MXene-Based Room-Temperature NO₂ Gas Sensors: A Meta-Analysis

The rapidly developing field of MXene-based room-temperature NO₂ gas sensors is characterized by significant heterogeneity in material synthesis, treatment methods, and sensor design. This variation complicates the identification of best technological practices and hinders direct comparison of reported performance metrics. This study addresses this challenge by performing the first comprehensive meta-analysis of 1243 individual sensor measurements from 61 published, peer-reviewed papers. The analysis establishes comparable key performance metrics for quantitative synthesis, including normalized sensing response, breakpoint, and sensitivity, and identifies a wide range of explanatory variables, with modifier type, intercalation, synthesis approach, surface state, and post-synthesis treatment being the most influential factors, and a smaller contribution from morphology, while device-level parameters such as electrode material are secondary. The resulting multidimensional analysis yields a quantitative assessment of structure-property-performance drivers and exposes systematic gaps in current sensor design. Beyond consolidating a fragmented literature, this work establishes a methodological blueprint for translating data heterogeneity into generalized design rules, accelerating the rational development of high-performance MXene-based chemical sensors.