Carbazole Research Articles

Polycyclic aromatic hydrocarbon derivatives onto polar microplastics of polyurethane: equilibrium, thermodynamics, and kinetics of monolayer-multilayer adsorption.

The study of the adsorption of polycyclic aromatic hydrocarbons on microplastics (MPs) has attracted much attention as to how microplastics can act as carriers of these pollutants. Polyurethane (PU) is one of the MPs found in aquatic environments, containing different functional groups it can interact with polar and nonpolar molecules. PAH derivatives (dPAHs) present different properties and thus can be adsorbed by different interactions; thus, this study investigated the adsorption of fluorene (FLN), dibenzothiophene (DBT), dibenzofuran (DBF), and carbazole (CBZ) onto PU MP. The Langmuir, Freundlich, and BET isotherm models were examined, and the BET model best fitted. The adsorption was a nonspontaneous process, exothermic for mono- and multilayer formation for FLN, DBT, and CBZ, and endothermic for DBF monolayer formation. The adsorption monolayer was formed by van der Waals forces, H─bonding, and π─π interactions, while the formation of the multilayer can be explained by π─π and hydrophobic interactions. The pseudo-second-order model proved to be more consistent for the adsorption of dPAHs. The adsorption in artificial seawater shows no significant differences for the monolayer but favored the adsorption multilayer due to the salting-out effect. Due to the existence of several adsorption mechanisms, PU MP interacts with dPAHs in greater quantities when compared to a MP with a simpler structure.

Preparation, structure and optical properties of TCNB-based charge-transfer cocrystals

Organic charge transfer cocrystals exhibit interesting properties due to their multi-components synergistic and collective effect. Herein, using 1,2,4,5-tetracyanobenzene (TCNB) as electron acceptor, carbazole (CARB), dibenzothiophene (DBZP) and dibenzofuran (DBZF) as electron donors, three charge transfer cocrystals of CARB-TCNB, DBZP-TCNB and DBZF-TCNB were synthesized by solvent evaporation method and solvent-assisted grinding method. These cocrystals were constructed based on the π–π stacking interactions and CH…N hydrogen bonds and confirmed by the SXRD analysis. The stacking modes are consistent with the model that predicted by molecular electrostatic potential analysis (ESP). The IGM and AIM analyses suggested that the π-π stacking and CH…N hydrogen bonds are weak in nature. The purity and homogeneity of cocrystals and grinding products were verified by PXRD analysis. In addition, the IR, UV–vis absorption and luminescent properties were investigated, and the cocrystals and grinding products exhibited different behaviors from that of their precures. In short, this work not only reports the CT complexes synthesized by liquid- and solid- strategies, but also provides an in-depth understanding of the spectral changes caused by the CT interactions.

Enhancing the performance of pyridyl carboxamide-N,N-dimethyl amino chalcone (PCC) as a dye sensitizer for dye-sensitized solar cells (DSSCs) through the incorporation of electron donor moieties

This study has focused on enhancing the performance of pyridyl carboxamide-N,N-dimethyl amino chalcone (PCC) as a sensitizer for dye-sensitized solar cells (DSSCs) by strategically incorporating electron donor moieties identified in a literature review. Our reviewing the previous reports highlights the pivotal role of electron donors in optimizing light harvesting, electron injection, and overall power conversion efficiency in organic dye sensitizers, particularly those following a donor-bridge-acceptor (D-π-A) architecture. The selected donor moieties, including dithieno[3,2-b:2′,3′-d]thiophene (DTT), benzodithiophene (BDT), triphenylamine (TPA), carbazole (CBZ), and triazatruxene (TAZ), are systematically introduced into the molecular structure of PCC (abbreviated as PCC-DTT, PCC-BDT, PCC-TPA, PCC-CBZ, and PCC-TAZ, respectively). The performance of these modified compounds is rigorously evaluated using density functional theory (DFT) methods. Validation results revealed that the most reliable method for PCC derivative characterization involved the combination of the functional B3PW91 with a 6-31G(d) basis set. The results indicate that the incorporation of certain donor moieties, particularly BDT, significantly enhances the electronic and optical properties of PCC, including lower HOMO energy levels, a narrow energy gap (Egap), enhanced absorption intensity, and a redshift in absorption peaks. Evaluation of photovoltaic properties including electron injection (ΔGinj), and open circuit voltage (Voc), indicated facilitating spontaneous electron injection from the dyes to the TiO2 conduction band. Notably, PCC-TAZ demonstrated the lowest electron regeneration (ΔGreg), suggesting a notable potential for efficient electron regeneration.

