Hierarchical MoS2 Nanostructured Tubes on Biodegradable and Flexible Chitosan-Based Platform for Low-Temperature Hydrogen Detection

The importance of flexible gas sensors is increasingly recognized for their adaptability across various applications. However, the commonly used flexible substrates are synthetic and nonbiodegradable, contributing to environmental pollution. To mitigate this issue, there is a growing focus on developing low cost, environmentally friendly flexible substrates for electronic devices. In this study, we present an efficient approach aimed at fabricating a cost-effective flexible chitosan platform embedded with molybdenum disulfide (MoS2) nanostructured tubes synthesized via a hydrothermal method. This flexible platform, combined with MoS2, underwent meticulous morphological characterization and comprehensive evaluation for detecting hydrogen (H2) gas at $50~^{\circ }$ C. The device at $50~^{\circ }$ C exhibited a 300% higher response by proportion for 50-ppm H2 compared to those operating at room temperature (RT), demonstrating its enhanced performance at lower temperatures. Furthermore, the sensor also demonstrated excellent repeatability and bendability characteristics, along with a notable selectivity toward H2 over other gases, such as H2S, NH3, and NO2, achieving a low limit of detection (LOD) of ~28 ppb. In a nutshell, these findings emphasize sustainable and biodegradable sensors with good sensitivity, repeatability, and selectivity, for detecting H2, particularly at a lower temperature.