Trapping Experiments Research Articles

Reverse engineering of Onivyde® – Irinotecan liposome injection

Onivyde® is an intravenous irinotecan liposomal injection approved by the FDA for the treatment of gemcitabine-refractory metastatic adenocarcinoma of the pancreas in combination with fluorouracil and leucovorin. In the Onivyde® formulation, irinotecan is encapsulated in the inner compartment of the liposome using sucrose octasulfate as a trapping agent, and stabilized by a pegylated lipid membrane, resulting in prolonged circulation in the body. Due to its complex formulation design, there is limited information available regarding the critical quality attributes (CQAs) of Onivyde® and suitable methods for evaluating these attributes. In this study, we have developed a series of analytical methods to comprehensively characterize Onivyde®. These methods encompass particle size analysis, morphology and structure assessment, examination of physical and chemical properties, determination of drug and lipid contents, and evaluation of its release behavior in vitro.

Rational design of CuNd1.9Dy0.1O4 anchored on carbon nanotubes as an efficient sonophotocatalyst for pollutant degradation

In the pursuit of novel catalytic materials, CuNd(2-x)DyxO4/CNT nanocomposites were synthesized by a facile microwave-assisted sol-gel synthesis. The crystal structure, morphology, elemental composition and optical properties of the prepared CuNd(2-x)DyxO4/CNT nanocomposites were systematically analyzed and their catalytic efficiency was assessed through the sonophotocatalytic degradation of cefixime. Dysprosium doping and the incorporation of CNT synergistically enhanced the sonophotocatalytic activity by improving visible light absorption and charge separation. Under optimal conditions of 20 mg catalyst, 15 mg/L cefixime and pH 7, CuNd1.9Dy0.1O4/CNT exhibited the highest sonophotocatalytic degradation efficiency of 90.5 % in 120 min, with exceptional stability over four cycles. The trapping experiments and electrochemical studies contributed to a deeper understanding of the degradation mechanism. The toxicity evaluation by Brine shrimp lethality assay showed the weak toxicity of the resulting solution. The current study paves new insights into the use of neodymium-based perovskite-like materials for the potential application in environmental remediation.

One-step construction of Sn-doped Bi2MoO6 nanosheets for enhanced photocatalytic organic pollutants degradation and Cr(VI) reduction

Photocatalytic technology is widely used to remove environmental pollutants, and the development of high-performance photocatalysts is an important prerequisite for boosting photocatalytic processes. Herein, Sn-doped Bi2MoO6 nanosheets were constructed by one-step solvothermal method. The experimental results indicate that the Sn doping not only tunes the band structure of Bi2MoO6, but also effectively promotes the photogenerated charge separation, thus providing abundant free charge for photocatalytic reactions. The optimized Sn-Bi2MoO6-2 sample shows the degradation efficiency of TC and MBT reaching 81% (for 3hours) and 85% (for 2hours), respectively, and the removal efficiency of Cr(VI) is 1.5 times compared with that of pristine Bi2MoO6. Moreover, the experiments with different pH, inorganic cations and anions were carried out to investigate the practical application potential of the photocatalyst, and the Sn-Bi2MoO6-2 also exhibits excellent photocatalytic performance for decomposing antibiotic contaminants in river water. Furthermore, mass spectra and radical trapping experiments explored the possible photocatalytic degradation processes. This work explored the multiple positive roles of Sn-Bi2MoO6 materials in the photocatalytic system, which provides a promising strategy for constructing efficient photocatalysts for environmental remediation.

Asymmetric semiochemical-mediated interactions of Monochamus spp. (Coleoptera: Cerambycidae) and associated bark beetles in Portugal and Canada.

