In this study, heterostructured g-C3N4/Ag–TiO2 nanocomposites were successfully fabricated using an easily accessible hydrothermal route. Various analytical tools were employed to investigate the ...surface morphology, crystal structure, specific surface area, and optical properties of as-synthesized samples. XRD and TEM characterization results provided evidence of the successful fabrication of the ternary g-C3N4/Ag–TiO2 heterostructured nanocomposite. The heterostructured g-C3N4/Ag–TiO2 nanocomposite exhibited the best degradation efficiency of 98.04% against rhodamine B (RhB) within 180 min under visible LED light irradiation. The g-C3N4/Ag–TiO2 nanocomposite exhibited an apparent reaction rate constant 13.16, 4.7, and 1.33 times higher than that of TiO2, Ag–TiO2, and g-C3N4, respectively. The g-C3N4/Ag–TiO2 ternary composite demonstrated higher photocatalytic activity than pristine TiO2 and binary Ag–TiO2 photocatalysts for the degradation of RhB under visible LED light irradiation. The improved photocatalytic performance of the g-C3N4/Ag–TiO2 nanocomposite can be attributed to the formation of an excellent heterostructure between TiO2 and g-C3N4 as well as the incorporation of Ag nanoparticles, which promoted efficient charge carrier separation and transfer and suppressed the rate of recombination. Therefore, this study presents the development of heterostructured g-C3N4/Ag–TiO2 nanocomposites that exhibit excellent photocatalytic performance for the efficient degradation of harmful organic pollutants in wastewater, making them promising candidates for environmental remediation.
Room temperature (RT) synthesis of the ternary cesium lead bromide CsPbBr3 quantum dots with oleic acid and oleylamine ligands was developed by Zeng and coworkers in 2016. In their works, the ...supersaturated recrystallization (SR) was adopted as a processing method without requiring inert gas and high-temperature injection. However, the oleic acid ligand for haloplumbate is known to be relatively unstable. Hence, in this work, we employed the eco-friendly olive oil to replace the oleic acid portion for the SR process at RT. Resultantly, we found that the cube-shaped nanocrystal has a size of ~40–42 nm and an optical bandgap of ~2.3 eV independent of the surface ligands, but the photoluminescence lifetime (τav) and crystal packing are dependent on the ligand species, e.g., τav = 3.228 ns (olive oil and oleylamine; here less ordered) vs. 1.167 ns (oleic acid and oleylamine). Importantly, we explain the SR mechanism from the viewpoint of the classical LaMer model combined with the solvent engineering technique in details.
Recently, polymeric graphitic carbon nitride (g-C
N
) has been explored as a potential catalytic material for the removal of organic pollutants in wastewater. In this work, graphitic carbon nitride ...(g-C
N
) photocatalysts were synthesized using mixtures of low-cost, environment-friendly urea and thiourea as precursors by varying calcination temperatures ranging from 500 to 650 °C for 3 h in an air medium. Different analytical methods were used to characterize prepared g-C
N
samples. The effects of different calcination temperatures on the structural, morphological, optical, and physiochemical properties of g-C
N
photocatalysts were investigated. The results showed that rhodamine B (RhB) dye removal efficiency of g-C
N
prepared at a calcination temperature of 600 °C exhibited 94.83% within 180 min visible LED light irradiation. Photocatalytic activity of g-C
N
was enhanced by calcination at higher temperatures, possibly by increasing crystallinity that ameliorated the separation of photoinduced charge carriers. Thus, controlling the type of precursors and calcination temperatures has a great impact on the photocatalytic performance of g-C
N
towards the photodegradation of RhB dye. This investigation provides useful information about the synthesis of novel polymeric g-C
N
photocatalysts using a mixture of two different environmentally benign precursors at high calcination temperatures for the photodegradation of organic pollutants.
