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The emission of volatile sulfur compounds (VSCs) could cause environmental pollution, low-grade products and human health risks. Accordingly, it is of great significance to establish some sensitive and convenient analytical methods for their identification and determination. With the advantages of fast response, high sensitivity and simple instrument, chemiluminescence (CL) and cataluminescence (CTL) are promising for the detection of VSCs. So far, CL analysis of VSCs has been widely applied in various fields based on auxiliary CL methods and sulfur chemiluminescence detector (SCD), while CTL detection is prosperous in the construction of gas sensors, including the exploration of sensing materials and detection modes. Herein, this mini review briefly summarized the progresses, difficulties and future developments of CL analysis and CTL sensor in the detection of VSCs. [ABSTRACT FROM AUTHOR]

Ratiometric luminescent sensors have been of considerable interest to the chemo/biosensor with the ability of providing a precisely quantitative and qualitative analysis. The main strategies for generating dual emissions from single-fluorophore and double-fluorophore are summarized and categorized in detail. Typically, dual emission can be obtained either with fluorescence resonance energy transfer or intramolecular charge transfer. The discovery of aggregation induced emission offers new opportunities for ratiometric sensing. Ratiometric phosphorescence and chemiluminescence analysis are also promising for sensing. The recent progress for applications of ratiometric luminescent method is addressed and summarized here, which shows that ratiometric luminescent method can be used not only to selectively quantify one substance, but also to qualitatively recognize different substances. [ABSTRACT FROM AUTHOR]

Cataluminescence (CTL), a kind of chemiluminescence emitted at the gas–solid interface during catalytic oxidation reactions, has been developed for many decades as a novel and promising gas sensing technique. In this review, we introduce the origin, basic principles, and mechanisms of CTL sensing systems and summarize the recent advances in CTL sensing, focusing on methodologies and extended applications such as in gas selective monitoring, recognition of complex mixture, evaluation for catalytic property and use in high‐performance liquid chromatography, capillary electrophoresis and gas chromatography detectors. In addition, development prospects and some challenges facing CTL‐based sensing are also discussed. [ABSTRACT FROM AUTHOR]

Cataluminescence (CTL), one kind of the chemiluminescence, generates on the surface of solid catalyst during a heterogeneous catalytic oxidation reaction with the advantages of high sensitivity, fast response, simple instrument and longtime stability. This review provides the advances in CTL, mainly discussed the developments of sensing materials, detection technologies and application of CTL in recent 3 years. Also, we proposed various prospects and expectations of CTL-based sensor system at the end of this paper. [ABSTRACT FROM AUTHOR]

Material morphology-dependent cataluminescence (CTL) sensing characteristic and application are presented in this work. Hierarchical hollow microspheres CeO2 were synthesized via the hydrothermal reaction of glucose and N, N-dimethyl-formamide (Glu-DMF). SEM, XRD, TEM, HRTEM and BET were used to characterize the prepared CeO2 materials. Compared with CeO2 cubics (CeO2 Cubs), CeO2 hierarchical hollow microspheres (CeO2 HMs) show an enhanced CTL response to carbon disulfide. The response and recovery times of CeO2 HMs-based CTL sensor towards carbon disulfide are about 8 s and 20 s, respectively. CeO2 HMs exhibits a linear CTL response to carbon disulfide in the concentration range of 0.50~10 μg•mL-1 with an excellent sensitivity and selectivity. These results suggest that CeO2 HMs will be a highly promising CTL sensing material for the detection and monitoring carbon disulfide.CeO2 hierarchical hollow microspheres (CeO2 HMs) were synthesized via the hydrothermal reaction of glucose and N, N-dimethyl-formamide (Glu-DMF). Meanwhile, the prepared CeO2 HMs shows commendable CTL response towards carbon disulfide. Due to the excellent analytical performance of designed CeO2 HMs-based sensor for carbon disulfide, it has potential application value in various locations [ABSTRACT FROM AUTHOR]