Some coniferophagous bark and woodboring beetles overlap spatially and temporally in host trees. These larval interactions have been classified as competitive and predatory in favor of the larger and more mobile woodborer larvae. In some bark beetles, larval traits have been reported that facilitate evasion of woodborer larvae. Both bark beetles and woodborers mediate mating on host material with volatile pheromones. Although it is known that some woodborers eavesdrop on bark beetle aggregation pheromones to facilitate host location, it is not known what effect woodborer pheromones have on bark beetles. The pheromone monochamol is used by most Monochamus spp. Dejean and coniferophagous species from this genus co-occur with bark beetles in host tissues. Because of the negative consequences these larval interactions have for bark beetles, we hypothesized that the woodborer pheromone monochamol would inhibit captures of sympatric and synchronic bark beetles to intercept traps baited with their aggregation pheromones and host volatiles. We tested this hypothesis in 2 systems, 1 in Ontario, Canada, and another in Setúbal, Portugal with field trapping experiments. Trap captures of Ips sexdentatus (Boerner) (Coleoptera: Scolytinae), Orthotomicus erosus (Wollaston) (Coleoptera: Scolytinae) (2 bark beetle species captured in Portugal), and Ips pini (Say) (Coleoptera: Scolytinae) (1 bark beetle species captured in Canada) were reduced by the presence of monochamol. These results suggest that an additional evasion mechanism in some bark beetles is the detection of the woodborer pheromone monochamol and subsequent reduced response to aggregation pheromone and host volatiles in the presence of this woodborer pheromone.

Formation of Radical-like NH Ligand from NH3 at Ambient Conditions Mediated by Dialkyl Rare-Earth Complexes.

Although intensive work on ammonia activation has been carried out in recent decades, generating nitrogen-centered radicals from NH3 under ambient conditions remains quite challenging. In the presented research, the conversion of NH3 to radical-like NH ligand has been achieved by the reactions of a series of dialkyl rare-earth (RE) complexes (1-RE, RE = Tb, Dy, Y, Ho, Er, Yb, and Lu) supported by β-diketiminate ligands with NH3 in n-hexane at room temperature, resulting in the formations of the radical-like μ3-NH ligands containing trinuclear RE complexes (2-RE). The radical-like feature of the μ3-NH ligand was revealed by electron paramagnetic resonance and magnetic measurements, radical trapping experiments, and computational spin density analysis. In addition, H2 was detected to form during the reaction of 1-RE with NH3, indicating that the radical-like μ3-NH ligand was likely to be generated via N-H bond homolysis. Moreover, the solvents and coordination pattern of β-diketiminate ligands are crucial for the formation of the radical-like μ3-NH ligand from NH3. When toluene instead of n-hexane was used in the reaction of 1-RE with NH3, an array of octaamido tetranuclear RE complexes (3-RE) was obtained. The reaction of the dialkyl yttrium complex (4-Y) bearing a modified β-diketiminate ligand, in which the two mesityl substituents are replaced by a 2,6-diisopropylphenyl group and a 2-(dimethylamino)ethyl group, with NH3 in both n-hexane and toluene only yielded a tetranuclear yttrium complex carrying the dianionic closed-shell μ3-NH ligands (5-Y).

Novel 3D plate-like g-C3N4/BiOCl heterojunction as a highly efficient photocatalyst for the degradation of carbofuran in wastewater under visible light irradiation

The g-C3N4/BiOCl (gCN-BCl) heterojunction photocatalyst was synthesized using a low-temperature precipitation method for effective photocatalytic degradation of carbofuran (CBF). All gCN-BCl composites demonstrate greater efficacy in removing CBF compared to its individual constituents. The synergistic effect of incorporating the 0D structured BiOCl onto the 2D structured g-C3N4 was comprehensively examined using various microscopic, X-ray, and spectroscopic analytical techniques. Additionally, optical and photoelectrochemical analyses were conducted. The findings validated that the interaction between the two semiconductors at the heterointerfaces enhanced remarkable physical and structural stability, promoted high charge separation and transfer properties, and improved photocatalytic degradation. Under optimal conditions, 5-gCN-BCl (0.25 g/L) achieved a CBF (5 mg/L) removal efficiency of 95.7 % under visible light irradiation of 120 min, achieving 3.1- and 5.9-times higher degradation rate than the pure BiOCl and g-C3N4, respectively. The radical trapping experiments indicated that the h+ and •O2− were the primary reactive species involved in the CBF degradation. Furthermore, the potential toxicity of CBF and its intermediates was assessed, revealing that the photocatalytic degradation process significantly lowered the ecotoxicity of pesticide wastewater. The potency of 5-gCN-BCl was also evaluated in tap water and real wastewater samples, with CBF degradation efficiencies of 85.8 %, 47.6 %, and 38.7 % in tap water, municipal, and pesticide industry wastewater, respectively. Additionally, artificial neural network (ANN) modeling was employed to predict and optimize the photocatalytic degradation process, providing further insights into the system’s performance. The outcomes of this work offer valuable insights into the development of heterojunction photocatalysts with superior stability and efficacy for eliminating pesticides from water bodies.

