Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 45
Filter
1.
Small ; 20(30): e2311504, 2024 Jul.
Article in English | MEDLINE | ID: mdl-38412431

ABSTRACT

Herein, guided by the results of density functional theory prediction, the study rationally designs a hollow core-shell FeNi2S4@ZnIn2S4 (FNS@ZIS) Step-scheme (S-scheme) heterojunction for photocatalytic H2 evolution with photothermal-assisted. The hollow FNS spheres offered substrate for coating the ZIS nanosheets, which can inhibit ZIS nanosheets from agglomerating into pellet, enrich the active site, increase specific surfaces, and raise the light absorption. Notably, due to its excellent photothermal properties, FNS core generated heat unceasingly inside under visible-light irradiation and effectively prevent the heat loss of the reaction system, which increased the local temperature of photocatalysts and thus accelerated the charge migration. In addition, the S-scheme heterojunction construction via in situ growth has a tight interface, which can facilitate the separation and transfer of carriers and achieve high redox potential. Owning to the distinctive construction, the hollow core-shell FNS@ZIS S-scheme heterojunction show extraordinary stability and photocatalytic H2 evolution rate with 7.7 mmol h-1 g-1, which is ≈15.2-fold than pristine ZIS. Based on the double evidence of theoretical predictions and experimental confirmations, the photothermal effect and electron transfer mechanism of this innovative material are investigated in depth by the following infrared thermography technology and deep DFT calculations.

2.
Sensors (Basel) ; 23(9)2023 Apr 24.
Article in English | MEDLINE | ID: mdl-37177444

ABSTRACT

Currently, infrared small target detection and tracking under complex backgrounds remains challenging because of the low resolution of infrared images and the lack of shape and texture features in these small targets. This study proposes a framework for infrared vehicle small target detection and tracking, comprising three components: full-image object detection, cropped-image object detection and tracking, and object trajectory prediction. We designed a CNN-based real-time detection model with a high recall rate for the first component to detect potential object regions in the entire image. The KCF algorithm and the designed lightweight CNN-based target detection model, which parallelly lock on the target more precisely in the target potential area, were used in the second component. In the final component, we designed an optimized Kalman filter to estimate the target's trajectory. We validated our method on a public dataset. The results show that the proposed real-time detection and tracking framework for infrared vehicle small targets could steadily track vehicle targets and adapt well in situations such as the temporary disappearance of targets and interference from other vehicles.

3.
Langmuir ; 36(25): 6930-6937, 2020 Jun 30.
Article in English | MEDLINE | ID: mdl-31604011

ABSTRACT

The light-driven micromotor has been demonstrated to have great potential in the environmental remediation field. However, it is still challenging to develop highly efficient, ecofriendly, and visible-light-powered micromotors for organic pollutant degradation. In this paper, we report an ecofriendly micromotor based on iron phthalocyanine (FePc) and gelatin, which exhibits the visible-light-driven self-propulsion behavior using water fuel based on the photocatalytic reaction and self-diffusiophoresis mechanism. Fast motion behavior is observed which induces the rapid agitation of the solution. This, together with the excellent photocatalytic activity, makes the FePc-based micromotor highly efficient when utilized in the degradation of organic pollutants with a normalized reaction rate constant of 2.49 × 10-2 L m-2 s-1, which is by far the fastest and is far superior than the stationary counterpart. The external fuel-free propulsion and the high efficiency in pollutant degradation make the current micromotor potentially attractive for environmental remediation.

4.
Nanotechnology ; 31(30): 305701, 2020 Jul 24.
Article in English | MEDLINE | ID: mdl-32272459

ABSTRACT

Efficient and noble metal-free co-catalyst loading is an effective solution for separating and transferring photo-generated carriers and lowering the overpotential in photocatalytic H2 evolution activity. In this work, we designed and prepared a series of novel NiCoP/Mn0.3Cd0.7S (NCP/MCS) composites by modifying MCS nanorods with the co-catalyst NCP using a simple calcination method. Notably, the 10-NCP/MCS composite displays the optimum photocatalytic H2 evolution rate of 118.5 mmol g-1 h-1 under visible-light irradiation. This is approximately 3.39 times higher than that of pure MCS. The corresponding apparent quantum efficiency is 10.2% at 420 nm. The superior photocatalytic activity of the NCP/MCS composites can be attributed to the efficient separation of photogenerated carriers caused by the intimate heterojunction interface between NCP and MCS, smaller transfer resistance, and lower overpotential of NCP. Moreover, the NCP/MCS composites exhibit remarkable photostability. A plausible mechanism is proposed.

