Synthesis of MoO3/reduced graphene oxide hybrids and mechanism of enhancing H2S sensing performances

• MoO3/rGO hybrids were synthesized by an in-situ one-step microwave hydrothermal method.
• MoO3/rGO hybrids exhibit high sensitivity and selectivity to 40 ppm of H2S at 110 °C.
• MoO3/rGO hybrids show excellent stability and reproducibility at operating temperature of 110 °C.
• Sensing mechanism of MoO3/rGO to H2S was discussed from heterojunction concept.

The hetero-junction hybrids of 1-D molybdenum trioxide nanorods/reduced graphene oxide (MoO3/rGO) with different contents of rGO have been successfully synthesized by in-situ one-step microwave hydrothermal method. The morphology, structure and composition of the hybrids were characterized by FESEM, TEM, XRD, FT-IR, XPS, Raman and TG analysis, respectively. The sensing test results show that the novel hybrids not only exhibit enhanced sensitivity, good selectivity, fast response and recovery compared to that of pure MoO3 but also exhibit stability and reproducibility to ppm-level H2S at operating temperature of 110 °C. The sensing mechanism of hybrid to H2S is also discussed in detail. The improvement of sensing performance can be attributed to the formation of hetero-junction at the interface in hybrid, which renders the surface of the MoO3 nanorods more n-type, meantime facilitates the migration of electrons due to the incorporating of rGO. The study will offer wide application in efficient gas sensors.

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