Use of nitrogen markers to assess source rock paleodepositional environment of the Candeias (Recôncavo Basin) and Barreirinha (Amazonas Basin) formations

In this study nitrogen markers (N-markers) were employed to evaluate the depositional paleoenvironment of the Candeias and Barreirinha Formations, Recôncavo and Amazonas Basins, respectively. Towards this end, twenty-one N-markers from carbazole (CA), benzocarbazole (BCA), indole (IND), acridine (ACR), and quinolone (QUIN) classes were determined by highly selective and sensitive gas chromatography-triple quadrupole mass spectrometry (GC–MS/MS). Twenty-four (24) samples was collected in vertical sections of outcrops of the Candeias Formation and of the Barreirinha Formation. The N-markers were efficient in evaluating distinctions and similarities between the source rocks and were able to define the origin and input of organic matter, the depositional paleoenvironment conditions of the samples. The samples from the Recôncavo Basin presented low concentrations of CA, methyl carbazole (MCA), and dimethyl carbazole (DMCA), and high concentrations of QUIN and 4-methyl quinoline (4-MQUIN), indicating a lacustrine environment. Samples from the Amazonas Basin present high concentrations of CA, MCA, DMCA, 2,4-dimethyl quinoline (2,4-DMQUIN), benzo[c]quinoline (B[c]QUIN), and ACR, typical of the marine environment. Although the formations are from different paleoenvironments, the organic matter input is similar. The proportions of the 1-, 2- and 4-methyl carbazole (1-MCA, 2-MCA, and 4-MCA), in addition to the low values for the 4-MCA/2-MCA ratio, allowed to affirm that algal input was predominant in the Candeias and Barreirinha formations. The relative concentration of DMCA and of the B[b]CA isomer also indicate the supply of terrigenous material for both formations. BCA concentrations were affected by the conditions of depositional paleoenvironment. Samples deposited under redox conditions presented low concentrations of BCA, and those deposited in oxidizing environments had higher amounts.

Novel D-π-A hemicyanine dye as photoinitiators for insitu hydrogel formation and DLP printing.

The field of biofabrication imposes stringent requirements on the polymerization activity and biosafety of photopolymeric hydrogel systems. In this investigation, we designed and synthesized four hemicyanine dyes with a D-π-A structure specifically tailored for biofabrication purposes. These novel dyes, incorporating carbazole (CZ), triphenylamine (TPA), anthracene (AN), and benzodithiophene (BDT) as electron donors, along with heterocyclic salt (IN) as electron acceptors, were prepared using a straightforward synthesis method. The absorption maxima of ANIN, CZIN, and TPAIN exceeded 500 nm, rendering them suitable co-initiators for the free radical photopolymerization of acrylates under green-red light exposure facilitated by light-emitting diodes (LEDs) and the co-initiator iodonium salt (ION). Notably, CZIN and TPAIN, due to their robust dye absorption and efficient electron transfer to ION, functioned as high-performance photosensitizers. Meanwhile, BDTIN, with its strong and broad absorption range (400-600 nm), enhanced the accuracy of visible light photopolymerization. These dyes exhibit characteristics such as facile synthesis, heightened photo stability, and non-toxicity and also demonstrate the ability to discern the alkalinity of a solution to some extent. Furthermore, we explored the application of these hemicyanine dyes in 3D printing, showing potential to enhance printing resolution in DLP 3D printing (digital light process 3D printing).

Intriguing Role of Weak Electron Donor in Dictating the Luminescent Characteristics of DS‐A‐DW Materials

AbstractThe short wavelength (SW) emission region of the materials employing strong donor (DS) phenothiazine (PTZ) is generally correlated to its quasi‐axial (QAPTZ) conformer arrangement. This propels to investigate the specific role of weak donors (DW) such as carbazole (CZ) in determining the emission characteristics of molecular heredity (MH) type structural design encompassing dual donors of varying strength. For this purpose, a common DS(PTZ)–Acceptor unit is linked to the DW(CZ) unit via different linkage positions to form M1, M2, and M3, which not only alters the absorption and dual emission characteristics but also influences the delayed fluorescence phenomenon. The SW emission originates by minimizing the aggregation factor rather than by literature envisaged QAPTZ conformer. Incorporating M1 as a single molecular white light emitter (SMWLE) in near UV light emitting diode (LED) devices results in cold white light emission with CRI of 68 and CIE of (0.24, 0.33), while its corresponding solution‐processed organic light‐emitting diode devices delivers warm white electroluminescence with an EQE of 5.8%. Overall, this work demonstrates the significant contribution of the DW in attaining the white light emission characteristics of MH molecular design not only at the molecular level but also in practical light‐emitting devices.