Abstract: A novel and highly sensitive gas sensor for alcohols (methanol, ethanol, propanol, isopropanol, butanol, and isobutanol) was proposed based on cataluminescence (CTL) on the surface of nano-CdS. Using cetrimonium bromide (CTAB) as template, the nano-sized sensing material CdS was successfully obtained by a simple hydrothermal synthesis process. The luminescence characteristics and the experiment conditions were investigated in detail. Under the optimized conditions, little interference was observed while eleven foreign substances were passing through the sensor. It demonstrated that this gas sensor has high selectivity for alcohols. The calibration curve (y = kx + b) of the relative CTL intensity versus the concentration of methanol was made, with the linear range of 1.2–76.1μgmL−1 and the detection limit of 0.5μgmL−1 (S/N=3). The relative standard deviation (R.S.D.) (n =7) of relative cataluminescence intensity for 58.5μgmL−1 methanol was 4.3%. There was no significant change of the catalytic activity of the sensor for a week, with R.S.D. less than 5% by collecting the CTL intensity every hour. The method can be applied to detect alcohols in the air. The possible mechanism of CTL on the surface of nano-CdS was discussed preliminarily. [Copyright &y& Elsevier]

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]

In the present paper, we have successfully synthesized three new morphologies of enclosed hollow tubular, porous penoy-like and rose-like ZnO architectures via a facile hydrothermal route. The SEM, XRD, TEM, HRTEM and N 2 adsorption–desorption measurements were employed to characterize the as-synthesized ZnO materials. Results of HRTEM exhibited that the exposed crystal facet of enclosed hollow tubular was {10 1 ¯ 0}, while that of the penoy-like and rose-like were both {11 2 ¯ 0}. Moreover, a possible growth mechanism of enclosed hollow tubular ZnO was deduced by exploring the products gathered at different reaction stages and the effects of influencing parameters on cataluminescence (CTL) sensing were also researched. Experimental results indicated that the assorted morphological with different exposed crystal facets ZnO materials exhibited distinctly disparate CTL behavior to detect H 2 S gas and the enclosed hollow tubular ZnO showed the highest catalytic capability. In order to scrutinize the analytical characteristics of the CTL sensor based on enclosed hollow tubular ZnO towards H 2 S, further study was carried out under the optimal experimental conditions. What’s more, gas sensing tests revealed that the enclosed hollow tubular ZnO could have the potential applications as advanced gas sensing materials owning to its excellent gas sensing performances. [ABSTRACT FROM AUTHOR]

A novel and facile dielectric barrier discharge (DBD) plasma-based strategy for fast fabrication of g-C 3 N 4 -Mn 3 O 4 composite is developed. The obtained g-C 3 N 4 -Mn 3 O 4 can be used as a superior cataluminescence (CTL) catalyst for H 2 S gas sensing, with excellent selectivity, high sensitivity, rapid and stable response. Sub-ppm level H 2 S is able to be detected based on the proposed sensor, providing a splendid alternative for monitoring H 2 S in various fields. SEM, TEM, XPS, XRD, N 2 adsorption–desorption measurement were employed to characterize the as-synthesized sensing material. The composite possesses smaller particle size and enlarged specific surface area, which might be attributed to the oxidizing non-equilibrium plasma etching. Besides, using Mn 2+ -impregnated g-C 3 N 4 as the only precursor and air as working gas, this synthesis is free of solvent, extra oxidant/reductant or high temperature, offering advantages such as simplicity in construction, convenient operation and fast speed, and it could be easily implemented on a large scale and extended to manufacturing diverse metal oxide-modified composites for different purposes. [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]