Recently, tuning the green emission of CsPbBr3 quantum dots (QDs) to blue through quantum size and confinement effects has received considerable attention due to its remarkable photophysical ...properties. However, the synthesis of such a blue-emitting QD has been challenging. Herein, supersaturated recrystallization was successfully implemented at room temperature to synthesize a broadband blue-emitting ZnBr2-doped CsPbBr3 QD with an average size of ~3 nm covering the blue spectrum. The structural and optical properties of CsPbBr3 QDs demonstrated that QD particle size may decrease by accommodating ZnBr2 dopants into the perovskite precursor solution. Energy-dispersive spectroscopy confirmed the presence of zinc ions with the QDs. This work provides a new strategy for synthesizing strongly quantum-confined QD materials for photonic devices such as light-emitting diodes and lighting.
The phase change of all-inorganic cesium lead halide (CsPbI3) thin film from yellow δ-phase to black γ-/α-phase has been a topic of interest in the perovskite optoelectronics field. Here, the main ...focus is how to secure a black perovskite phase by avoiding a yellow one. In this work, we fabricated a self-doped CsPbI3 thin film by incorporating an excess cesium iodide (CsI) into the perovskite precursor solution. Then, we studied the effect of organic additive such as 1,8-diiodooctane (DIO), 1-chloronaphthalene (CN), and 1,8-octanedithiol (ODT) on the optical, structural, and morphological properties. Specifically, for elucidating the binary additive–solvent solution thermodynamics, we employed the Flory–Huggins theory based on the oligomer level of additives’ molar mass. Resultantly, we found that the miscibility of additive–solvent displaying an upper critical solution temperature (UCST) behavior is in the sequence CN:DMF > ODT:DMF > DIO:DMF, the trends of which could be similarly applied to DMSO. Finally, the self-doping strategy with additive engineering should help fabricate a black γ-phase perovskite although the mixed phases of δ-CsPbI3, γ-CsPbI3, and Cs4PbI6 were observed under ambient conditions. However, the results may provide insight for the stability of metastable γ-phase CsPbI3 at room temperature.
Abstract
In the present study, a new biochemical biosensor material of conductive Silver (Ag) reinforced polyaniline (PANI)-Benzimidazole copolymer nanocomposite was fabricated via
in situ
chemical ...oxidative polymerization method for the detection of endotoxin. The fabricated PANI-Benz-Ag nanocomposite was characterized by FTIR, XRD, UV–visible spectrometer, DSC, TGA, Zeta-potential, SEM, TEM, and Confocal fluorescence imaging microscopy. The measured particle size, zeta-potential, and conductivity of the PANI-Benz-Ag nanocomposite were 4.942 nm, −10.4 mV, and 73.7
μ
S cm
−1
respectively. The crystallite size of Ag nanoparticles was around 67 nm calculated by XRD analysis and TGA analysis was carried out to determine weight loss and thermal stabilities of PANI-Benz and PANI-Benz-Ag nanocomposite. The endotoxin (
E. coli)
bacteria detection ability of the synthesized PANI-Benz-Ag nanocomposite-based biochemical biosensor using DMMB dye displacement assay through the hitchhiking method by confocal fluorescence microscopy was found to be simple and effective. Endotoxin
(E. coli)
can form a stable interaction with other bioactive molecules and thus it binds readily with Ag-doped PANI-Benzimidazole nanocomposite. Further, the DMMB dye displacement assay method is more accurate and sensitive than the other existing methods for the detection of endotoxin.
All-inorganic cesium lead bromide (CsPbBr3) quantum dots (QDs) have received a surge of attention in the field of light-emitting diode (LED) display and lighting. Hence, it is interesting to study ...the composite film composed of CsPbBr3 and light-emitting MDMO-PPV matrix polymer. In this study, we investigate the phase behavior among the components, MDMO-PPV, toluene (solvent), and oleic acid and oleylamine (the surface ligands for QDs) based on the Flory-Huggins theory with the group contribution method for the first time. Here we find that the MDMO-PPV and ligand molecules are immiscible whereas MDMO-PPV and toluene are partially miscible. Then through the x-ray diffraction (XRD) patterns, we demonstrate that CsPbBr3 QDs form a nanoscale domain with ∼33–52 nm crystallites in the MDMO-PPV matrix. Furthermore, the scanning electron microscope (SEM) images display that CsPbBr3 QDs can be highly aggregated at MDMO-PPV:CsPbBr3= 50:50 composition. Then, through the ultraviolet-visible (UV–vis) and photoluminescence (PL) spectra, the enhancement of PL intensity is observed at ∼30–50 wt% CsPbBr3. Finally, the electrochemical impedance spectra indicate that the composite film exhibits less resistance (∼3.2×104 Ω) than the pure MDMO-PPV film (∼1.4×107 Ω), suggesting that the MDMO-PPVCsPbBr3 composite approach is promising for electrochemical and optoelectronic applications.
