An ultra-sensitive NH3 gas sensor enabled by an ion-in-conjugated polycroconaine/Ti3C2Tx core-shell composite

Jin Zhou, Seyed Hossein Hosseini Shokouh, Linfan Cui, Topias Järvinen, Olli Pitkänen, Zhong-Peng Lv*, Krisztian Kordas*

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

1 Citation (Scopus)
6 Downloads (Pure)


MXenes are emerging sensing materials due to their metallic conductivity and rich surface chemistry for analytes; they, however, suffer from poor stability. Incorporation with functional polymers can largely prevent the performance decay and enhance the sensing performance. Herein, we demonstrate a core-shell composite, Ti3C2Tx@croconaine (poly(1,5-diaminonaphthalene-croconaine), PDAC) prepared by a facile in situ polymerization reaction, suitable for NH3 detection. Compared to pristine Ti3C2Tx, the sensor made of a Ti3C2Tx-polycroconaine composite exhibits a significantly enhanced sensitivity of 2.8% ppm−1 and an estimated achievable limit of detection of 50 ppb. The improved sensing performance could be attributed to the presence of PDAC facilitating the adsorption of NH3 and changing the tunneling conductivity between Ti3C2Tx domains. Density functional theory (DFT) calculations reveal that the adsorption energy of NH3 on PDAC is the highest among the tested gases, which supports the selectivity of the sensor to this analyte. Benefiting from the protection conferred by the PDAC shell, the composite has a reliable operation period of at least 40 days. In addition, we demonstrated a flexible paper-based sensor of the Ti3C2Tx@PDAC composite, without attenuated performance upon mechanical deformation. This work proposed a novel mechanism and a feasible methodology to synthesize MXene-polymer composites with improved sensitivity and stability for chemical sensing.

Original languageEnglish
Pages (from-to)794-802
Number of pages9
JournalNanoscale Horizons
Issue number6
Early online date14 Mar 2023
Publication statusPublished - 1 Jun 2023
MoE publication typeA1 Journal article-refereed


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