RAD18-catalysed formation of ubiquitination intermediate mimic of proliferating cell nuclear antigen PCNA

The 2-((2-chloroethyl)amino)ethane-1-thiol (CAET)-based chemical trapping strategy is a practical tool for mechanistic studies of E3-catalysed ubiquitination. However, the construction of ubiquitination intermediate mimics (E2-Ub-substrate conjugates) via CAET has been limited to peptides, while its application to folded protein substrates remains unexplored. Here, we report that disulfide bond formation between E2-Ub (RAD6A-Ub) and the folded protein substrate PCNA (proliferating cell nuclear antigen) occurs upon the addition of the PCNA-associated E3 ligase RAD18. Leveraging this finding, we employed intein splicing technology to generate a stable, covalently linked RAD18-RAD6A-Ub-PCNA complex, enabling chemical crosslinking mass spectrometry (CX–MS) analysis to study the structure of this complex. This work showcases use of a substrate-associated E3 ligase to promote disulfide bond formation between an E2-Ub conjugate and a folded substrate for CAET-based trapping, thereby expanding the scope of this technique.

Engineering Ag-Modified BiOCl as an Efficient and Effective Catalyst for Solar Light-Driven Organic Pollutant Degradation and Hydrogen Production.

The direct conversion of solar energy into clean fuels has emerged as an effective approach for future energy production and addressing environmental challenges. This research focuses on the synthesis of BiOCl using a straightforward hydrothermal method with Ag modification achieved through green synthesis. These materials were applied to enhance photocatalytic processes and hydrogen (H2) evolution. Comprehensive characterization of the synthesized photocatalysts was performed by using techniques, such as XRD, SEM, BET, XPS, and UV-vis spectroscopy. The Ag/BiOCl composite demonstrated impressive photocatalytic performance, achieving degradation rates of 96% for RhB, 87.7% for TC, and 85% for HQ under 18 min of solar irradiation. Additionally, a high mineralization rate of 92% was observed through Total Organic Carbon (TOC) analysis. Furthermore, the Ag/BiOCl composite exhibited a significant H2 evolution rate of 565 μmol g-1 h-1, which is nearly double that of pure BiOCl. The interaction between Ag and BiOCl was found to enhance the generation of O2- radicals, as confirmed by radical trapping experiments, with the underlying mechanism elucidated using LC-HRMS. The nanoparticles also demonstrated excellent degradation of industrial waste, highlighting the potential of Ag/BiOCl for use in the purification and sterilization of industrial effluents.

Construction of magnetically separable S-scheme BiFeO3/Cl-g-C3N4 heterostructure photocatalyst for simultaneous removal of Cr(Ⅵ) and tetracycline in aqueous solution: Performance and mechanism insight

A green, efficient and recyclable magnetic BiFeO3/Cl-g-C3N4 photocatalyst was prepared for the simultaneous removal of Cr(Ⅵ) and tetracycline (TC) from water by wet chemical and thermal synthesis methods. Experimental results revealed that BiFeO3/Cl-g-C3N4 achieved a removal efficiency of 96.1 % for Cr(Ⅵ) and 98.2 % for TC under visible light irradiation for 50 min at pH 6. The results of the work function, charge density difference, UV–vis DRS, PL, PC and EIS tests indicate the formation of S-scheme heterojunctions between BiFeO3 and Cl-g-C3N4, which exhibits superior carrier separation and migration efficiency. The evidence for interfacial charge transfer from BiFeO3 to Cl-g-C3N4 within BiFeO3/Cl-g-C3N4 was further corroborated by means of ISIXPS, EPR and KPFM. Moreover, calculations of the density of states demonstrate that the introduction of Cl enhances the reduction capability of BiFeO3/Cl-g-C3N4. Results from ESR tests and trapping experiments has demonstrated that the singlet oxygen (1O2) and electrons are the primary active species. Furthermore, the high removal rates of TC and Cr(VI) from industrial wastewater and groundwater, coupled with the lower ecotoxicity of TC degradation intermediates, indicate that BiFeO3/Cl-g-C3N4 has the potential for practical applications. After five cycles, the BiFeO3/Cl-g-C3N4 still removed 90.5 % of TC and 96 % of Cr(Ⅵ).

