LiNH-Based Nitridation Synthesis and Structure Analysis of GaN:ZnO Solid Solutions.

The GaN:ZnO solid solution is a visible-light-absorbing material widely developed for photocatalytic applications. For the first time, we demonstrate that a molecular source of LiNH significantly enhances the synthesis of GaN:ZnO solid solutions by leveraging its high reactivity in molten lithium chloride. Most notably, LiNH dramatically accelerates the nitridation reaction of gallium chloride (GaCl) and zinc chloride (ZnCl) or zinc oxide (ZnO), enabling the rapid formation of GaN:ZnO within just 2 h at a relatively low temperature of 650 °C. This marks a significant improvement over conventional ammonia gas synthesis methods, which typically require more than 10 hours. Furthermore, this approach eliminates the need for toxic ammonia gas and metal nitrate oxidizers, providing a safer and more environmentally sustainable pathway for material synthesis. Comprehensive structural and elemental analyses, including XRD, TEM, and XRF, confirmed the formation of highly crystalline GaN:ZnO solid solutions, revealing varying levels of reaction uniformity at the atomic scale under different zinc sources and Zn/Ga ratio conditions. The light absorption edges of the materials ranged from 500 nm to 650 nm, depending on the zinc content and source. These findings establish a novel and efficient synthesis strategy for GaN:ZnO solid solutions, paving the way for their development in visible-light-driven applications.