Semiconductive (Cu–S)n Metal–Organic Frameworks Hybrid Polyaniline Nanocomposites as Hydrogen Sulfide Gas Sensor

A semiconductive (Cu–S)n metal–organic framework (MOF) incorporated polyaniline (PANI) nanocomposite was applied for hydrogen sulfide (H2S) gas sensing. The (Cu–S)n MOF nanosheets were successfully synthesized using a one-pot reflux method. First, fiber-like (Cu–S)n MOF/ PANI nanocomposites were prepared through an in situ oxidative polymerization. As evaluated by field-emission transmission electron microscopy (FE-TEM), the nanosized spherical (Cu–S)n MOF particles were well-distributed in the fiber matrix. Then, the nanocomposite was spin-coated onto an interdigitated electrode (IDE) for H2S gas sensing, displaying high sensitivity, selectivity, repeatability, and stability similar to pure PANI. As a result, 3wt% (Cu–S)n MOF/ PANI nanocomposite showed the best performance for H2S detection. The mechanism for improving H2S sensing performance might be attributed to the conductive composite networks' significantly enhanced conductivity and increased doping sites of the (Cu–S)n MOF. In addition, the energy band gaps of PANI-based nanocomposites were optimized by the incorporated (Cu–S)n MOF, indicating the successful hybridization of energy levels between inorganic MOF and organic PANI. This study first demonstrates semiconductive MOF-PANI-based nanocomposites for H2S gas sensing.