A novel gas sensor toward ketones based on cataluminescence generated on the surface of nanosized NaYF 4 :Er was developed. The sensing materials NaYF 4 :Er was synthesized by a simple hydrothermal method and characterized by powder X-ray diffraction, scanning electron microscope and energy dispersive X-ray spectroscopy. The effect of Er 3+ doping concentration and crystallinity of NaYF 4 :Er on the CTL intensity were studied. When the Er 3+ doping concentration reaches 20%, the materials show excellent sensing characteristics for ketones. Under the optimal experimental conditions, as represented by the acetone and butanone, the gas sensor has fast responses (3 s) and relatively low work temperature (250 °C). The linear range of cataluminescence intensity versus concentration were 2.388–143.28 μg mL −1 for acetone and 2.45–49.0 μg mL −1 for butanone, with a detection limit (signal-to-noise ratio is 3) of 1.7 μg mL −1 and 0.7 μg mL −1 , respectively. Foreign 11 substances in common have little interference which indicates the high selectivity of the CTL sensor for ketones. [ABSTRACT FROM AUTHOR]

In the present work, a novel H 2 S cataluminescence (CTL) sensor based on metal-organic frameworks (MOFs) was established. Four MOFs, including MIL-100(Fe), MIL-101(Cr), Zn 3 (BTC) 2 ·12H 2 O and ZIF-8 were tested as CTL sensing materials. Among them, MIL-100(Fe) showed high CTL intensity for H 2 S, but it would be damaged after CTL experiment. MIL-101(Cr) showed just a low CTL signal and also destructed after contacting with H 2 S. Excitingly, Zn 3 (BTC) 2 ·12H 2 O and ZIF-8 displayed good sensitivity and stability for H 2 S. Then, the CTL characteristics and optimal parameters of these two MOFs were investigated in detail and the possible CTL mechanism was also discussed. Under the optimized conditions, the calibration curves of CTL intensity versus H 2 S concentration have linear regression coefficients ( R ) of >0.99 at low concentration, which renders MOFs interesting candidates for constructing H 2 S CTL sensor. [ABSTRACT FROM AUTHOR]

Cataluminescence (CTL) was regarded as a simple and efficient sensing method and had made great contributions in gas sensing. Herein, a novel CTL sensor based on Ce(IV)-MOF was designed for detection of H 2 S. The sensor shows outstanding selectivity, high sensitivity and excellent stability in CTL towards H 2 S due to the large surface area and excellent stability of Ce(IV)-MOF. A good linear curve (R2 =0.997) between CTL intensity and H 2 S in the range of 1.04–21.0 μg/mL was obtained with the detection limit of 0.035 μg/mL. Besides, the investigation of the CTL mechanism provides more theoretical support for catalytic reaction. This work broadened the application field of MOF and provided a new clue for the development of catalytic materials in CTL. • Cataluminescence gas sensor with outstanding selectivity, high sensitivity and excellent stability towards H 2 S. • The CTL sensor has excellent thermal stability, porous structure, large surface area and high catalytic activity. • The catalytic oxidization and luminescence mechanism of H 2 S on Ce(Ⅳ)-MOF was investigated in detail. [ABSTRACT FROM AUTHOR]

α-Fe 2 O 3 /g-C 3 N 4 composites catalysts were prepared through a facile method of refluxing. Thermogravimetric analysis (TG), powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM) were employed to characterize the as prepared α-Fe 2 O 3 /g-C 3 N 4 , which displayed distinguished cataluminescence (CTL) properties in the process of detecting H 2 S gas. When the α-Fe 2 O 3 content in the composite reaches 5.97%, the most outstanding CTL responses are observed. Under the optimized conditions, the linear detection range of the H 2 S gas sensor was 0.88–7.01 μg mL −1 ( r = 0.998) with the detection limit of 0.5 μg mL −1 ( S / N = 3). Furthermore, the H 2 S gas sensor showed superior selectivity to H 2 S gas compared with other fourteen kinds of common volatile organic compounds (VOCs), as well as fast response (0.1 s) and recovery (0.6 s). These properties render α-Fe 2 O 3 /g-C 3 N 4 composite promising candidate for applications in various fields. [ABSTRACT FROM AUTHOR]

