Trapping Experiments Research Articles

Tannin-based non-isocyanate polyurethane wood adhesive rich in complicated cross-linked networks with ultra-strong bonding property and excellent water resistance by introducing poly-urea structure

Developing of bio-based wood adhesives is an inevitable common topic in the development at top speed of wood industry. Herein, a bio-based tannin wood adhesive, named as tannin-based non-isocyanate polyurethane-urea (TNIPU-U), was designed which showing a ultra-strong adhesion and water resistance performance by two-step approach. A plausible mechanism was proposed, which implied that urea acted as the crosslinker to connect with derived intermediates containing free amino groups rooted from the reaction of tannin, dimethyl carbonate (DMC), and HMDA, to introduce urea linkages in traditional TNIPU. Furthermore, addition of urea to act as a trapping agent to capture excessive free HMDA in TNIPU adhesive, promoting additional polyurea formation, leading to avoidance of its emission during the hot-pressing process. This will convert the imperfection of TNIPU to a superiority by a eco-friendly strategy. The complicated cross-linked networks will be obtained that are rich in physical entanglement, covalent bonds, and hydrogen bonds. Compared with the TNIPU, the shear strength of TNIPU-U adhesive, after soaked in hot water and boiling water for 3 h, exhibited increase by 17.88 % and 34 %, respectively, indicating the potential for use under harsher conditions. Moreover, the TNIPU-U adhesive exhibits an excellent bonding performance (1.93 MPa) that greatly exceeds the China National Standard (GB/T 9846–2015, ≥ 0.7 MPa) requirement for exterior-grade plywood type I. It is comparable to commercial phenol-formaldehyde resin on the aspect of water tolerance. It can be applied to particleboard preparation and bamboo bonding as well, showing a well-adopted feature. This study provides an efficient, low-cost, and sustainable strategy for high performance bio-based wood adhesives.

In situ construction of CuBi2O4/Bi4O5Br2 Z-scheme heterojunction with enhanced photocatalytic degradation performance for polyphenolic contaminant in wastewater

Photocatalytic technique is one of the clean and promising routes for wastewater purification. In this work, a different CuBi2O4/Bi4O5Br2 Z-scheme heterojunction were successfully prepared via an in-situ mechanical agitation method. The 10% CuBi2O4/Bi4O5Br2 (10% CBO/BOB) heterojunction showed the highest photocatalytic degradation activity for catechin, and ∼99.8% catechin was degrade within 40 min visible light stimulation, which is (0.0757/min) about 6.2-folds and 8.8-folds to that of Bi4O5Br2 (0.0122/min) and CuBi2O4 (0.0086/min), The pH=7 is the optimal reaction condition for catechin degradation. Besides, The photocatalytic degradation capacity of the 10% CBO/BOB heterojunction displayed the positive and negative relationship to the dosage of catalyst and initial concentration of catechin, respectively. The enhanced photocatalytic activity of CuBi2O4/Bi4O5Br2 Z-scheme heterojunction can be ascribed to the improvement of the charge separation and light utilization rate. The results of ESR and trapping experiments revealed that the ·O2-, h+ and ·OH are the primariy reactive substances for catechin degradation. Additionally, the transfer pathway of the photogenerated charges in the CuBi2O4/Bi4O5Br2 Z-scheme heterojunction as revealed by the ESR, Mott-Schottky curve and UV-Vis diffuse reflectance absorption spectroscopy. This work provide a new idea for designing and preparing the novel Bi4O5Br2-based photocatalyst for TCM wastewater purification.

