Exploring monolayer Ta4C3Tx MXene for quick ammonia detection at room temperature

Two-dimensional (2D) MXenes have emerged as promising gas sensor materials due to their abundant surface functional groups, excellent conductivity, and large surface area. In this work, we synthesized 2D Ta 4 C 3 T x nanosheets via hydrofluoric acid (HF) etching followed by a tetramethylammonium hydroxide (TMAOH) intercalation treatment. Systematical characterization reveals the as-prepared 2D Ta 4 C 3 T x exhibits promising monolayer morphology with abundant oxygen containing functional groups. The sensor device based on monolayer Ta 4 C 3 T x presents a brilliant response to ammonia gas at room temperature, well surpassing those based on other previously reported MXenes. The high selectivity of Ta 4 C 3 T x for ammonia gas was explored through first-principle calculations. This study highlights the significant potential of monolayer Ta 4 C 3 T x for developing high-performance room-temperature ammonia gas sensors.