5.
Biochem Biophys Res Commun ; 509(2): 483-490, 2019 02 05.
Article in English | MEDLINE | ID: mdl-30595386

ABSTRACT

Oxidative stress (OS)-induced apoptosis of periodontal ligament cells (PDLCs) has been suggested to be an important pathogenic factor of periodontitis. Mitochondrial abnormalities are closely linked to OS and act as the main players in apoptosis. Our aim was to investigate the potential mitochondrial abnormalities in PDLCs apoptosis induced by OS. In this study, significant reduction in viability and increased apoptosis were observed in H2O2-treated hPDLCs. H2O2 also induced mitochondrial dysfunction, judging by increased mitochondrial reactive oxygen species amounts, and decreased mitochondrial membrane potential as well as ATP levels. Furthermore, H2O2 significantly enhanced mitochondrial fission by decreasing the expression of Mfn1 and Mfn2, along with increasing the expression of Drp1, Fis1 and the cleavage of OPA1. Notably, NAC stabilized the balance of the mitochondrial dynamics, attenuated mitochondrial dysfunction, and inhibited apoptosis of hPDLCs in the presence of H2O2. In conclusion, the OS-induced apoptosis of hPDLCs may be mediated by mitochondria-dependent pathway.


Subject(s)
Fibroblasts/pathology , Mitochondria/pathology , Oxidative Stress , Periodontal Ligament/pathology , Acetylcysteine/pharmacology , Adult , Cell Survival/drug effects , Cells, Cultured , Fibroblasts/cytology , Fibroblasts/drug effects , Fibroblasts/metabolism , Free Radical Scavengers/pharmacology , Humans , Hydrogen Peroxide/metabolism , Male , Membrane Potential, Mitochondrial/drug effects , Mitochondria/drug effects , Mitochondria/metabolism , Mitochondrial Dynamics/drug effects , Oxidative Stress/drug effects , Periodontal Ligament/cytology , Periodontal Ligament/drug effects , Periodontal Ligament/metabolism , Young Adult
6.
Langmuir ; 35(7): 2801-2807, 2019 Feb 19.
Article in English | MEDLINE | ID: mdl-30688463

ABSTRACT

In this paper, we report a novel multi-responsive walnut-like micromotor consisting of polycaprolactone (PCL), iron oxide nanoparticles (Fe3O4 NPs), and catalase, which is constructed through a one-step electrospinning method. Based on the catalytic activity and photothermal and magnetic responsiveness originating from catalase and Fe3O4 NPs, respectively, the resulting micromotor exhibits an autonomous movement in the presence of hydrogen peroxide (H2O2) fuel, controlled motion velocity under light irradiation, and guided movement direction upon the application of an external magnetic field. Owing to the hydrophobic nature of the PCL polymer constituent inside the micromotor, the autonomous moving micromotor can collect spilled oil inside a solution once it collides with the oil droplet. Since the micromotor could be separated out using a magnetic field, we believe the current walnut-like micromotor holds great promise in the field of environmental remediation.