The effects of co-existing acridine on adsorption-desorption behavior of carbazole in soils: Co-sorption and mechanism insight

Carbazole (CBZ) and acridine (ACR) are polycyclic aromatic nitrogen heterocycles (PANHs) widely found in combined contaminated soils, while investigations on organic-organic interactions have been very limited. In this study, batch experiments were carried out on five soils with different properties, taking CBZ as a representative of PANHs and ACR as a co-existing contaminant. The adsorption isotherms of CBZ (50–1000 μg/L) were nonlinear. Soil organic matter (SOM) and cation exchange capacity (CEC) showed positive correlations with CBZ adsorption-desorption coefficients. The adsorption mechanisms of CBZ involved hydrogen bonding, π-π interaction, and cation-π bonding. Different concentrations of ACR had varying effects on CBZ. The adsorption of CBZ was inhibited with 250 μg/L ACR. The cooperative adsorption was observed on three soils with increasing ACR concentration (1000 μg/L) and led to more pronounced nonlinear isotherms. The S-shaped isotherms of ACR indicated that ACR was adsorbed to the soil surface in a perpendicular configuration. New adsorption sites were created allowing for increased CBZ adsorption through π-π interaction with ACR. Therefore, variations in soil properties and potential impacts of co-existing contaminants should be well considered when assessing the combined pollution of site soil. This will contribute to a more accurate estimation of environmental and health risks.

Calixarenes and cyclodextrins as off- and on-fluorescence probes for carbazole

Absorption and fluorescence spectra of the nitrogen polycyclic aromatic hydrocarbon carbazole (CZL) were analyzed with native cyclodextrins (CD; α, β, γ); derivatized CD (hydroxypropyl-β-cyclodextrin, HPCD; methyl-β-cyclodextrin, MeCD) and p-sulfonated calixarenes (SCAn, with n = 6 and 8) macrocycles. The results showed a slight increase in the absorbance of CZL with CD, but the mixture of CZL with SCA showed lower absorption than the sum of the individual spectra. Also, changes in fluorescence were observed by adding the macrocycles, quenching with SCA, and significant increases with CD. The higher fluorescence enhancement was with HPCD rationalized as a complex formation with 1:1 stoichiometry, with an average value for the association constant (K A ) of (12 ± 1) x 102 M−1, and a quantum yield ratio between the complexed CZL and free CZL (ΦCZL-HPCD/ΦCZL) of (1.56 ± 0.02) at neutral pH and 25.0 °C. These increases in fluorescence were used as an on-fluorescence switch to develop a supramolecular analytical method for CZL in aqueous samples. The best analytical parameters were in HPCD (LOD = 1.41 ± 0.01 ng mL−1). The method was validated in aqueous samples of river and tap water with recoveries between 96%–104%. The proposed supramolecular method is quick, direct, selective and represents an alternative and low-cost analysis method.

Influence of thermal maturity on carbazole distributions in coal source rocks during compaction pyrolysis experiments

Carbazole compounds are widely used in determining the direction of petroleum migration, but the effect of thermal maturity on carbazoles is still ambiguity. In this paper, using compaction pyrolysis simulation experiments, artificial mature samples with vitrinite reflectance (Ro) range from 0.38 to 3.0% were acquired. And the content and composition change characteristics of carbazole compounds were analyzed in coal source rocks. The experimental results showed that thermal maturity controls the generation of a large amount of carbazole compounds in coal rocks. Compared with the low mature stage, the content of carbazole compounds was about 10–100 times higher in the mature stage. With the increasing maturity, in the coal sample, the content of carbazole compounds showed a trend of first increasing and then decreasing. In derivatives of carbazole, the corresponding maturity for the maximum generation of ethylcarbazole (EC), dimethylcarbazole (DMCA), methylcarbazole (MCA), carbazole (CA) and benzocarbazole (BCA) performed the increasing sequence. With the increasing maturity, the relative abundance of 2-MCA, 1,7-DMCA and benzo[a]carbazole increased with the increasing maturity, while 4-MCA, 1,4-DMCA and benzo[c]carbazole gradually decreased. Benzocarbazole ratio [a]/[a] +[ c] varies only in a narrow range 0.36–0.61 in the entire maturity range, suggesting limited maturity dependence. The experimental conclusion provides more theoretical basis for future geochemical analysis using carbazole compounds.

