ABSTRACT
Chlorophenol and Congo Red dye being highly toxic are well known for their carcinogenic activity. This work focuses on preparing an organogel for the removal of both chlorophenol and Congo Red. PAni molecules were grafted in situ between the layers of montmorillonite (MMT) to form a PAni/MMT composite, which was further modified to form a gel structure. The composite was thoroughly characterized by high-resolution X-ray diffraction (HR-XRD), Fourier transform infrared (FT-IR) analysis, Brunauer-Emmett-Teller (BET) analysis, and thermogravimetric analysis (TGA). The gel was further analyzed by scanning electron microscopy (SEM) and by studying the rheological properties. The resulting gel exhibited an impressive solvent uptake, with a maximum of 2084% (20 times) for chlorophenol, while the dye adsorption capacity was 349.72 mg/g with 99.44% removal efficiency. The adsorption proceeded with the pseudo-second-order model followed by the Langmuir monolayer adsorption model and Weber's intraparticle diffusion model. The sorbent was found to be selective among cationic dyes while retaining 83% of dye even in the fifth cycle. The hybrid sorbent shows great promise for sustainable purposes, and the results of this study are certainly encouraging.
ABSTRACT
The impressive photoluminescence properties of all inorganic cesium lead halide perovskite quantum dots (PeQDs) make them highly intriguing for fluorescence chemosensor applications. Herein, a ratiometric dual emitting perovskite-based sensor was designed by synthesizing fluorescent CsPbBr3 PeQDs in situ within a matrix of Eu-BDC (Eu(III) benzene-1,4-dicarboxylate). The results presented here establish the suggested sensor's quick and selective turn-on PL response to volatile primary aliphatic amine derivatives. In the presence of amines, the designed CsPbBr3/Eu-BDC sensor exhibits an enhancement of the PL signal of CsPbBr3 at 518 nm and the Eu-BDC signal at 615 nm served as a standard for constructing the ratiometric sensing system. Thereby, a visual color change from red to green was observed with the incremental addition of methylamine to the probe. A low detection limit of 0.083 ppm was determined for methylamine. In both the solution and vapor phases, this ratiometric sensor responds to a variety of primary aliphatic amines with very quick and strong fluorescence. Moreover, the sensor was effectively used for monitoring meat spoilage owing to the emission of biogenic amine vapor from meat products.
ABSTRACT
Inorganic halide-based perovskites (e.g., cesium lead bromide) are tremendously useful semiconducting materials due to their unique optoelectronic properties. However, degradation of these perovskites under humid conditions is one of the major drawbacks to prevent their wide applications. Herein, passivated cesium lead bromide nanoparticles are synthesized using p-thiocresol as a passivating ligand, and this stable version of perovskite is later applied successfully as a sensor probe towards cholesterol detection. The designed sensor can detect cholesterol with a lower detection limit of 0.24 ppm and a fast response time of 10 s. The mechanism of quenching PTC@CsPbBr3 upon the gradual addition of cholesterol is discussed. Further, the sensor is successfully applied in the detection of cholesterol in real samples (blood serum). This work presents PTC@CsPbBr3 as a novel sensing platform for detecting cholesterol well in biomedical applications.