NixCu3−x(HHTP)2 decorated poly-pyrrole porous nanocomposites for highly selective and stable hydrogen sulfide sensing at room temperature

Abstract

Hydrogen sulfide (H2S) sensing with high selectivity and stability is required for environmental monitoring at room temperature, however, needs further exploring. Here, NixCu3−x(HHTP)2 decorated over poly-pyrrole nanocomposites {NixCu3−x(HHTP)2/PPy NCPs, HHTP = 2,3,6,7,10,11-hexahydroxytriphenylene} have been developed for highly selective and stable H2S sensing at room temperature (∼ 25 ⁰C), which have been synthesized by firstly oxidating polymerizing poly-pyrrole nanoparticles and subsequently decorating with NixCu3−x(HHTP)2 metal-organic frameworks (MOFs) via a hydrothermal process. Typically, the NixCu3−x(HHTP)2/PPy NCPs are observed with spiny surface and are characterized with amorphous crystallization. Beneficially, the NixCu3−x(HHTP)2/PPy NCPs show excellent selectivity to H2S even in the presence of other interfering gases and display a 70 days-long stability that maintains 77.3% response at room temperature (∼ 25 ⁰C). Further, the sensor prototypes enable to detect H2S as low as 500 ppb and show stability against humidity, respectively. Theoretically, such excellent H2S sensing performance might be attributed to the charge transfer between H2S molecules and utilized copper, fast charge transports via forming bimetallic MOFs and the counteraction of PPy NPs to interfering gas. Practically, a H2S sensing device built with the NixCu3−x(HHTP)2/PPy prototype has been integrated to detect H2S with excellent sensing response.