Facile Synthesis and Optimization of High-Performance H₂S Gas Sensors Based on Pt-Co₃O₄@ZnO Nanofibers With Dual-MOF Structure

Metal-organic framework (MOF) materials are recognized as outstanding templates for preparing porous metal oxides used as gas-sensitive materials. Here, a facile synthesis strategy is proposed to prepare Pt-Co<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub>O<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub>@ZnO hollow porous nanofibers with MOF-on-MOF structure and noble metal for gas-sensing applications. Sensors fabricated with this unique nanomaterial show fast response, low detection limit (LOD), high selectivity, and good stability to H<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub>S gas. Notably, the gas response of the sensor with Pt-Co<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub>O<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub>/ZnO nanofibers is three times that for the sensor with Co<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub>O<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub>/ZnO, and the optimal operating temperature is reduced by <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$125~^{\circ }$ </tex-math></inline-formula>C. Furthermore, the gas-sensing mechanism is proposed in detail, and theoretical calculations based on the first principles further reveal the performance enhancement of Pt-Co<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub>O<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">4</sub>/ZnO nanofibers to H<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub>S. This study offers a strategy for fabricating noble metal-dropping dual MOFs-based nanofibers with abundant pores and high surface area for high-performance gas-sensing applications.