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Graphical abstract Highlights • NiO, a new cataluminescence sensing material, was synthesized by a simple template-free hydrothermal method. • Camellia-like NiO with high specific surface area showed excellent sensing performance towards H 2 S. • The sensing mechanism was studied which proved the main emission peak is from SO 2 *. Abstract In this work, three different microstructures of NiO nanomaterials including tremella, camellia and hexagonal nanosheets were successfully synthesized by a simple template-free hydrothermal method. Among them, camellia-like NiO was reported and applied to cataluminescence (CTL) for the first time. SEM, TEM, XRD, XPS, BET and BJH were employed to characterize the as-prepared samples. As sensing materials, these NiO with various morphologies showed different CTL capabilities to detect H 2 S, and the camellia-like NiO exhibited the best catalytic performance with high sensitivity and selectivity, which may be attributed to the synergistic effect of its high specific surface area, porous nanostructure, as well as the surface adsorption oxygen. After optimization, a good linear relationship was obtained in the range of 0.8–30.8 ppm and the detection limit (S/N = 3, LOD) was 0.3 ppm. Sixteen common volatile organic compounds (VOCs), such as carbon disulfide, ethyl mercaptan and formaldehyde, were discussed as possible interferent components, and the sensing mechanism of the CTL sensing towards H 2 S was discussed in detail. Camellia-like NiO could be used as a new sensing material for H 2 S monitoring. [ABSTRACT FROM AUTHOR]

• A novel methodology for rapidly detecting and identifying BTEX based on energy transfer ratiometric cataluminescence. • BTEX exhibit different energy transfer processes to Eu3+ and Tb3+ on the surface of Eu,Tb-MgO nanomaterial. • The synergistic effect of ozone induction and high active sensing material enhanced sensitivity of BTEX. The detection and discrimination of benzene, toluene, ethylbenzene and xylene (BTEX) are tricky and challenging issues no matter in environmental monitoring or process controlling in industrial fields. Herein, an ozone-inducted ratiometric cataluminescence strategy for fast quantifying and recognizing BTEX was developed. With ozone as oxidant and rare earth ions Eu3+, Tb3+ co-doped MgO nanocatalyst as sensing material, BTEX were found to produce strong cataluminescence (CTL) emission. And each analyte has unique ratio of the intensities under the characterization wavelength of Eu3+ and Tb3+ in a wide range of concentrations, which can be assumed as the qualitative parameter for BTEX recognition. On that basis, BTEX were supposed to be identified successfully with discrepant ratios for I Eu /I Tb of 0.73 ± 0.03, 1.34 ± 0.03, 4.47 ± 0.18, 2.39 ± 0.11, and measured simultaneously with detection limit of 0.13, 0.21, 0.092, 0.053 μg ml−1, respectively. Besides, the prepared catalysts were characterized and the possible CTL sensing recognition mechanism for BTEX were discussed in detail. The proposed methodology provides a new insight for monitoring and identifying low active compounds. [ABSTRACT FROM AUTHOR]

Vacancy regulation is considered to be an effective means to improve the properties of materials, which has been applied in the fields of catalysis, electricity and optics. Herein, different contents of nitrogen vacancy in graphitic carbon nitride (g-C 3 N 4) could be modulated via changing temperature of secondary calcination. Results showed the introduction of nitrogen vacancy significantly promoted the cataluminescence (CTL) intensity towards ammonium sulfide ((NH 4) 2 S) and the CTL performance increased regularly with the increaseing vacancy content. The positive effect of nitrogen vacancy on CTL intensity of (NH 4) 2 S was unveiled in-depth by the experiment and density functional theory (DFT). Moreover, a cutting-edge CN-600-based sensor was established for the highly sensitive detection of (NH 4) 2 S. The sensor possessed excellent selectivity and stability, and a low detection limit (0.16 μg mL−1). Noteworthily, this study presents novel mentality for designing materials with improved catalytic activity. [Display omitted] • The nitrogen vacancy content in g-C 3 N 4 was successfully modulated by adjusting temperature of secondary calcination. • The mechanism of enhanced CTL performance of (NH 4) 2 S on g-C 3 N 4 surface modulated by nitrogen vacancy was revealed. • The constructed CN-600-based sensor exhibited excellent selectivity and stability for (NH 4) 2 S sensing. [ABSTRACT FROM AUTHOR]