Constructing robust Z-type BiOBr/Br-doped g-C3N4 heterojunctions for visible light-assisted photocatalytic decontamination of norfloxacin

In order to remediate the environment in a green way, the development of new and effective photocatalytic heterojunctions has received great attention from researchers in recent years. Herein, we assembled BiOBr-decorated Br-doped g-C3N4 (BiOBr/BrCN) hybrid heterojunctions in different percentages (BiOBr content = 5–30 wt%) to achieve effective photocatalytic heterojunctions for visible-light-prompted degradation of antibiotic norfloxacin (NOR), in which reducing the photocarriers recombination rate. Obviously, BiOBr/BrCN composites endorsed greater photodecomposition performance of NOR under visible-light illumination. The 10 wt%BiOBr/BrCN photocatalyst decomposed 95.5 % of NOR in 1.5 h, which are approximately 2.5 and 1.7 times of enhancement compared with BrCN and BiOBr, respectively. The enlarged response to visible-light and the efficient separation of photo-induced carriers in the developed Z-system heterojunction between BiOBr and BrCN were behind the boosted photocatalytic activity. Besides, the trapping experiments demonstrated that both •O2− and h+ species take significant roles in the degradation of NOR antibiotic, which supports the proposed mechanism. In addition, the degradation efficiency displays an insignificant decrease after the fifth cycle, indicating that the synthesized BiOBr/BrCN photocatalyst system has a great stability for the practical applications.

Facile electrospinning-electrospray method to fabricate flexible rice straw-derived cellulose acetate/TiO2 nanofibrous membrane with excellent photocatalytic performance

A novel and facile electrospinning-electrospray (EE) method that based on electrospinning technique and simultaneous electrospray was proposed to anchor TiO2 (P25) nanoparticles on the surface of rice straw-derived cellulose acetate (CA) nanofiber, a series of EE-CA/P25 nanofibrous membranes with different P25 dosage were successfully fabricated, which were characterized in terms of SEM, TEM, FI-IR, XRD, DRS, PL, UV–vis and 3D-EMMs, etc. Results confirmed that P25 nanoparticles were anchored on the surface of CA nanofiber. For different organic dyes of Methylene blue (MB), Rhodamine B (RhB) and Methyl orange (MO), EE-CA/P25(0.05) nanofibrous membrane toward MB dye showed the best photocatalytic degradation efficiency of 99.13 % after 30 min of light exposure. For the different antibiotics of Tetracycline (TC), Ciprofloxacin (CIP) and Sulfamethoxazole (SMX), EE-CA/P25(0.05) exhibited the best photocatalytic degradation efficiency of 83.59 % for TC after 30 min of light exposure. Moreover, EE-CA/P25(0.05) exhibited a good antimicrobial efficiency of 98.42 % for E. coli, and maintained 97.49 % after 5 cycles. The reactive radical trapping experiments revealed that h+, •O2−, and •OH participated in the reaction, and h+ and •O2− played a major role in the photocatalytic degradation process. Moreover, EE-CA/P25(0.05) flexible membrane was easy to recycle and transform rice straw waste into treasure.

Fabrication of Co(II)-based coordination polymer for photocatalytic degradation: Selective removal of cationic methyl violet dye

In this study, a new coordination polymer (CP) was designed and synthesized to evaluate the photocatalytic properties for water remediation. The Co(II)-based CP {[Co(HL)(bid)(H2O)]·2H2O}n (1) was hydrothermally synthesized using the ligand 5-(4′-carboxyphenoxy)isophthalic acid (H3L) and 1,4-bis(1-imidazolyl)-2,5-dimethylbenzene (bid). The coordination polymer (1) has been characterized by various spectral techniques, thermogravimetric (TGA), and single crystal X-ray technique. X-ray data revealed that (1) exhibits 2D framework having an octahedral coordination geometry around the Co(II) ions, having μ1:η1-η1 mode with chromophore CoO4N. FT-IR analysis confirmed the asymmetric monodentate binding modes of the carboxylate ligand. The CP 1 has demonstrated optical semiconducting properties, rendering them promising candidates for photocatalytic applications. The catalyst (1) has been effectively utilized in the breakdown of several organic dyes, such as methylene blue (MB), methyl orange (MO), methyl violet (MV), and rhodamine B (RhB). The results showed that at pH 4, with a dosage of 30 mg of catalyst (1), 92.08 % of MV was degraded at a concentration of 20 ppm. Additionally, the mechanistic pathway for light-driven MV decomposition was investigated through experimental approaches, specifically radical trapping experiments.

