Environmentally Benign Synthesis and Color Tuning of Strontium–Tantalum Perovskite Oxynitride and Its Solid Solutions

A facile method was successfully developed to prepare strontium-tantalum perovskite oxynitride, SrTaO2N, and its solid solutions. Urea employed as a nitriding agent eliminate the use of toxic NH3 gas. In addition, utilization sol-gel-derived Ta2O5 gel Ta precursor allowed for completion nitridation within shorter period at lower calcination temperature compared with conventional ammonolysis process. Optimization reaction conditions, such urea content, production solutions SrTaO2N Sr1.4Ta0.6O2.9. The products exhibited optical absorption chromatic colors because narrower band gaps oxynitrides those oxides. O/N ratios were easily adjusted by varying amount in mixture precursors. As result, ranged from yellow brown. process this study are interesting environmentally benign alternatives inorganic pigments.