Cataluminescence (CTL) emitted on the surface of solid materials during a catalytic reaction is a very interesting phenomenon, which gives a novel, powerful tool for chemical analysis. Nanomaterial-assisted CTL is a promising transduction principle for gas sensing, and its main features of high sensitivity and long lifetime are also favorable for developing a wide array of analytical devices. This review summarizes advances in nanomaterial-assisted CTL methodologies, including the working mechanism, exploration of sensing materials, innovations in strategy and instrumentation, new types of CTL-based sensing system, and their application to analysis of complex gases and volatile organic compounds. Finally, we discuss some critical challenges and prospects in this field. [ABSTRACT FROM AUTHOR]

Abstract: In the present work, Y-doped metal-organic framework-5 (MOF-5) was synthesized by a simple solvothermal method and characterized by X-ray diffraction, scanning electron microscope, energy dispersive X-ray spectroscopy and nitrogen adsorption–desorption measurements, and firstly used as gas sensor materials based on cataluminescence (CTL). When isobutanol passed through the surface of the material, CTL emission was observed. The luminescence characteristics and optimal parameters were investigated in detail. Under the optimized conditions, the present gas sensor exhibited a linear range of 6.4–80.1mgL−1 toward isobutanol and with a limit of detection of 3.7mgL−1. The designed CTL sensor based on Y-doped MOF-5 shows no or weak sensing performance for foreign common volatile organic compounds. Moreover, compared with pure MOF-5, Y-doped MOF-5 exhibited a better CTL response to isobutanol under the same conditions. This work exploits a new application domain of metal-organic frameworks (MOFs). [Copyright &y& Elsevier]

In the present work, two-dimensional (2D) transition metal dichalcogenides (TMDs) WS 2 nanosheets, which was synthesized through simple ultrasonic-assisted liquid exfoliation, was used for constructing H 2 S CTL gas sensor for the first time. With respect to other H 2 S CTL gas sensors based on metal oxides and metal-free materials, this sensor based on WS 2 nanosheets is outstanding in H 2 S sensing with excellent properties at relative low temperature of 187 ℃. Furthermore, both of the response and recovery time are as fast as 0.2 s with linear range of 0.26–6.38 µg mL−1 (R2 =0.9933) and detection limit of 0.06 µg·mL−1 (S/N = 3). The characterization results showed that as-prepared WS 2 nanosheets had larger surface, richer edges and more sulfur defects by comparing with bulk WS 2 , which are beneficial for catalytic performance improving. Importantly, the possible mechanism is proposed. In detail, some amount of WO 3 were in-situ generated forming WS 2 /WO 3 hybrids, and WO 3 could keep exchange balance with WS 2 during H 2 S sensing attributed to repeatable S-O bonding exchange. This is crucial for the repeatability of the sensor. This work provides a new view for CTL gas sensing mechanism and may open a new avenue of applying TMDs in H 2 S CTL sensors. • Two-dimensional WS 2 nanosheets was applied to build H 2 S CTL sensor for the first time. • With respect to other H 2 S CTL sensors, this sensor not only reduce the sensing temperature as low as 187 ℃, but also overcome the drawback of poisoning of sulfur compounds. • The mechanism study showed WO 3 were in-situ generated and balanced coexist with WS 2 during H 2 S sensing may due to the repeatable O-S binding exchange, which is crucial to sensor repeatability. [ABSTRACT FROM AUTHOR]