Fabrication of α-Fe2O3/TiO2 heterojunction for photocatalytic degradation of doxycycline hydrochloride

In this work, flower-like TiO2 (TiO2-F) was first prepared by modulating the morphology of TiO2, and then, α-Fe2O3 was loaded onto TiO2-F to successfully prepare α-Fe2O3/TiO2-F heterojunction materials. The material showed excellent degradation properties of doxycycline hydrochloride under visible light. The photocatalytic degradation efficiency of α-Fe2O3/TiO2-F2 for doxycycline hydrochloride under visible light reached 95.76 % in 120 min, and its pseudo-first-order degradation rate constant was 0.02647 min−1, which was 3.68 and 2.01 times higher than those of α-Fe2O3 and TiO2 alone, respectively. This good photocatalytic performance is attributed mainly to the introduction of α-Fe2O3 to form a Type II heterojunction with floral TiO2 (TiO2-F), which is capable of promoting the separation of electron–hole pairs of photocatalysts and exhibiting a stronger redox capacity. The material exhibits notable stability and maintains high degradation efficiency even after undergoing multiple cycles. Furthermore, free radical trapping experiments and electron spin resonance (ESR) characterization revealed that hydroxyl radicals play a dominant role in this system. Finally, the degradation pathways were analyzed, and relevant toxicological analyses were performed, indicating that the toxicity of doxycycline hydrochloride gradually decreased during the photocatalytic degradation process.

Enhanced photocatalytic performance of SnS2/ZnO Z-scheme composite photocatalysts for efficient environmental remediation

Photocatalysts based on zinc oxide (ZnO) are promising for environmental applications, but their weak photoresponse and low photocarrier separation efficiency limit their practical use. To tackle this issue, we constructed Z-scheme composite photocatalysts of ZnO to boost its photocatalytic performance. We achieved the Z-scheme structure by hydrothermal modification of SnS2 nanoparticles onto ZnO microspheres. Its photocatalytic performance was evaluated through the degradation of Rhodamine B (RhB) under visible light with the assistance of magnetic stirring. The composite photocatalyst exhibited superior performance compared to individual ZnO and SnS2, achieving an optimal degradation rate of 0.0706 min⁻¹. This rate was 15.08 times higher than that of individual ZnO and 10.51 times higher than individual SnS2. Free radical trapping experiments showed that ·O2⁻ and ·OH radicals played a key role in RhB degradation. The Z-scheme composite structure established novel charge transport pathways, guided the migration of photogenerated carriers, and improved spatial separation, thereby enhancing photocatalytic performance. This study provides valuable insights into the design of highly efficient photocatalysts for environmental remediation, offering a promising solution for addressing challenges in pollution control and wastewater treatment.

Molecular doping of graphitic carbon nitride for enhanced visible light-driven photodegradation of organic contaminants

Utilizing solar energy for photodegradation of organic contaminants is an attractive strategy for environmental remediation. However, the synthesis of photocatalysts for efficient use of solar energy remains a challenge. Herein, we designed and synthesized a hierarchical and porous g-C3N4 (CN) via thermal polymerization of 5-amino-1H-tetrazole (ATZ) and melamine molecules. Experimental results demonstrate that the incorporation of electron-deficient ATZ into the CN structure drastically promotes the separation and transport of photoexcited charge carriers, and increases the specific surface area and pore size of the sample. Based on these unique features, the optimal CN-ATZ1 sample exhibited excellent photocatalytic activity with a rate constant of 0.091 min−1 for the degradation of rhodamine B (RhB) under visible light irradiation, which was about 10.71 times higher than that of bulk CN. Radical trapping experiments demonstrate that the superoxide radical (•O2−) is the major active species during the photodegradation process. This study provides a feasible strategy for the design and construction of g-C3N4 photocatalysts with high degradation activity.

Template Synthesis of Iodocuprate and Iodoargentate with Photocatalytic Activity and Second Harmonic Generation Efficiency.