Experimentelle Beobachtung eines terminalen Borylen‐Distickstoff‐Addukts durch Spaltung eines 1,2,3,4,5‐Diboratriazolins

AbstractWährend Azide mit einfachen Alkenen nur unter harschen Bedingungen reagieren, reagiert ein Diboranalogon eines Alkens, das zweifach durch cyclische Alkyl(amino)carbene (CAAC) stabilisierte Dicyanodiboren 1, spontan mit organischen Aziden (7–10 Äq.) bei Raumtemperatur, um zwei Äquivalente stabiler CAAC‐stabilisierter Imino(cyano)borane (2‐R) zu ergeben. NMR‐spektroskopische Kontrollen der Reaktionsmischungen zeigen die anfängliche Bildung einer 1 : 1‐Mischung aus 2‐R und einem relativ langlebigen Zwischenprodukt (Int), welches in Gegenwart von überschüssigem Azid in ein zweites Äquivalent 2‐R umgewandelt wird. In Abwesenheit von überschüssigem Azid zersetzt sich Int jedoch zu 3, dem Produkt einer intramolekularen C−H‐Bindungsaktivierung durch eine mutmaßlich zweifach koordinierte Borylen‐Zwischenstufe, „(CAAC)B(CN)“. Mechanistische Erkenntnisse aus Abfangexperimenten, NMR‐spektroskopischen und hochauflösenden Massenspektrometrie‐Daten sowie DFT‐Berechnungen zeigen, dass Int das endständige Borylen‐Stickstoff‐Addukt [(CAAC)B(CN)(η1‐N2)] ist. Die Bildung der Iminoborane 2‐R aus Diboren 1 und RN3 erfolgt über eine Azid‐Diboren‐Huisgen‐[3+2]‐Cycloaddition, gefolgt von einer [3+2]‐Cycloreversion, wobei 2‐R und [(CAAC)B(CN)(η1‐N2)] entstehen. Letzteres durchläuft dann entweder eine N2‐Abspaltung und intramolekulare C−H‐Bindungsaktivierung zur Bildung von 3 oder eine Staudinger‐artige Reaktion mit einem zweiten Äquivalent Azid zur Bildung eines zweiten Äquivalents des Iminoborans 2‐R.

Response of hibiscus mealybug (Hemiptera: Pseudococcidae) to citrus volatiles induced by mechanical injury.

Hibiscus mealybug, Nipaecoccus viridis (Newstead) (Hemiptera: Pseudococcidae), is a recent invasive pest of citrus and many other crops in Florida. Nipaecoccus viridis attacks all above ground parts of citrus trees and heavy infestation can cause leaf drop and premature abortion of developing fruits. We quantified greater captures of N. viridis in cardboard band traps on areas of citrus trees that were intentionally injured by mechanical rasping of epidermal tissues as compared with similar but uninjured citrus branches. Direct field collection of headspace volatiles from mechanically injured or intact citrus branches revealed both qualitative and quantitative differences. Certain volatiles (γ-terpinene, citronellal, citronellyl acetate, β-E-farnesene, α-humulene, and α-E-E-farnesene) were only present in samples from damaged citrus branches. Behavioral assays using a laboratory Y-tube olfactometer revealed attraction of N. viridis to volatiles associated with mechanical damage of citrus including synthetic β-ocimene, γ-terpinene, sabinene, isomers of farnesene, and citronellal when loaded into lures at either of 2 concentrations (0.01 or 0.1 µg/µl). Subsequent field trapping experiments confirmed increased captures of various life stages of N. viridis in cardboard band traps baited with a 10.0 µg/µl concentration of farnesene:ocimene:sabinene blend (in 7:13:17 ratio), as well as those releasing either farnesene or ocimene alone at this same concentration, as compared with the mineral oil (diluent) negative control. Our results indicate that common plant related terpenes released by citrus following mechanical damage may be useful for development of an effective monitoring trap for N. viridis.

Experimental Observation of a Terminal Borylene-Dinitrogen Adduct via Cleavage of a 1,2,3,4,5-Diboratriazoline.