[Display omitted] • ZnMn 2 O 4 nanomaterial was firstly used in cataluminescence sensor. • The novel sensor exhibited excellent selectivity and high sensitivity toward H 2 S. • The cataluminescence sensing mechanism of H 2 S on ZnMn 2 O 4 -0.3 was further explored using density functional theory. Regarded as a highly toxic pollutants, H 2 S can severely threaten human health. Therefore, it is critical to develop an efficient sensing material to detect H 2 S gas. In this study, three nanomaterials—ZnMn 2 O 4 , ZnMn 2 O 4 -0.3, and ZnMn 2 O 4 -0.6—were successfully prepared via a simple hydrothermal method that is modified by the use of carbon spheres, and then applied to the field of cataluminescence (CTL). The nanostructure, surface composition, and morphology of the prepared catalysts were characterized via X-ray diffraction analysis, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy and transmission electron microscopy. Among the nanomaterials, ZnMn 2 O 4 -0.3 exhibited the highest CTL properties, including excellent H 2 S selectivity, because of its high content of surface-adsorbed O 2. Under optimized detection conditions, a good linear relationship (r = 0.997) of CTL intensity versus H 2 S concentration was obtained in the linear range of 0.810 – 26.3 μg mL−1, and the detection limit (S/N = 3, DL) was 0.405 μg mL−1. In addition, the CTL sensing mechanism for H 2 S on the ZnMn 2 O 4 -0.3 material was explored using the density functional theory. In comparison with previously reported various sensors based on CTL for H 2 S determination, ZnMn 2 O 4 -0.3 exhibited properties similar to or higher than other materials because of its low working temperature, fast response, and low DL, thereby confirming that ZnMn 2 O 4 can be used as a material for CTL detection of H 2 S. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, we presented a carbon tetrachloride gas sensor with strong cataluminescence response based on Ag2Se nanomaterial, which was synthesized via the electrodeposition on the surface of Al foil by directly using a non-aqueous dimethyl sulfoxide (DMSO) solution with CH3COOAg and SeCl4. The deposited Ag2Se material was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Then, the prepared Ag2Se material along with the Al foil substrate was employed to design the carbon tetrachloride gas sensor. Under the optimized conditions, the present gas sensor exhibited a broad linear range of 0.9–228μgmL−1, with a limit of detection of 0.3μgmL−1 (S/N=3). The proposed gas sensor showed good characteristics with high selectivity, fast response and long lifetime. [Copyright &y& Elsevier]

Abstract: This work proposed a gas sensor for the determination of tert-butyl mercaptan, one of the highly toxic volatile sulfur compounds, which was based on cataluminescence emission during its catalytic oxidation on the surface of nanosized V2O5. The cataluminescence characteristics and the optimum conditions, including the morphology of sensing material, the wavelength of cataluminescence emission, the oxygen flow rate and working temperature were investigated in detail. Under the optimized conditions, the calibration curve of the relative cataluminescence intensity versus the concentration of tert-butyl mercaptan vapor was made, with the linear range of 5.6–196μgmL−1 and the detection limit of 0.5μgmL−1 (S/N =3). The relative standard deviation (R.S.D.) (n =5) of relative cataluminescence intensity for 84μgmL−1 tert-butyl mercaptan was 3.6%. There is no or weak response to some common substances, such as formic acid, alcohol (methanol, ethanol, propanol, isopropanol, n-butanol, isoamyl alcohol), o-dichlorobenzene, acetonitrile, ethyl acetate, aldehyde (formaldehyde, acetaldehyde and propanal), 1,2-dichloroethane and ammonia. Furthermore, the proposed sensor was successfully used for determining tert-butyl mercaptan in four artificial samples, with a good recovery. The results demonstrated that the proposed gas sensor had a promising capability for the tert-butyl mercaptan in routine monitoring. [Copyright &y& Elsevier]

Abstract: In the present work, a novel and highly sensitive gas sensor for ethanol was demonstrated based on the intensive cataluminescence emission on the surface of YVO4:Eu3+ luminescent nanocrystals. By a hydrothermal synthesis process with surfactant (PEG 4000), the rice-like sensing material (YVO4:Eu3+) was successfully obtained. Considering the cataluminescence spectra and the fluorescence spectra of YVO4:Eu3+ nanocrystals, an energy transfer mechanism from excited intermediates to the YVO4:Eu3+ nanocrystals was proposed. Under the optimized conditions, the present gas sensor exhibited a linear range of 0.2–31.5μgmL−1, with a limit of detection of 0.03μgmL−1 (S/N=3). The proposed gas sensor showed good characteristics with fast response, high sensitivity and good stability. [Copyright &y& Elsevier]

