HHTP surface-functionalized copper sulfide hollow nanocubes with sensitivity-boosted and high-concentration ammonia sensing

Ammonia (NH3) sensing is simultaneously required with high selectivity, stability, low detection limit and wide concentration range detection for monitoring NH3 leakage, however, remains challenging. Here, Copper sulfide (CuxS) hollow nanocubes functionalized with 2,3,6,7,10,11-hexahydroxytriphenylene molecules (HHTP@CuxS NCBs) have been developed for improving NH3 sensing performance at room temperature via using Cu2O NCBs as precursor and template, followed by partial sulphidizing, core etching and HHTP-functionalized processing. Typically, HHTP molecules are characterized in-situ grown on CuxS surface, and abundant floccules are observed after functionalization. Beneficially, HHTP@CuxS NCBs show 126-fold improvements in sensing response to 1000 ppm NH3, compared to those of the CuxS NCBs. Further, the sensor prototype shows a 0.3–10000 ppm detection range, 0.3 ppm detection limit, excellent repeatability and 33 days-long stability at room temperature. Theoretically, such outstanding NH3 sensing performance might be attributed to the abundant sites of π-conjugated HHTP molecules and the hollow NCBs' structure. Practically, a HHTP@CuxS NCBs sensor prototype has been simulated to detect NH3 with a reliable response.