While azides do not react with simple alkenes except under harsh conditions, a diboron alkene analogue, the doubly cyclic alkyl(amino)carbene (CAAC)-stabilized dicyanodiborene 1, reacts spontaneously with organic azides (7-10 equiv.) at room temperature to yield two equivalents of stable CAAC-imino(cyano)boranes (2-R). NMR-spectroscopic monitoring of the reaction mixtures shows the initial formation of a 1 : 1 mixture of 2-R and a relatively long-lived intermediate (Int), which in the presence of excess azide is converted into a second equivalent of 2-R. In the absence of excess azide, however, Int decomposes to 3, the product of an intramolecular C-H activation by a putative dicoordinate borylene intermediate "(CAAC)B(CN)". Mechanistic insights from trapping experiments, NMR-spectroscopic and high-resolution mass spectrometry data, as well as DFT computations reveal that Int is the terminal borylene end-on-dinitrogen adduct [(CAAC)B(CN)(η1-N2)]. The formation of the iminoboranes 2-R from diborene 1 and RN3 proceeds via an azide-diborene Huisgen-type [3+2] cycloaddition reaction, followed by a retro-[3+2] cycloaddition, yielding 2-R and [(CAAC)B(CN)(η1-N2)]. The latter then undergoes either N2 extrusion and intramolecular C-H activation to generate 3, or a Staudinger-type reaction with a second equivalent of azide to generate a second equivalent of the iminoborane 2-R.

Fabrication of mesoporous Sm-Nd2O3/Thymine doped gC3N4 nanocomposite for the adsorption and photodegradation of ciprofloxacin under visible light

The ciprofloxacin (CIP) antibiotic was degraded using Sm-Nd2O3 decorated Thymine doped gC3N4 (Sm-Nd2O3/T-gC3N4) nanocomposite under visible light irradiation. The oxygen-containing component like thymine doped in the gC3N4 significantly improves the active sites of the catalyst and its ability to absorb light, which highly influences the adsorption and photocatalytic activity. The chemical and morphological analysis of the nanocomposite were studied utilizing the XRD, FTIR, HRSEM, HRTEM, EDAX, UV-DRS, XPS, BET, and PL. The photocatalytic activity was investigated under several factors such as pH, initial concentration of CIP, catalyst dosage, inorganic anions, and real lake water sample, to optimize and enhance the photocatalytic efficiency of Sm-Nd2O3/T-gC3N4 nanocomposite, as a result, the degradation efficiency achieved to 99.65 % within 120 min with the rate constant of 0.0472 min−1. The Z-scheme mechanism of the Sm-Nd2O3/T-gC3N4 photocatalyst was proposed based on the Mott-Schottky and trapping experiments. Further, the degradation pathway of CIP was postulated based on the intermediates, identified by the LC-MS analysis.

Efficient photocatalytic degradation of tetracycline and its derivatives by green recyclable PAN/Bi2WO6/Cu2O nanofiber membrane

The use of tetracycline antibiotics in industry, healthcare, animal husbandry, agriculture, and aquaculture has resulted in excessive concentrations in a variety of aquatic environments. In this work, PAN/Bi2WO6/Cu2O nanofibrous membranes (PBC ENMs) with photocatalytic degradation performance were successfully prepared using electrostatic spinning technique, and the morphology of catalysts and PBC ENMs were characterised by SEM, BET and UV–Vis. The results demonstrated that the prepared nanofibrous membranes could achieve 97.05 % photocatalytic degradation of TC under visible light, and the degradation efficiencies of its derivatives, chlortetracycline (CTC) and oxytetracycline (OTC), reached 90.87 % and 85.12 %, respectively. Free radical trapping experiments and mechanistic analyses showed that·O2– is the main active factor in the degradation process. The highest degradation rate of 97.05 % was achieved at initial pH = 7.2.PBC ENMs adsorbed above 87.5 % after six cycles of the experiment. The highest degradation rate of 97.05 % was achieved at initial pH = 7.2 PBC ENMs adsorbed above 87.5 % after six cycles of the experiment. Based on the above advantages, the preparation process of PBC ENMs is simple, low-cost and has good catalytic effect, which provides a simple and efficient treatment means for the treatment of TC wastewater and has a broad application prospect.

