In Situ Single-phase\nFormation of LaCl(CN<sub>2</sub>) Mixed-Anion Compound Via Controlled\nPyrolysis of La<sup>3+</sup> Modified Melamine Precursor

Nitride (N<sup>3–</sup>) or cyanamide (CN<sub>2</sub><sup>2–</sup>) based mixed-anion compounds stand as\nattractive\nmaterials due to their unique properties derived from the binary or\nmultiple anions, although their synthesis remains challenging in incorporating\nthe N<sup>3–</sup> or CN<sub>2</sub><sup>2–</sup> anions\nsafely. This work highlights the first demonstration of in situ single\nphase formation of a LaCl(CN<sub>2</sub>) mixed-anion compound from\na stable single source precursor, melamine modified with LaCl<sub>3</sub> preparable under aqueous conditions. The in situ formation\nof LaCl(CN<sub>2</sub>) involves the chemical modification of melamine\nwith LaCl<sub>3</sub> to form a complex. Upon heating of the precursor\nunder N<sub>2</sub> flowing, this complex generates cyanamide species\naround 400 °C, which react with LaCl<sub>3</sub> and nonsublimated\nmelamine to afford a binary LaCl(CN<sub>2</sub>)/g-C<sub>3</sub>N<sub>4</sub> composite. Further pyrolysis at 800 °C decomposes the\ng-C<sub>3</sub>N<sub>4</sub> counterpart, resulting in the LaCl(CN<sub>2</sub>) single-phase formation. The electronic properties of the\nprecursor-derived single phase LaCl(CN<sub>2</sub>) were studied by\nthe density functional theory calculation and UV–vis spectroscopy\ncombined with X-ray photoelectron spectroscopy analyses and characterized\nby measuring 4.7, 1.8, and −2.9 eV for the band gap energy,\nthe valence band maximum, and the conduction band minimum relative\nto Fermi energy, respectively. This study paves the way for exploring\nvarious cyanamide-based mixed anion compounds, advancing their potential\napplications in various fields.