F- dopants blocking hydroxyl interference: A facile solution for realizing humidity-resistive, selectivity adjustable, highly sensitive In2O3-based gas sensors

• Novel In 2 O 3-x F x sensing matrix was constructed for humidity-resistive detections. • M AC advances selectivity-tunable, highly sensitive, humidity-resistive sensors. • In-situ XPS results confirm hydroxylation inhibition behavior of F - dopants . • DFT calculations explore selectivity conversion and interaction mechanism of MOS . • In-situ DRIFTS explores reaction paths and humidity-resistive sensing mechanisms. Water poisoning is regarded as long-term challenges for metal oxide semiconductor gas sensors (MOS), which leads to severe signal drifts and overall sensing performance inhibitions. To tackle this issue, we propose a novel In 2 O 3 -based sensing platform that incorporates humidity-blocking sites using F - ions for realizing highly humidity-resistive gas-sensing detections. This strategy offers a feasible and reliable means to inhibit humidity interference without compromising intrinsic capabilities of the sensor. Additionally, the robustness and adaptability of the anti-humidity effect of F - have been validated through the implementation of functional Ni atomic cluster decorations, allowing for humidity-resistive, sensitivity-enhanced, and tunable selectivity in gaseous marker monitoring. Supported by DFT calculations and spectroscopy analyses, we demonstrate that the enhanced moisture tolerance provided by F - arises from its high electronegativity, which inhibits chemisorbed oxygen reactivity with adsorbed water molecules and prevents hydroxyl radical formations under extreme humidity conditions. These advancements establish a universal solution for designing humidity tolerant gas sensors, paving the way for the development of accurate and robust sensing arrays capable of multiple analyte recognitions in variable moisture environments.