Presence of carbazole and polyhalogenated carbazoles in human urine

Exposure to carbazole (CZ) and polyhalogenated carbazoles (PHCZs) may pose a threat to human health, owing to their potential dioxin-like toxicity. Until now, the presence of these chemicals in the human urine from the general population is still unclear. Human urine samples (n = 210) were taken from the general population in Quzhou, China in this study, and were analyzed for CZ and 14 PHCZs. CZ and nine PHCZs were detected in collected human urine. CZ (detection frequency 100 %), 3-chlorocarbazole (3-CCZ; 88 %), 3,6-dichlorocarbzole (36-CCZ; 84 %), and 3-bromocarbazole (3-BCZ; 80 %) were more frequently detected. Among detected PHCZs, 3-CCZ (mean 0.49 ng/mL, < LOD–4.3 ng/mL) had comparatively higher urinary levels, followed by 3-BCZ (0.30 ng/L, < LOD–1.9 ng/mL) and 36-CCZ (0.20 ng/L, < LOD–1.4 ng/mL). Urinary concentrations of CZ in male participants (1.3 ± 0.26 ng/mL) were significantly (p < 0.05) higher than that in female participants (0.92 ± 0.24 ng/mL). No obvious trend in urinary concentrations with the age of participants was found for CZ and detected PHCZs. The mean daily excretion was found highest for CZ (31 ng/kg bw/day), followed by 3-CCZ (19 ng/kg bw/day) and 3-BCZ (8.5 ng/kg bw/day). This study provides the first data, to our knowledge, on the presence and levels of CZ and PHCZs in human urine, which is necessary for conducting the human exposure risk assessment.

High enrichment and measurement of heterocyclic aromatic hydrocarbons from environmental waters with magnetic resorcinol-formaldehyde nanocomposites coupled with high performance liquid chromatography

Heterocyclic aromatic hydrocarbons are concerned pollutants with carcinogenic toxicity, which exist universally in various environmental matrices and have great harm to environmental and human health. In present work, magnetic resorcinol-formaldehyde composites (Fe3O4@SiO2@R–F) were fabricated via aldol condensation reaction under alkaline condition. The prepared magnetic materials were examined and analyzed with Fourier transform infrared spectroscopy and other related instruments. The Fe3O4@SiO2@R–F composites were utilized to develop an efficient magnetic solid phase extraction (MSPE) method for extracting six heteropolyclic aromatic hydrocarbons from environmental water samples including carbazole (CB), 7-methylquinoline (7-MQL), 9-methylcarbazole (9-MCB), dibenzothiophene (DBT), 4-methyldibenzothiophene (4-MDBT), and 4,6-dimethyldibenzothiophene (4,6-DMDBT). The analytes were analyzed by high performance liquid chromatography-ultraviolet variable wavelength detector (HPLC-VWD). The main factors affecting MSPE were optimized. With the optimal parameters, 9-MCB and 4-MDBT have good linearity over the concentration range of 0.1–300 μg L−1, and 7-MQL, CB, DBT and 4,6-DMDBT have good linearity over the concentration range of 0.5–300 μg L−1. The limits of detection were over the concentration range of 0.012–0.031 μg L−1. This method was successfully employed to measure real waters, and the spiked recoveries ranged from 89.4% to 99.9%. The results confirmed that the developed method was reliable, robust and could be employed as a usefully alternate way for analyzing such pollutants in waters.

Small molecular donor materials based on β-β-bridged BODIPY dimers with a triphenylamine or carbazole unit for efficient organic solar cells.