On the trapped magnetic moment in type-II superconductors

Abstract Measurements of the trapped (remanent) magnetic moment, M trap ( H ) , when a small magnetic field H is turned off after cooling below the superconducting transition temperature, Tc , or ramping a magnetic field up and down after cooling in a zero magnetic field, offer substantial advantages in difficult cases of small samples and large field-dependent backgrounds, which is relevant for hydrogen-based ultra-high-T c superconductors (UHTS). Until recently, there was no need for a separate paper on the trapped magnetic flux for well-known critical-state models due to the simplicity of the physics involved. However, recent publications showed the need for such an analysis. This note summarizes the expectations for the Bean model with constant critical current density and the Kim model with field-dependent critical currents. It is shown that if the trapped moment is fitted to the power law, M trap ∝ H α , the fixed exponent α = 2 is exact for the Bean model, while Kim models show a wide interval of possible values, 2 ⩽ α ⩽ 4 . Furthermore, accounting for reversible magnetization expands the range of possible exponents to 1 ⩽ α ⩽ 4 . In addition, demagnetizing factors are essential and make the trapped moment orientation dependent even in isotropic materials. As a concrete application, it is shown that flux trapping experiments performed on H3S UHTS compounds can be well described using this generalized approach, lending further support to the type-II superconducting nature of H3S under ultra-high pressure.

Synthesis of tin selenide nanoparticles using Polygonum avicular extract decorated on graphitic carbon nitride for enhancing photodegradation of amoxicillin trihydrate and photoproduction of hydrogen peroxide

In this research, tin selenide nanoparticles (SnSe-NPs) were synthesized using Polygonum avicular extract via the hydrothermal method and decorated on graphitic carbon nitride (g-C3N4) by the simple sonicated method to produce SnSe/g-C3N4 composites. The characterization and properties of the SnSe/g-C3N4 composites, as compared to pristine SnSe and g-C3N4, were determined by Fourier-transform infrared spectroscopy, X-ray powder diffraction, scanning electron microscope, transmission electron microscopy, field emission scanning electron microscopy, X-ray photoelectron spectroscopy, ultraviolet–visible diffuse reflectance spectroscopy, Mott-Schottky, and electrochemical impedance spectroscopy. As a result, the SnSe-NPs possessed the rod-like shape and after the decoration onto the g-C3N4 sheet surface, it reduced the bandgap energy of the g-C3N4 from 2.58 downward 1.43 eV. Besides, the photoactivities of the 10-SnSe/g-C3N4 catalyst were investigated via both sides of amoxicillin trihydrate (AMXT) photodegradation and hydrogen peroxide (H2O2) photoproduction, in which the results were achieved 87.84 % AMXT and 85.48 μM H2O2, respectively, under visible light. Furthermore, the photodegradation was consistent with the pseudo-first-order kinetics and it performed the highest photodegradation at pH ∼5, while the importance of isopropyl alcohol as a trapping agent and •O2− radicals was affirmed in the H2O2 photoproduction. Moreover, the photoproduction of H2O2 was remained after 4 cycles achieved at 62.70 % in the final cycle, which demonstrated the stability and reusability of the 10-SnSe/g-C3N4. These aforementioned results demonstrate that the SnSe/g-C3N4 material is a promising candidate for addressing environmental pollution and energy scarcity issues.

Open frame-like Co-Fe oxides superstructures for highly efficient cross-dehydrogenative coupling reaction of N-phenyltetrahydroisoquinoline under mild conditions

An open frame-like Co-Fe oxides catalyst has been successfully prepared using a time-controlled strategy. Benefiting from the unique open frame-like superstructure and synergistic bimetallic composition, this novel catalyst exhibits excellent catalytic activity (up to 91 % isolated yield) and substrate suitability for Cross-Dehydrogenative Coupling reaction (CDC) of N-phenyltetrahydroisoquinolines and nitroalkanes using oxygen as the oxidant under mild reaction conditions. And after several runs, the reused catalyst still maintains great stability. This may attributed to the interaction between Fe and Co. In addition, through the radical trapping experiments, we found that O2·− species play an important role in the cross-dehydrogenative coupling reaction.

