CuO-Modified FePS3 Monolayer: A Two-Dimensional Sensing Material for Room Temperature Capture and Efficient Detection of VOCs.

Although the development of gas sensing materials for room temperature operation is of great importance for environmental management, computational studies usually overlook the effectiveness of the adsorbent under realistic conditions. The FePS3 monolayer has recently been synthesized and recognized as a novel two-dimensional (2D) material with favorable electrical properties, but its potential for gas-sensing applications remains unexplored. In this study, first-principles calculations are employed to systematically investigate the feasibility of pristine and CuO-modified FePS3 monolayers for the detection of volatile organic compounds (VOCs). Relative energy is employed to evaluate the adsorption effectiveness of VOCs at different temperatures. The results demonstrate that VOCs are weakly physisorbed on the pristine FePS3 monolayer, resulting in poor adsorption stability. The introduction of CuO strengthens the adsorbate-substrate interactions by enhancing orbital hybridization and charge transfer between VOCs and the FePS3 monolayer. At room temperature, the CuO-modified FePS3 monolayer can stably capture VOCs and achieve repeated detection of CHCl3, CH3Cl, and CH2O with short recovery times. Moreover, the CuO-modified FePS3 monolayer exhibits high sensitivity and excellent selectivity toward VOCs, enabling its use as a high-performance resistance-type gas sensor. Our work reveals the potential of the FePS3 monolayer for gas sensing applications and promotes the design of gas sensors based on 2D metal phosphorus chalcogenides.