Herein, we have designed and synthesized two novel BODIPY dimer-based small molecules, denoted as ZMH-1 and ZMH-2, covalently linked and functionalized with triphenylamine (TPA) (ZMH-1) and carbazole (CZ) (ZMH-2) units as the electron donor at the 3- and 5-positions of the BODIPY core, respectively. Their optical and electrochemical properties were investigated. We have fabricated all small molecule bulk heterojunction organic solar cells using these BODIPY-based small molecules as electron donors along with fullerene derivative (PC71BM) and medium bandgap non-fullerene acceptor IDT-TC as electron acceptors. The optimized OSCs based on ZMH-1:PC71BM, ZMH-2:PC71BM, ZMH-1:IDT-IC, and ZMH-2:IDT-IC attain overall PCEs of 8.91%, 6.61%, 11.28%, and 5.48%, respectively. Moreover, when a small amount of PC71BM as guest acceptor is added to the binary host ZMH-1:IDT-TC and ZMH-2:IDT-TC, the ternary OSCs based on ZMH-1 and ZMH-2 reach PCEs of 13.70% and 12.71%, respectively.

Occurrence of polyhalogenated carbazoles and the combined effects with heavy metals on variation in bacterial communities in estuarine sediments

Carbazole (CZ) and eight polyhalogenated carbazoles (PHCZs) were quantified by GC–MS in sediments of 12 estuaries, the interface linking large industrial and living areas to the Bohai Sea, China. These pollutants, heavy metals, and environmental factors caused integrated exposure to sediment bacteria. Four PHCZ congeners were detectable, with ΣPHCZs ranging from 0.56 to 15.94 ng/g dw. The dominant congeners were 3,6-dichlorocarbazole (36-CCZ) and 3-chlorocarbazole (3-CCZ), with a mean contribution of 72.6 % and 20.2 %. Significant positive correlations were found between 36-CCZ and both total organic carbon and heavy metals. Redundancy analysis of microbial variation implicated no impacts from PHCZs. Correlation analysis demonstrated an increase in abundance of Rhodocyclaceae but a decrease in Bacteroides-acidifaciens-JCM-10556 with presence of PHCZs, suggesting that these bacteria can be used as potential contamination indicators. The combined exposure of heavy metals, nutrients, and PHCZs may also increase toxicity and biological availability, adversely affecting the ecosystem and human health.

Improved heterocyclic aromatic hydrocarbon compound adsorption using functionalised rice husk biochar

Carbazole (CBZ) is a hazardous heterocyclic aromatic hydrocarbon (HAH) that pollutes water bodies, and the treatment remains a challenge due to its high persistence in the environment. This study chemically modified rice husk biochar (RHB) with starch derivative (DS) to develop an effective adsorbent. Thus, functionalised RHB with starch derivative (RHBDS) was synthesised to remove CBZ from synthetic wastewater. Based on a Box-Behnken design, the DS functionalisation optimisation was successfully performed. The parameters, including RHB mass of (5–10) g, DS concentration of (1–5)% w/v, and sonication period of (1–5) min, were analysed using Design Expert. These parameters were then utilised to investigate the optimal conditions (removal rate response and adsorption capacity) for the adsorbent. The removal rate and the adsorption capacity ranged from 83.85 to 98.94 % and 335.41 to 395.76 mg/g, respectively. Consequently, the RHB mass of 6.50 g, DS concentration of 1 % w/v, and sonication period of 5 min within the experimental domain exhibited the best conditions with desirability of 1.0. The 92.67 % removal rate and adsorption capacity of 370.59 mg/g were also obtained under optimal conditions. Compared to RHB, RHBDS demonstrated four times the adsorption capacity for the CBZ removal from synthetic water, which were 23.03 mg/g and 98.01 mg/g, respectively. Therefore, the RHBDS compound could be a promising adsorbent in removing CBZ from wastewater.

Crystal growth, HOMO-LUMO engineering and charge-transfer emission of TCNB-based donor-acceptor cocrystals