In virtue of the cationic tri(pyridin-4-yl)amine (TPA) derivatives acting as the templates, two iodometallates, [Me3HTPA]2[CuI3][Cu10I16] (1) and [Me3TPA][Ag5I8] (2), were constructed with different architectures. Compound 1 features a discrete [Cu10I16]6- cluster, which is further combined with [CuI3]2- and two [Me3HTPA]4+ moieties through electrostatic interactions to result in a 3D supramolecular framework. Two types of infinite Ag-I chains with different orientations are formed in iodoargentate 2, and adjacent chains, together with in situ N-methylated cations, are further aggregated into a final 3D supramolecule. The syntheses, crystal structures, and optical properties have been studied. Notably, compound 1 displays efficient visible-light-driven photocatalytic performance for the degradation of dye pollutants. The catalytic mechanism was investigated through radical trapping experiments as well as theoretical calculations. Moreover, both the iodocuprate and iodoargentate hybrids exhibit second harmonic generation (SHG) effects, which are comparable to and even better than that of KH2PO4, indicating that the iodometallate hybrids templated by TPA-based cations could potentially serve as new candidates for second-order nonlinear optics (NLO) materials.

Nonenzymatic Hydration of Phosphoenolpyruvate: General Conditions for Hydration in Protometabolism by Searching Across Pathways.

Numerous reactions within metabolic pathways have been reported to occur nonenzymatically, supporting the hypothesis that life arose upon a primitive nonenzymatic precursor to metabolism. However, most of those studies reproduce individual transformations or segments of pathways without providing a common set of conditions for classes of reactions that span multiple pathways. In this study, we search across pathways for common nonenzymatic conditions for a recurring chemical transformation in metabolism: alkene hydration. The mild conditions that we identify (Fe oxides such as green rust) apply to all hydration reactions of the rTCA cycle and gluconeogenesis, including the hydration of phosphoenolpyruvate (PEP) to 2-phosphoglycerate (2PGA), which had not previously been reported under nonenzymatic conditions. Mechanistic insights were obtained bystudying analogous substrates and through anoxic and radical trapping experiments. Searching for nonenzymatic conditions across pathways provides a complementary strategy to triangulate conditions conducive to the nonenzymatic emergence of a protometabolism.

Nonenzymatic Hydration of Phosphoenolpyruvate: General Conditions for Hydration in Protometabolism by Searching Across Pathways

Numerous reactions within metabolic pathways have been reported to occur nonenzymatically, supporting the hypothesis that life arose upon a primitive nonenzymatic precursor to metabolism. However, most of those studies reproduce individual transformations or segments of pathways without providing a common set of conditions for classes of reactions that span multiple pathways. In this study, we search across pathways for common nonenzymatic conditions for a recurring chemical transformation in metabolism: alkene hydration. The mild conditions that we identify (Fe oxides such as green rust) apply to all hydration reactions of the rTCA cycle and gluconeogenesis, including the hydration of phosphoenolpyruvate (PEP) to 2‐phosphoglycerate (2PGA), which had not previously been reported under nonenzymatic conditions. Mechanistic insights were obtained by studying analogous substrates and through anoxic and radical trapping experiments. Searching for nonenzymatic conditions across pathways provides a complementary strategy to triangulate conditions conducive to the nonenzymatic emergence of a protometabolism.

Sequence-Defined Synthesis Enabled by Fast and Living Anionic Monoaddition of Vinyl Monomers.

The selective monoaddition of polymerizable vinyl monomers like styrenes and methacrylates in a living manner has been achieved for the flash-flow preparation of molecules in a defined sequence with high selectivity. We demonstrated the sequence-defined synthesis of multifunctional molecules using an initiator, functionalized styrenes, diarylethylenes, various methacrylates, and an electrophilic trapping reagent at the living terminus (six-component sequential connection at maximum) without any intermediate purification steps. The anionic living terminus of the vinyl monomers in the flow system described herein is active for polymerization, such that the styrene or methacrylate sequence can be expanded to afford highly dispersed oligomers without affecting other single units, which means that the unequivocal sequences were successfully inserted into the internal or terminal positions. The methodology described herein provides an adaptable method for the construction of new molecular spaces based on unimolecular sequence control and pinpoint functionalization.

