In this study, flower-like MoS₂ nanomaterials were synthesized by hydrothermal method with excess thiourea. The adsorption performance of MoS₂ adsorbent for methylene blue (MB) in azo dye wastewater was studied. The morphology, crystal phase, and microstructure of nano MoS₂ samples were characterized by X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy, and Fourier transform infrared spectroscopy. The effects of adsorption isotherm, kinetics, different hydrothermal time, and pH on the adsorption experiment were studied. The results showed that the MoS₂ adsorbent with a hydrothermal time of 1 h had good adsorption properties for MB. The adsorption data accord with the Langmuir isotherm model, and the maximum adsorption capacity of MoS₂ adsorbent is 200 mg/g, and the adsorption kinetics agrees well with the pseudo two-level model. The removal rate of MB is not significantly affected by the pH values. The large pH range can still maintain the removal rate above 93.47%, and the regeneration and recovery properties of MoS₂ were also explored. Finally, the adsorption mechanism of MoS₂ on MB is discussed.

A CdS/SnS nanocomposite was prepared using a simple hydrothermal method and used as a sensitive material for the detection of carbon disulfide (CS₂) based on cataluminescence (CTL). The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive spectrometry (EDS) and X-ray photoelectron spectroscopy (XPS). The results show that the CdS/SnS nanocomposite sensor has a high sensitivity to CS₂ at a relatively low operating temperature (162 °C); the response time is about 3 s, and the recovery time is about 16 s. The modification of CdS effectively enhances the sensitivity of SnS sensors. The CTL intensity shows a good linear relationship at gas concentrations ranging from 6.75 to 168.75 ppm (R² = 09974), and the limit of detection (LOD) of CS₂ reached 0.96 ppm. In addition, the CdS/SnS sensor has excellent selectivity and good stability towards CS₂. The mechanism of the sensor is discussed in detail. This research shows that CdS/SnS has great potential for the detection of CS₂.

In this work, a series of clinoptilolite composites decorated with carbon quantum dots (CQDs/clinoptilolite) with hierarchical pore structures was demonstrated that exhibits good photocatalytic performance for the removal of xylene. The technique for the attachment of carbon quantum dots to clinoptilolite was prepared by a hydrothermal method in this study. The structural features were confirmed by SEM, TEM, EDS, XRD, BET, XPS, and solid diffuse reflection measurements, while the degradation mechanism was investigated by adding a trapping agent into the nanocomposites. The introduction of CQDs promoted the separation of photogenerated electrons and holes as well as the generation of reactive radicals, which effectively improved the light utilization and even increased the degradation rate of xylene by 73% at the optimal state. The photocatalytic test was conducted under a different dwell time, catalyst dosage, initial concentration, and illumination intensity. The results showed that the degradation rate of xylene by the CQDs/clinoptilolite catalyst reached 97.4% under the optimal reaction conditions (the catalyst was Catalyst No. 2, the residence time was 90 s, the initial concentration was 2.5 g/m³, the light intensity was three lamps for irradiation, and the catalyst dosage was 0.05 g). In addition, the degradation efficiency of the CQDs/clinoptilolite photocatalyst still reached 78% after eight consecutive catalytic regeneration cycles. This work sheds new light on the degradation of xylene.

Dichloromethane, as a widely used highly volatile industrial solvent, has neurotoxicity and hepatotoxicity and is suspected of being a carcinogen to humans. Therefore, it is necessary to develop a detection method that is more convenient for users, responds faster and is more efficient than traditional analytical techniques. In cataluminescence (CTL) technology, as a promising alternative, the performance of CTL sensors critically depends on the design of high-performance sensitive materials. In this study, by rationally designing two typical metal–organic frameworks (MOFs), UIO-66 (zirconium-based) and HKUST-1 (copper-based), UIO-66/HKUST-1 nanocomposites for dichloromethane CTL detection were prepared by using a simple hydrothermal method. The experimental results show that when the composition ratio of UIO-66 is 2%, this composite exhibits the strongest CTL response to dichloromethane. Under optimized conditions, this sensor exhibits high selectivity, excellent stability (RSD = 3.98%), and a rapid response advantage for dichloromethane. The response time and recovery time are 5 and 19 s, respectively. It shows a good linear relationship within the concentration range of 8.4–84 ppm, along with a detection limit as low as 1.71 ppm. Analysis indicates that the enhanced performance stems from the formation of high-concentration oxygen vacancies and significantly strengthened synergistic effects at the UIO-66/HKUST-1 composite. This increases the concentration of surface reactive oxygen species, thereby providing more active sites for catalytic reactions. This work provides a robust and efficient sensing strategy for dichloromethane detection.