Flame Aerosol Synthesis of Metal Sulfides at High Temperature in Oxygen‐Lean Atmosphere

The development of a novel reactive spray technology based on the well‐known gas‐phase metal oxide synthesis route provides innumerable opportunities for the production of non‐oxide nanoparticles. Among these materials, metal sulfides are expected to have a high impact, especially in the development of electrochemical and photochemical high‐surface‐area materials. As a proof‐of‐principle, MnS, CoS, Cu2S, ZnS, Ag2S, In2S3, SnS, and Bi2S3 are synthesized in an O2‐lean and sulfur‐rich environment. In addition, the formation of Cu2S in a single‐droplet combustion experiment is reported. The multiscale approach combining flame sprays with single‐droplet combustion is expected to pave the way toward a fundamental understanding of the gas‐phase formation of metal sulfides in the future. The knowledge acquired can open the possibility for the development of a next‐generation gas‐phase technology facilitating the scalable synthesis of functional binary/ternary metal sulfides. As proof‐of‐principle, the preparation of various metal sulfides in a flame process using single‐droplet combustion and enclosed flame spray pyrolysis in O2‐lean condition is demonstrated. Using a large‐tube reactor MnS, CoS, Cu2S, ZnS, Ag2S, In2S3, SnS, and Bi2S3 are formed at a rate of 5 g h−1. The flame aerosol process is a key toward scalable synthesis of binary/ternary metal sulfides for next‐generation functional materials.