Sequence‐Defined Synthesis Enabled by Fast and Living Anionic Monoaddition of Vinyl Monomers

AbstractThe selective monoaddition of polymerizable vinyl monomers like styrenes and methacrylates in a living manner has been achieved for the flash‐flow preparation of molecules in a defined sequence with high selectivity. We demonstrated the sequence‐defined synthesis of multifunctional molecules using an initiator, functionalized styrenes, diarylethylenes, various methacrylates, and an electrophilic trapping reagent at the living terminus (six‐component sequential connection at maximum) without any intermediate purification steps. The anionic living terminus of the vinyl monomers in the flow system described herein is active for polymerization, such that the styrene or methacrylate sequence can be expanded to afford highly dispersed oligomers without affecting other single units, which means that the unequivocal sequences were successfully inserted into the internal or terminal positions. The methodology described herein provides an adaptable method for the construction of new molecular spaces based on unimolecular sequence control and pinpoint functionalization.

Construction of Bi2MoO6 sheets/NH2-UiO-66(Zr) heterojunction photocatalysts toward enhanced degradation of tetracycline under visible light

The application of photocatalysts in environmental field has emerged as a prominent research topic. Nevertheless, the efficiency of photocatalysts is reduced as the recombination of photogenerated chargers significantly, restricting their extensive use in this domain. In the present study, photocatalysts composed of bismuth molybdate/NH2-UiO-66(Zr) (Bi2MoO6/NH2-UiO-66(Zr)) featuring Z-scheme heterojunctions were effectively synthesized using a two-step hydrothermal technique. These photocatalysts exhibit remarkable photocatalytic degradation under visible light conditions. Notably, the broad planar configuration of Bi2MoO6 sheets improves the separation of the photogenerated charge carriers. NH2-UiO-66(Zr) layered atop Bi2MoO6 sheets enhances the availability of catalytically active sites, reduces charge recombination, and promotes charge transfer through the interface. The kinetic rate constant for Bi2MoO6/NH2-UiO-66(Zr) is around 0.00329 L mg−1 min−1, indicating the increase of 3.78 and 41.13 times compared with pure Bi2MoO6 and NH2-UiO-66(Zr), respectively. The efficiency for photocatalytic degradation of tetracycline using Bi2MoO6/NH2-UiO-66(Zr) reaches 81.72 % under visible light. Importantly, this efficiency exhibits a reduction of 10 % after five recycling cycles, demonstrating notable stability. The photocatalytic mechanism involved in tetracycline degradation was uncovered through trapping experiments and EPR, indicating that it is predominantly facilitated by the active oxidation of ·O2- and ·OH. The intermediates of the photocatalytic process as well as the possible degradation pathways were discussed. The creation of Bi2MoO6 sheets/NH2-UiO-66(Zr) heterojunction photocatalysts provides a fresh approach to the development of novel catalysts, which may lead to significant advancements in environmental remediation efforts.

Development of an operational trap for collection, killing, and preservation of triatomines (Hemiptera: Reduviidae): the kissing bug kill trap.

Surveillance of triatomines or kissing bugs (Hemiptera: Reduviidae: Triatominae), the insect vectors of Trypanosoma cruzi, a Chagas disease agent, is hindered by the lack of an effective trap. To develop a kissing bug trap, we made iterative improvements over 3 years on a basic design resulting in 7 trap prototypes deployed across field sites in Texas, United States and Northern Mexico, yielding the capture of 325 triatomines of 4 species (Triatoma gerstaeckeri [Stål], T. sanguisuga [LeConte], T. neotomae [Neiva], and T. rubida [Uhler]). We began in 2019 with vertical transparent tarpaulin panel traps illuminated with artificial light powered by AC current, which were successful in autonomous trapping of flying triatomines, but were expensive, labor-intensive, and fragile. In 2020, we switched to white LED lights powered by a solar cell. We tested a scaled-down version of the vertical panel traps, a commercial cross-vane trap, and a multiple-funnel trap. The multiple-funnel traps captured 2.6× more kissing bugs per trap-day than cross-vane traps and approached the performance of the vertical panel traps in number of triatomines captured, number of triatomines per trap-day and triatomines per arthropod bycatch. Multiple-funnel traps required the least labor, were more durable, and had the highest triatomines per day per cost. Propylene glycol in the collection cups effectively preserved captured triatomines allowing for molecular detection of T. cruzi. The trapping experiments established dispersal patterns for the captured species. We conclude that multiple-funnel traps with solar-powered LED lights should be considered for adoption as surveillance and potentially mass-trapping management tools for triatomines.

