In recent times, air pollution’s threat to humanity highlights the urgent need for advanced sensors to monitor harmful gases, essential for industrial regulation, gas leak detection, and air quality surveillance. Two-dimensional transition metal dichalcogenides (TMDCs) has garnered noteworthy attention as potential materials for gas sensing. This paper investigates the synthesis and characterization of a heterostructure composed of molybdenum diselenide with tungsten diselenide (MoSe2-WSe2) nanomaterials using a liquid phase exfoliation technique and it’s H2 sensing performance. The material characterisations confirmed the successful exfoliation into a hexagonal sheet-like, nanocrystalline MoSe2-WSe2 nanostructure. The study further assessed the sensor’s response to H2 gas, for concentrations of 5–25 ppm at room temperature, comparing the performance of MoSe2-WSe2 sensor with a pristine WSe2 sensor. The MoSe2-WSe2 sensor outperformed the pristine WSe2 sensor with a response of 59.57%, rapid response times and recovery times (16 s and 30 s respectively), low detection limit of 5.55 ppm, good repeatability, and high durability (30 days). Additionally, the impact of humidity was evaluated at 25 ppm H2 (at relative-humidity from 40% to 90%). The hydrophobic nature of MoSe2-WSe2 (CA = 141.4°) aligns with the first principle studies, showing almost no change in bandgap when exposed to humidity. These findings emphasize the potential of MoSe2-WSe2 heterostructure sensors for detecting H2 in humid conditions, filling a gap in research and advancing gas sensing technology for environmental safety.
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