Room Temperature Chemiresistive Sensing of Sulfur Mustard Simulant by 2D Conjugated MOF Surface Modification

Sulfur mustard (HD) is a powerful vesicant that inflicts fatal damage to humans. However, limited by the temperature-induced detection mechanism, chemiresistive gas sensing of HD or its simulants with high sensitivity and superior selectivity at room temperature remains a huge challenge. Herein, we propose a surface modification strategy for orthorhombic WO3·H2O using the epitaxial growth of a 2D conjugated MOF (2D c-MOF) based on the hard–soft acid–base theory. The interfacial electron delocalization from WO3·H2O to a 2D c-MOF strengthens the coordination interaction between tungsten (W) and sulfur (S) at room temperature, thus boosting the overall electron delocalization from the mustard gas simulant (2-CEES) to the sensing materials. As a result, the fabricated devices realize room temperature detection of 2-CEES with an impressive detection limit (100 ppb), excellent anti-interference ability, fast response, and good stability. Strategies modifying metal oxide surfaces with 2D c-MOFs provide new ideas for improving room temperature sensing performance.