Carbazolyl-Decorated Metal-Organic Framework with a High Fluorescent Quantum Yield for Detection and Photocatalytic Degradation of Organic Contaminants.

A carbazolyl-based fluorescent metal-organic framework with deep-blue light emission and a high quantum yield (88%) has been screened out by changing the ratio of mixed ligands, named Cz-MOF-2, which was constructed by ZrO4(OH)4 clusters, 3-(9-ethyl-9H-carbazol-3-yl)-4-methylthieno[2,3-b]thiophene-2,5-dicarboxylate (H2ECMTDC) and 3,4-dimethyl-dihydrothieno[2,3-b]thiophene-2,5-dicarboxylate (H2DMTDC). Cz-MOF-2 has excellent sensitivity in fluorescent sensing of 2,6-dichloro-4-nitroaniline (DCN), nitrofurazone (NZF), and nitrofurantoin (NFT) with detection limits of 3.37 × 10-7, 1.64 × 10-5, and 1.76 × 10-5 M, respectively. The quenching mechanisms involving electron transfer and competitive absorption were comprehensively elucidated through DFT calculations and UV absorption experiments. Cz-MOF-2 has been fabricated into a rapidly regenerated composite membrane with PVDF as a visualized fluorescent sensor for DCN. Furthermore, the carbazolyl groups covalently modified in the framework endowed Cz-MOF-2 with a suitable band gap (2.58 eV) for photocatalytic degradation of organic contaminants. It demonstrated superior photocatalytic efficiency compared to UiO-66 and NH2-UiO-66 in the degradation of tetracycline (TC), and the removal efficiency was up to 85% (20 mg of catalyst, 50 mL, 20 mg/L TC solution and 180 min) under simulated sunlight irradiation using a 300 W Xe lamp. Photoelectrochemical tests demonstrate that Cz-MOF-2 exhibits high photocurrent density and low charge transfer resistance, which provide evidence for the efficient charge separation capability. Radical trapping experiments and ESR detection have substantiated that ·O2- and h+ are the primary active species involved in this photocatalytic reaction. This work highlights the potential of MOFs in the targeted design and development of fluorescent sensors and photocatalysts for environmental detection and remediation.

Establishing robust ZnO-sodium alginate nanocomposite for dye wastewater treatment: characterization, RSM methodology, and mechanism evaluation.

In today's world, water is a highly valued resource, and enhancing the quality of this natural endowment is a significant concern and a worldwide endeavor. This study sought to purify real wastewater and water tainted with methylene blue (MB) by immobilizing ZnO nanoparticles onto an alginate matrix using a straightforward approach and a three-dimensional structure. After analyzing the impact of , it was determined that 93.84% of MB was successfully removed (time = 120 min, dye concentration = 15 mg/L, catalyst amount = 2.5 g). The effects of inorganic ions and water types were investigated to simulate real wastewater conditions, and the catalyst performed satisfactorily. Alginate played a significant role in selectively removing dye, and the catalyst effectively removed 80.36% of MB and, in contrast, 20% of methyl orange (MO). The practical application of the catalyst was evaluated in textile wastewater treatment, and the catalyst showed satisfactory performance. An average 2.49% reduction in dye removal was observed after five stages of using the catalyst, demonstrating the beads' excellent stability. The composites were subjected to free radical trapping experiments to ascertain the active species. According to the results, and acted as the main reaction species in the degradation of MB. At the end, the synergistic mechanism of adsorption and degradation in MB removal was presented.

Efficient Loading into and Controlled Release of Lipophilic Compound from Liposomes by Using Cyclodextrin as Novel Trapping Agent.