Abstract: A novel and sensitive gas sensor was proposed for the determination of carbon tetrachloride based on its cataluminescence (CTL) by oxidation in the air on the surface of nanosized ZnS. The luminescence characteristics and the optimal conditions were investigated in detail. Under the optimized conditions, the linear range of the CTL intensity versus the concentration of carbon tetrachloride was 0.4–114μgmL−1, with a correlation coefficient (R) of 0.9986 and a limit of detection (S/N=3) of 0.2μgmL−1. The relative standard deviation (R.S.D.) for 5.9μgmL−1 carbon tetrachloride was 2.9% (n =5). There was no or weak response to common foreign substances including methanol, ethanol, benzene, acetone, formaldehyde, acetaldehyde, dichloromethane, xylene, ammonia and trichloromethane. There was no significant change of the catalytic activity of the sensor for 40h over 4 days, with a R.S.D. of less than 5% by collecting the CTL intensity once an hour. The proposed method was simple and sensitive, with a potential of detecting carbon tetrachloride in environment and industry grounds. The possible mechanism was also discussed briefly. [Copyright &y& Elsevier]

Abstract: When carbon disulfide (CS2) was passing through the surface of nanosized-CeO2 (nano-CeO2), strong chemiluminescence (CL) emission was observed. Based on this phenomenon, a novel sensitive gas sensor was demonstrated for the determination of CS2. The luminescence characteristics and optimal parameters, such as the morphology of the CeO2, wavelength, temperature and the flow rate of carrier gas, were investigated in detail. Under the optimal conditions, the CL intensity versus the concentration of CS2 was linear in the range of 0.9–12.6μgmL−1, with a linear correlation coefficient (R) of 0.999 and a limit of detection (S/N=3) of 3.7ngmL−1 for CS2. The relative standard deviation (R.S.D.) for the determination of 3.6μgmL−1 CS2 was 1.2% (n =5). There is no or weak response to foreign substances, such as alcohol (methanol, ethanol, and n-butanol), aldehyde (formaldehyde and acetaldehyde), acetone, ethyl acetate, chloroform, carbon tetrachloride, toluene, chlorobenzene, hexane and hydrogen sulfide. The stability and durability of the sensor were examined by sampling 7.2μgmL−1 CS2 vapor into the sensor everyday for 3h over two weeks, with a long-term R.S.D. of less than 6.0%. Finally, the proposed sensor was applied to the determination of CS2 in artificial air samples. [Copyright &y& Elsevier]

As a catalyst widely used in industry, manganese dioxide (MnO 2) has different crystalline forms and shows excellent performance in catalytic reactions. Therefore, it is of significance to rapidly evaluate the catalytic performance of MnO 2 online. In this paper, a highly efficient evaluation method based on H 2 S cataluminescence (CTL) sensing was proposed for MnO 2 with different crystalline forms. Firstly, α-, β- and δ-MnO 2 were synthesized successfully and performed diacritical CTL behaviours in the catalytic oxidation of H 2 S. Based on these interesting phenomena, the catalytic performance of α-, β- and δ-MnO 2 was efficiently evaluated online through CTL method for the first time. Results showed that β-MnO 2 had the best catalytic oxidation performance, followed by α- and δ-MnO 2 , and the reactive oxygen species of MnO 2 was the most significant influencing factor. Subsequently, β-MnO 2 was selected to design a CTL sensor for H 2 S detection with a wide linear range (2.43–29.1 μg/mL) and a low limit of detection (LOD, S/N = 3, 0.280 μg/mL). This work not only provided a new and feasible method for online evaluation of the catalytic performance of materials, but also designed a CTL sensor for H 2 S determination with high selectivity and sensitivity. [Display omitted] • Cataluminescence was employed to evaluate materials and screen catalysts efficiently. • The correlation between structures and catalytic performances of MnO 2 was firstly investigated using H 2 S as the model gas. • β-MnO 2 was firstly selected to build a H 2 S CTL sensor with high sensitivity and selectivity. [ABSTRACT FROM AUTHOR]

