Enhanced sensitivity of zero-bias-operated MXene chemiresistive sensor via lignin hybridization

As global urbanization intensifies, there is an increasing need for highly sensitive and accurate environmental monitoring devices that can meet the demands of specific gas sensing applications with low power consumption. This study focuses on enhancing the sensitivity of MXene-based chemiresistive sensors for detecting CO_2(g) and NO_2(g) under zero-bias operation. This study shows that lignin hybridization effectively improves the sensitivity of a Ti₃C₂T_x MXene-based chemiresistive sensor; under zero-bias operation, lignin hybridization increases the sensitivity to 15 ppm NO_2(g) and CO_2(g) by 157.38% and 297.95%, respectively. When deposited on a flexible substrate, the MXene/lignin flexible sensor shows a similar response and sensitivity to 15 ppm NO_2(g) and CO_2(g) under 38° curvature compared to the planar sensor. Consequently, the MXene/lignin hybrid sensor is attractive for room temperature and zero-bias NO_2(g) and CO_2(g) detection. The MXene/lignin flexible sensor serves as a model system for advanced solid-state sensory platforms suitable for curved structures.