Lipid bilayer vesicles, liposomes are representative drug delivery carriers. High encapsulation efficiency and release control of drugs are essential for clinical application of liposomes. For efficient drug loading into liposomes, remote loading method using driving force like transmembrane gradients of pH and ions are utilized. Ions are called as "trapping agents," which are also critical for the controlled release of drugs loaded into liposomes inside. It is difficult to apply ions as trapping agents to various drugs because of limited physicochemical compatibility between drugs and ions. Cyclodextrins (CDs) with hydrophobic cavity can make inclusion complexes with various hydrophobic compounds. Therefore, we aimed to evaluate the potential of CDs as a novel trapping agent using sulfobutylether-β-cyclodextrin (SBE-β-CD) and ibuprofen (IB), a weak acid hydrophobic drug. Encapsulation efficiency of IB in liposomes with pH gradient was approximately 27%, and it was enhanced by intraliposomal SBE-β-CD inclusion in addition to pH gradient, which was SBE-β-CD concentration-dependent. In liposomes with pH gradient, a large fraction of IB was released in a short time. This early-stage rapid IB release was significantly suppressed by the inclusion of SBE-β-CD inside liposomes. Thus, novel remote loading technology by intraliposomal SBE-β-CD enabled the efficient encapsulation of the hydrophobic drug into the aqueous phase of liposomes as well as their controlled release. This technology should be applied to various drugs that can be included into CDs in order to enhance their therapeutic benefits.

Efficient tetracycline degradation using carbon quantum dot modified TiO2@LaFeO3 hollow core shell photocatalysts

Efficient harnessing of solar energy presents a significant challenge in environmental cleanup efforts. This study develops a highly effective carbon quantum dots-modified hollow core-shell TiO2-LaFeO3 heterojunction photocatalyst (CDs-TLFO). Structural analysis confirmed that nanosheets are loaded with CQDs, forming a hollow core-shell structure with intimate interconnection. Photocatalytic experiments reveal that CDs-TLFO degrads tetracycline hydrochloride (TC) 2.02 times faster than TLFO alone, and significantly outperformes h-TiO2 and LaFeO3 (11.28 and 2.78 times, respectively). This enhancement is attributed to CQDs acting as electron acceptors with upconversion properties, enhancing the separation of e–-h+ pairs and boosting visible light absorption. Integration of CQDs onto the TLFO surface creates numerous active sites and enhances visible light absorption. SEM and TEM tests confirm that the catalyst has a hollow core-shell structure. ESR tests and radical trapping experiments indicate that the high degradation efficiency of the catalyst mainly owns to the synergistic effect of hydroxyl radicals (·OH) and superoxide radicals (·O2−). The reusability and stability of the catalysts are investigated, potential TC degradation pathways are proposed as well as the photocatalytic reaction mechanism is revealed. This research introduces promising avenues for environmental cleanup and offers a straightforward, energy-efficient, and environmentally friendly method for producing CDs-TLFO heterojunction materials with superior photocatalytic capabilities.

Inverse opal TiO2-CdS photonic crystal beads with slow light effect for photocatalytic degradation

Photocatalytic oxidation technology using solar energy is an effective strategy to solve environmental pollution and energy shortage. To avoid angle dependence of traditional photonic crystal photocatalysts and address the limitations of high charge recombination rate and low light utilization of TiO2, this study proposed a novel inverse opal TiO2/CdS photonic crystal beads (IO TiO2/CdS PCBs) photocatalyst. By leveraging the synergistic coupling of PCBs’ slow light effect and TiO2/CdS heterojunction, the photocatalytic activity was significantly enhanced. The results revealed that the PCBs matching the blue edge with TiO2′s electronic band gap (IO TiO2-140 PCBs) exhibited the highest apparent rate constant of 0.01901 min−1. By introducing CdS to form a heterojunction with TiO2, the photocatalytic performance was further improved by effectively inhibiting the recombination of photogenerated carriers. The degradation rate of RhB reached 96.6 % in 60 min, outperforming that of IO TiO2 at 65.1 %, with the rate constant increasing by 3.1 times. Electron spin resonance and trapping experiments indicated that h+ was the main active specie, and the possible reaction mechanism path was proposed. The combination of “extrinsic” modifications by doping CdS and “self-structural” modifications by shaping TiO2 into periodic IO PCBs structure provided a systematic insight on the design of novel photocatalysts.