Abstract: In the present paper, a highly sensitive and selective sensor for acetone was demonstrated, which was based on intensive cataluminescence (CTL) emission on the surface of nano-sized La2O3. The CTL characteristics and the optimum conditions for the sensor, including La2O3 morphology, wavelength, working temperature, and airflow rate, were investigated in detail. Under the optimized conditions, the CTL intensity versus concentration of acetone was linear in the range of 0.19–140μgmL−1, with a correlation coefficient (r) of 0.9981 and a detection limit (signal-to-noise ratio is 3; and noise is the width of baseline) of 0.08μgmL−1. The relative standard deviation (R.S.D.) for 9.3μgmL−1 acetone (n =5) was 1.4%. There was no or weak response to common foreign substances, such as ammonia, toluene, benzene, formaldehyde, ethanol, methanol, ethyl acetate, and acetaldehyde. The gas sensor also exhibited good stability and durability for continuously introducing 19μgmL−1 acetone for 80h over 8 days, with a long-term R.S.D. less than 5%. [Copyright &y& Elsevier]

Abstract: A novel gas sensor for the determination of ethanol was proposed in the present work, which was based on the generated cataluminescence emission from catalytic oxidation of ethanol on the surface of ZnO nanoparticles. The cataluminescence characteristics and the effect of different parameters on the signal intensity, such as morphology of synthesized ZnO, temperature and flow rate, were discussed in detail. Under the optimized experimental conditions, the calibration curve of cataluminescence intensity versus ethanol vapor concentration was linear in the range 1.0–100ppm, and with a detection limit of 0.7ppm (S/N=3). Compared with the traditional electrical conductivity-based ZnO gas sensor for the determination of ethanol, the proposed ethanol sensor showed the advantages of high sensitivity, high selectivity and low working temperature. [Copyright &y& Elsevier]

[Display omitted] • Fluorine functionalized graphitic carbon nitride (F-g-C 3 N 4) was successfully synthesized under mild and simple conditions. • F-g-C 3 N 4 -based CTL sensor exhibits lower LOD than metal-free-based sensors and equivalent sensitivity of metal-based sensors. • The CTL mechanism of H 2 S on F-g-C 3 N 4 and the role of fluorine were deeply explored by experiments and DFT. Graphitic carbon nitride, as an excellent metal-free catalyst, is a promising candidate for cataluminescence (CTL) sensing of H 2 S owing to its high sulfur tolerance, environmental friendliness and low cost. Herein, in view of inner chemical inertness and low special surface area of g-C 3 N 4 , fluorine with strong electronegativity was employed to adjust the electron density of g-C 3 N 4 to obtain fluorine functionalized graphitic carbon nitride (F-g-C 3 N 4) for H 2 S sensing. As expected, the CTL response of F-g-C 3 N 4 exhibits more than 30 times higher towards H 2 S by contrast with that of g-C 3 N 4. Results demonstrated that F-g-C 3 N 4 was more conducive to the adsorption of O 2 and H 2 S due to the enlarged special surface area, the easier formation of hydrogen bond and the changed electronic structure, which was also supported by density functional theory calculations. Additionally, the F-g-C 3 N 4 -based sensor exhibits as high sensitivity as that of metal catalyst-based sensors but a longer lifetime. Meanwhile, the F-g-C 3 N 4 -based sensor has much higher CTL responses in the range of 1.27∼64.00 μg mL−1, lower detection limit of 0.07 μg mL−1 when comparing with previously reported metal-free catalyst-based sensors. Undoubtedly, this work not only opened up a novel approach to improve the sensing performance of g-C 3 N 4 , but also proposed an efficient strategy for obtaining satisfying catalytic performance of other metal-free layered materials. [ABSTRACT FROM AUTHOR]