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In this study, heterostructured g-C
N
/Ag-TiO
nanocomposites were successfully fabricated using an easily accessible hydrothermal route. Various analytical tools were employed to investigate the ...surface morphology, crystal structure, specific surface area, and optical properties of as-synthesized samples. XRD and TEM characterization results provided evidence of the successful fabrication of the ternary g-C
N
/Ag-TiO
heterostructured nanocomposite. The heterostructured g-C
N
/Ag-TiO
nanocomposite exhibited the best degradation efficiency of 98.04% against rhodamine B (RhB) within 180 min under visible LED light irradiation. The g-C
N
/Ag-TiO
nanocomposite exhibited an apparent reaction rate constant 13.16, 4.7, and 1.33 times higher than that of TiO
, Ag-TiO
, and g-C
N
, respectively. The g-C
N
/Ag-TiO
ternary composite demonstrated higher photocatalytic activity than pristine TiO
and binary Ag-TiO
photocatalysts for the degradation of RhB under visible LED light irradiation. The improved photocatalytic performance of the g-C
N
/Ag-TiO
nanocomposite can be attributed to the formation of an excellent heterostructure between TiO
and g-C
N
as well as the incorporation of Ag nanoparticles, which promoted efficient charge carrier separation and transfer and suppressed the rate of recombination. Therefore, this study presents the development of heterostructured g-C
N
/Ag-TiO
nanocomposites that exhibit excellent photocatalytic performance for the efficient degradation of harmful organic pollutants in wastewater, making them promising candidates for environmental remediation.
In this study, heterostructured g-Csub.3Nsub.4/Ag–TiOsub.2 nanocomposites were successfully fabricated using an easily accessible hydrothermal route. Various analytical tools were employed to ...investigate the surface morphology, crystal structure, specific surface area, and optical properties of as-synthesized samples. XRD and TEM characterization results provided evidence of the successful fabrication of the ternary g-Csub.3Nsub.4/Ag–TiOsub.2 heterostructured nanocomposite. The heterostructured g-Csub.3Nsub.4/Ag–TiOsub.2 nanocomposite exhibited the best degradation efficiency of 98.04% against rhodamine B (RhB) within 180 min under visible LED light irradiation. The g-Csub.3Nsub.4/Ag–TiOsub.2 nanocomposite exhibited an apparent reaction rate constant 13.16, 4.7, and 1.33 times higher than that of TiOsub.2, Ag–TiOsub.2, and g-Csub.3Nsub.4, respectively. The g-Csub.3Nsub.4/Ag–TiOsub.2 ternary composite demonstrated higher photocatalytic activity than pristine TiOsub.2 and binary Ag–TiOsub.2 photocatalysts for the degradation of RhB under visible LED light irradiation. The improved photocatalytic performance of the g-Csub.3Nsub.4/Ag–TiOsub.2 nanocomposite can be attributed to the formation of an excellent heterostructure between TiOsub.2 and g-Csub.3Nsub.4 as well as the incorporation of Ag nanoparticles, which promoted efficient charge carrier separation and transfer and suppressed the rate of recombination. Therefore, this study presents the development of heterostructured g-Csub.3Nsub.4/Ag–TiOsub.2 nanocomposites that exhibit excellent photocatalytic performance for the efficient degradation of harmful organic pollutants in wastewater, making them promising candidates for environmental remediation.
