Hierarchical hollow MoS₂ microspheres as materials for conductometric NO₂ gas sensors

Surface structure control at the atomic scale is an efficient strategy for improving the performance of gas sensing. Herein, hierarchical hollow MoS₂ microspheres with enhanced performance for NO₂ gas sensing were synthesized via a facile hydrothermal method. The introduction of micro-nano hierarchical structure improved the exposure of active edge sites of MoS₂, and the efficiency of gas and carriers exchange and transportation during the reaction, which synthetically contribute the sensing performance enhancement. With additional optimization of reaction conditions, the hierarchical hollow MoS₂ microspheres show excellent sensing performance with 3.1 times enhancement compared with the contrast sample of smooth solid structure. The rapid and sensitive response, decreased working temperature, as well as the prominent selectivity, enable the material with attractive sensing performance for NO₂ detection. This study provides new opportunities on the surface morphology control at both the micro- and nanoscale for enhancing the sensing performance of MoS₂.