• Porous boron nitride (p-BN) as a novel metal-free cataluminescence material was firstly applied in H 2 S. • The proposed CTL sensing platform displayed outstanding response to H 2 S with high sensitivity, selectivity and stability. • A possible mechanism about the interface reaction between BN and H 2 S was explored. As a highly toxic gas, hydrogen sulfide (H 2 S) poses risks in terms of environmental and human health. It is mandatory to investigate sensing materials for high performance H 2 S sensing. Compared with typically metal materials, metal-free materials show significant advantages in its low-cost, environmentally friendliness as well as stability, which attract more and more attentions in recent years. In this study, with Zinc (Zn) salt as a co-reagent, a two-dimensional metal-free material, porous boron nitride (p-BN) was synthesized and a novel metal-free cataluminescence (CTL) gas sensor was fabricated. By virtue of high specific area and B-vacancies on BN, the as-prepared p-BN gas sensor showed a rapid, stabile, sensitive and selective response toward H 2 S, with a wide linear range from 2.79 to 178.6 μg mL−1 and a low limit detection of 0.52 μg mL−1. Meanwhile, the mechanism was also discussed in detail. The study opens an attractive perspective of BN as metal-free materials for high performance toxic gases sensing. [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]

• A novel photocatalysis enhanced cataluminescence (CTL) gas sensor with metal-free catalyst for CO was developed. • PDINH 50 -50, a metal-free catalyst was used as the sensing material in CTL for the first time. • Photocatalysis assisted gas sensor showed the enhanced sensitivity of CO. The rapid and sensitive detection techniques for CO are highly essential for public health and environmental pollution. Herein, a photocatalysis enhanced cataluminescence (CTL) gas sensor with metal-free catalyst for CO was developed. Due to the low CTL reaction activity of CO, photocatalysis which could activate CO was chosen as effective signal amplification technology to improve response sensitivity of CO. Meanwhile, self-assembled 3,4,9,10-Perylenetetracarboxylic Diimide (PDINH), which has stacked ordered structure with π-π stacking, was first used as metal-free catalyst for CO oxidation in CTL process. The π-π stacking and layered structure in PDINH are beneficial for the adsorption of O 2 and CO. Therefore, amplified CTL signal was acquired because of the important role of photocatalysis and the sensing material in CTL process. Under the optimal experimental conditions, a detection limit (3σ) of 0.002 μg mL−1 CO is found in the proposed method, which has been further improved comparing to that of without photocatalysis. The realization of combining photocatalysis with CTL for the first time gives us a perspective on building a new pretreatment strategy for CTL detection. [ABSTRACT FROM AUTHOR]

• A highly efficient CTL sensor for acetone vapor coupled with UIO-66 as the preconcentrator was established. • A simple and low-cost home-made adsorption apparatus with UIO-66 was fabricated. • The proposed CTL sensing platform demonstrated advantages of high sensitivity, selectivity, and speediness. Metal-organic frameworks (MOFs) showed a significant sorption potential in the gas capture and preconcentration during recent years because of its super porosity. Herein, we fabricated a simple and inexpensive home-made adsorption apparatus based on UIO-66 as the preconcentrator, which was firstly coupled with a rapid cataluminescence (CTL) sensor to determine acetone vapor. The CTL emission was enhanced by 25 times after the preconcentration of UIO-66, indicating the UIO-66 preconcentrator could efficiently ameliorate sensitivity. As for the adsorption mechanism of UIO-66 for acetone molecules, we deduced that acetone molecules were preferentially located on the Zr clusters with high hydrophilicity. The proposed CTL sensor in combine with UIO-66 adsorption granted a detection limit of acetone down to 2.79 ppm, and demonstrated good selectivity, simplicity, rapidity, and recyclability. This study provides appealing perspectives of UIO-66 as the preconcentrator for the improvement of analytical performance, and the prospect of a miniaturized portable acetone sensor. [ABSTRACT FROM AUTHOR]