysis. Electrochemical studies indicate respectable charge‑carrier lifetimes and a photocurrent response under blue light illumination, making ZnSnO2N a candidate material for solar‑water splitting and CO2 reduction. The presence of tin introduces additional conduction band states, facilitating electron transport, while zinc provides structural stability.

Recent literature reports the use of ZnSnO2N in composite films with graphene oxide to enhance photocatalytic degradation of organic dyes. Other studies explore doping with transition metals to further tailor band positions. While still in the research phase, ZnSnO2N demonstrates the promise of oxynitride materials as low‑cost, earth‑abundant photocatalysts for renewable energy applications.