Using carbazole (CARB), dibenzothiophene (DBZP) and dibenzofuran (DBZF) as electron donors, 1,2,4,5-tetracyanobenzene (TCNB) as electron acceptor, three typical types of luminescent organic cocrystals were synthesized by a simple supramolecular assembly strategy. The cocrystals exhibit interesting optical properties for its charge transfer (CT) interactions. Meanwhile, a series of three-component (CARB)x (DBZP)1-x (TCNB) crystalline microtubes comprising organic CT interactions have been prepared by the self-assembly with poor solvent co-precipitating method. DFT calculations were used to predict the CT interactions and the binding patterns of donor and acceptor, which suggest that the CT interactions can largely influence the energy level and orbital distributions. Moreover, the SXRD analyses verified the cocrystals are constructed by π-π stacking with a face-to-face model. The solid-state cocrystals and microtubes were well characterized by PXRD, UV absorption spectra, emission spectra, fluorescence lifetime and quantum yield analyses. The obvious red-shift in UV–vis absorption spectra and emission spectra with respect to the free monomer indicate the formation of CT interactions. The emission colors of the mixed microtubes can be tailored from green to orange as well as associated photophysical properties with the increasing of dopant concentrations. Therefore, by the combination of experimental and theoretical studies on the cocrystals and microtubes, this work not only reports the new types of crystalline micro-nano materials, but also provides an in-depth understanding of the relationship between structure and fluorescence effect.

Effective and selective removal of carbazole from model bitumen-derived fuel via adsorption using amine-grafted metal–organic frameworks

The high nitrogen content of bitumen is a major disadvantage because nitrogenous species disturb deep desulfurization and provoke air pollution. Here, denitrogenation of model bitumen-derived fuel (n-octane and toluene mixtures composed of carbazole (CBZ) and dibenzothiophene (DBT)), through selective adsorption of nitrogen-containing compounds (NCCs), was studied firstly using a MOF, MIL-101(Cr) (named M101), especially after functionalization with ethylenediamine (ED) or diethylenetriamine (DETA). The maximum adsorption capacity (Q0) of M101-DETA for CBZ (per unit BET surface area) was 1.4 and 2.1 times that of M101-ED and M101, respectively, confirming the efficiency of the MOF in CBZ adsorption increased with increasing the number of amino groups on the MOF. This tendency was also observed in the model fuel containing both CBZ and DBT. Moreover, M101-DETA interacted more strongly with CBZ than DBT. All the observed results could be explained mainly with hydrogen bonding that was supported by a computational calculation and XPS analysis. Therefore, amine-functionalized MOFs such as M101-DETA (showing a high maximum adsorption capacity of 277.8 mg of CBZ/g) can be suggested as potential/recyclable materials for effective and selective removal of NCCs from fuels with a high concentration of SCCs.

Catalytic activity of metal oxides supported on graphene oxide in oxidative desulfurization and denitrogenation

In this work, the effect of different parameters on catalyst efficiency in the catalytic oxidative desulfurization (ODS) and denitrogenation (ODN) process is studied. A series of samples with different metal compounds, including Ni, Cu, Co, CoNi, CoCu, and CuNi on a reduced graphene oxide (GO) were prepared by an impregnation method. The synthesized samples were carefully characterized by Fourier transform infrared (FTIR), field emission scanning electron microscopy (FESEM), X‐ray photoelectron spectroscopy (XPS), Brunauer–Emmett–Teller (BET) analysis, and X‐ray powder diffraction (XRD) techniques. The potential of this methodology was illustrated by the oxidation of 84.11% carbazole (CBZ) and 88.36% dibenzothiophene (DBT) in model fuel containing 500 ppmw sulfur and nitrogen. The effect of DBT and CBZ initial concentration and oxidant type on the oxidation process was investigated. The initial concentration of 250 ppmw for DBT and 100 ppmw for CBZ showed more efficiency than other initial concentrations (1,000, 750, 500, 250 ppmw) for DBT and (500, 400, 250, 100 ppmw) for CBZ, and NaClO as an oxidant showed higher performance than H2O2, formic acid, and oxygen. The results indicated that the Co‐Cu/rGO catalyst shows higher activity than other prepared catalysts in the oxidation of DBT and CBZ. Moreover, the catalyst could be regenerated three times with no discernible decrease in its catalytic activity. Lastly, the catalytic oxidation of CBZ and DBT was the proposed reaction mechanism.