Rape straw biochar-assisted preparation of flower-like BiOCl with enriched oxygen vacancies for efficient photocatalytic CO2 reduction and pollutants degradation

Utilizing photocatalytic technology to transform CO2 into high added value chemical products has represented an effective strategy for alleviating the climate problems that have arisen due to excessive CO2 emissions. As a typical bismuth-based photocatalyst, BiOCl has garnered widespread attention due to its unique layered structure and low toxicity. However, the low light utilization efficiency and the rapid recombination of e−/h+ pairs severely hinder the practical application of BiOCl. Introducing oxygen vacancies (OVs) into BiOCl has been demonstrated to be one of the effective strategies for enhancing the photocatalytic performance of BiOCl. However, introduction of OVs through a mild and cost-effective approach remains a significant challenge. In this work, we developed a strategy for introducing OVs on BiOCl, which indues the growth of BiOCl into flower-like spherical structures and introduction of abundant OVs through addition of rape straw biochar (RC) under hydrothermal conditions. The synergistic interaction of RC and OVs endows with BiOCl more active sites as well as higher photogenerated carriers (e−/h+) separation efficiency. When the mass ratio of RC to BiOCl is 0.5 % (RC-0.5), the sample demonstrates the best performance, conversion of CO2 to CO on the sample is 4.0 μmol g−1 h−1, which is 3.08 times higher than that on the reference BiOCl. Additionally, versatility of the photocatalysts was further evaluated through photocatalytic degradation of rhodamine B (RhB) and perfluorooctanoic acid (PFOA). The degradation rate constant of RhB and PFOA on the RC-0.5 sample is 0.0642 min−1 and 0.00566 min−1, respectively, which is 2.26 times and 0.43 times higher than that on the reference BiOCl. Total organic carbon (TOC) experiments demonstrate that RhB can be effectively mineralized into CO2, H2O and small molecules on the photocatalyst. The main reactive species involved in the photocatalytic degradation process were investigated through active free radical trapping experiments and electron paramagnetic resonance (EPR). This work provides a viable strategy for the development of high-performance BiOCl photocatalysts for environmental applications.

BiOBr/SnO2/ZnO Catalyst With Interfacial Effect Enhanced Photocatalytic Degradation of Organic Dye

ABSTRACTBiOBr nanosheets were loaded onto SnO2 quantum dots, ZnO nanosheets, and SnO2/ZnO‐2 (SZ‐2) to form different heterojunction photocatalysts by sonochemistry, respectively. The photocatalytic activity of the prepared photocatalysts was evaluated by degrading the target dye Rhodamine B (RhB). The results showed that the degradation efficiency of BiOBr/SnO2/ZnO (BSZ) for RhB reached 97.5% at 80 min. The significant increase in catalytic activity of BSZ was attributed to the synergistic and interfacial effects among the three materials. Combined with the radical trapping experiments, it can be concluded that the catalytic mechanism of BSZ as a dual Z‐type heterojunction.

Specific ion effects on the self-assembly and interfacial properties of double- and single-chain cationic amphiphiles

Understanding the specific ion effects (SIE) on the self-assembly of ionic amphiphiles is a key unresolved issue in colloid and interface chemistry. We investigated the SIE on interfacial properties, aggregation behaviours, and interfacial molarities of dioctyldimethylammonium (DiC8X) and tetradecyltrimethylammonium (TTAX) (X = Br, Cl, and Ac) surfactants. Our results demonstrate strong SIE on the aggregation behaviours in both single-chain and double-chain surfactants. The aggregation behaviour depends on the net effect of nonspecific interactions and SIE. Vesicle-micelle transitions are observed exclusively in the double-chained surfactants studied in this work, regardless of their tail symmetry, and are absent in the single-chained surfactants examined. These transitions are counterion-dependent, occurring only with bromide, while the surfactants bearing acetate consistently form vesicles. The chemical trapping (CT) results reveal several key insights on interfacial molarities: 1) double-chain surfactants exhibit higher interfacial water molarity compared to single-chain surfactants, with counterion molarity showing an inverse trend; 2) within both TTAX and DiC8X classes, the interfacial water molarity is highest for surfactants with bromide, followed by chloride, and lowest for acetate; 3) for surfactants undergoing vesicle-micelle transitions, both interfacial water and bromide molarity increase with rising surfactant concentration at low concentration ranges, indicating looser interfacial packing with increasing concentration; and 4) the combined CT and molecular dynamic simulations indicate that acetate penetration into interfacial regions significantly increases with surfactant concentration in TTAAc and DiC8Ac aggregates, explaining the consistent vesicle formation of amphiphiles with acetate. Overall, this study provides critical insights into the delicate balance-of-forces controlling the morphologies of aggregates composed of ionic amphiphiles.