Interaction of fluorene and its analogs with high-density polyethylene microplastics: An assessment of the adsorption mechanism to establish the effects of heteroatoms in the molecule

The threat of microplastics (MP) pollution in aquatic ecosystems can be even more severe for they are able to interact with organic pollutants that can migrate to adjacent environments. The presence of heteroatoms in organic pollutants can directly influence adsorption onto MP. This research evaluated the adsorption of fluorene (FLN) and its heteroatom analogs dibenzothiophene (DBT), dibenzofuran (DBF) and carbazole (CBZ) onto high-density polyethylene (HDPE) MP from residual (HDPEres) and commercial (HDPEcom) sources. The Langmuir isotherm showed a better fit, while DBT showed higher maximum adsorption capacity (19.2 and 15.8 μmol g−1) followed by FLN (13.4 and 11.7 μmol g−1), and DBF (13.5 and 10.3 μmol g−1) to the HDPEcom and HDPEres, respectively, which indicates a direct correlation with the hydrophobicity of the molecules determined by Log Kow. In contrast, CBZ showed no significant interaction with MP, due to their polar characteristic, thus, no kinetic and thermodynamic parameters could be determined. The adsorption process of all PAH was determined to be exothermic and spontaneous, with low temperatures favoring the process. The pseudo-second-order kinetic models have fitted to the adsorption onto both HDPE; intraparticle diffusion was also observed. Computational studies, physical characterization techniques and batch adsorption experiments demonstrated that the mechanism is governed by hydrophobic interactions, with van der Waals forces as a secondary effect in the adsorption of FLN, DBT and DBF onto HDPEres and HDPEcom. Thus, allowing a deeper understanding of the interactions between HDPE MP and FLN as well with its derivatives.

Oxidative removal of carbazole and alkylated derivatives by FeOx/OMS-2 nanorods activated peroxymonosulfate (PMS) and their utilizing for real wastewater

This study focused on the performance of FeOx/OMS-2 nanorods via PMS activation to degradation carbazole (CBZ) and alkylated CBZs, as well as the possibility of application in oilfield produced water (OPW) with high concentration of co-existing anion/cation. Under the optimized reaction conditions with 0.25 g/L FeOx/OMS-2, 0.5 mM PMS, 30 °C and 150 min, the removal rate and mineralization rate of CBZ at 20 mg/L could be reached 97.5 % (with the reaction rate constant of 0.0344 min−1) and 50.3 %, respectively. The FeOx/OMS-2/PMS system could efficiently degrade CBZ at a wide pH range (pH = 3–9) and showed an excellent anti-interference ability to various anions and cations (Cl−, SO42−, HCO3−, NO3−, Na+, K+, Ca2+, Mg2+, Ba2+ and Sr2+), especially the concentration of NaCl up to 10 g/L. Moreover, it was found that >84.7 % CBZ removal efficiency was reached in real water samples including the actual OPW. The removal rates of various alkylated CBZs were explored and the degradation rate decreased with the increase of methyl number. FeOx/OMS-2 showed an acceptable recyclability and stability, attained a removal efficiency of 63.2 % in the third cycle. Finally, scavenging tests and electron paramagnetic resonance (EPR) showed that 1O2 was the main reactive oxygen species in this system. Accordingly, FeOx/OMS-2/PMS system with high performance was an efficient and promising process for the removal of CBZ in various water treatments.

Toward ultra-high efficiency tandem OLEDs: Benzothiazole-based bipolar hosts and specific device architectures

Tandem organic light-emitting devices (TOLEDs) satisfy the requirements of various applications owing to their high luminance, high efficiency, and long lifetime. A crucial factor in achieving optimal electroluminescence (EL) performance is the host material used for the emitting layer. In this study, a series of benzothiazole (BTZ)-based materials were linked via a phenyl bridge to three different electron-donor moieties, i.e., phenothiazine (PTZ), dimethylacridine (DMAC), and carbazole (CZ), named BTZ-PTZ, BTZ-DMAC, and BTZ-CZ, as bipolar hosts for green phosphors to realize ultra-high efficiency organic light-emitting devices (OLEDs). A Ir(ppy)3-based device based on a BTZ-CZ host is shown to exhibit a satisfactory peak efficiency of 28.0 % (98.8 cd A−1 and 111.6 lm W−1). Additionally, highly efficient green TOLEDs based on a BTZ-CZ host are demonstrated, and they are constructed with a specific charge generation layer and a TiO2 nanoparticle-based internal light extraction structure. The proposed TOLEDs achieved a maximum efficiency of 64.4 % (223.6 cd A−1 and 138.1 lm W−1) and a high maximum luminance of 24.9 × 104 cd m−2, one of the highest levels of efficiency and luminance reported in the literature for Ir(ppy)3-based tandem devices. These results show that the ingenious BTZ-based bipolar hosts exhibit immense potential for the development of tandem OLEDs, thus facilitating the realization of various high-performance EL applications.