7.
Cell Physiol Biochem ; 41(2): 661-677, 2017.
Article in English | MEDLINE | ID: mdl-28291961

ABSTRACT

BACKGROUND: Osteoblast apoptosis induced by oxidative stress plays a crucial role in the development and progression of osteoporosis. Curcumin, a natural antioxidant isolated from Curcuma longa, has highly protective effects against osteoporosis. However, the effects of curcumin on oxidative stress-induced osteoblast apoptosis remain unclear. This study aimed to explore the effect of curcumin on hydrogen peroxide (H2O2) induced osteoblast apoptosis and the underlying mechanisms. METHODS: An osteoblastic cell line (Saos-2) was exposed to various concentrations of H2O2 with or without curcumin treatment. Cell viability was evaluated by MTT assays. The apoptosis rate was analyzed by flow cytometry and TUNEL assays. Mitochondrial ROS and membrane potential were determined using a fluorescence microscope. Mitochondrial respiratory enzyme activity was measured using a spectrophotometer. Protein levels were detected by western blotting. RESULTS: Curcumin was cytoprotective because it greatly improved the viability of Saos-2 cells exposed to H2O2 and attenuated H2O2-induced apoptosis. Curcumin treatment also preserved the mitochondrial redox potential, decreased the mitochondrial oxidative status, and improved the mitochondrial membrane potential and functions. Furthermore, curcumin treatment markedly increased levels of phosphorylated protein kinase B (Akt) and phosphorylated glycogen synthase kinase-3ß (GSK3ß). CONCLUSION: Curcumin administration ameliorates oxidative stress-induced apoptosis in osteoblasts by preserving mitochondrial functions and activation of Akt-GSK3ß signaling. These data provide experimental evidence supporting the clinical use of curcumin for prevention or treatment of osteoporosis.


Subject(s)
Apoptosis/drug effects , Curcumin/pharmacology , Mitochondria/metabolism , Oxidative Stress/drug effects , Signal Transduction/drug effects , Antioxidants/pharmacology , Caspase 3/metabolism , Cell Line , Cell Survival/drug effects , Glycogen Synthase Kinase 3 beta/metabolism , Humans , Hydrogen Peroxide/toxicity , Membrane Potential, Mitochondrial/drug effects , Microscopy, Fluorescence , Mitochondria/drug effects , Organometallic Compounds/pharmacology , Osteoblasts/cytology , Osteoblasts/drug effects , Osteoblasts/metabolism , Phosphorylation/drug effects , Proto-Oncogene Proteins c-akt/metabolism , Proto-Oncogene Proteins c-bcl-2/metabolism , Reactive Oxygen Species/metabolism , Salicylates/pharmacology
8.
Nanotechnology ; 27(38): 385602, 2016 Sep 23.
Article in English | MEDLINE | ID: mdl-27518499

ABSTRACT

A novel simple method was proposed to synthesize BiOCl/Bi2Sn2O7 heterojunction photocatalysts through the treatment of Bi2Sn2O7 with HCl solution of different concentrations. The as-synthesized photocatalysts were characterized by x-ray diffraction, scanning electron microscopy, transmission electron microscopy, photoluminescence, x-ray photoelectron spectroscopy and ultraviolet-visible diffuse reflectance spectroscopy. The experimental results show that sheet-like BiOCl particles were obtained after the HCl treatment. Bi2Sn2O7 nanoparticles were distributed on the BiOCl sheets, resulting in the low aggregation of the Bi2Sn2O7 nanoparticles. As compared to BiOCl and Bi2Sn2O7, BiOCl/Bi2Sn2O7 showed enhanced photocatalytic activity under visible light irradiation, which can be attributed to the effective separation of photogenerated electrons and holes due to the formation of a BiOCl/Bi2Sn2O7 heterojunction. In addition, the dominant active species and the photocatalytic mechanism were discussed in detail.

9.
Pharmacology ; 97(5-6): 218-23, 2016.
Article in English | MEDLINE | ID: mdl-26872133

ABSTRACT

The aim of this study was to assess the influence of evodiamine on the activities of the drug-metabolizing enzymes cytochrome P450 (CYP) 1A2, CYP2C9, CYP2C19, CYP2D6 and CYP3A4 in rats. The activities of CYP1A2, CYP2C9, CYP2C19, CYP2D6 and CYP3A4 were measured using specific probe drugs. After pretreatment for 1 week with evodiamine or physiological saline (control group) by oral administration, probe drugs phenacetin (5.0 mg/kg; CYP1A2 activity), tolbutamide (1.0 mg/kg; CYP2C9 activity), omeprazole (10 mg/kg; CYP2C19 activity), metoprolol (20 mg/kg; CYP2D6 activity) and midazolam (10 mg/kg; CYP3A4 activity) were administered to rats by oral administration. The blood was then collected at different times for ultra-performance liquid chromatography-tandem mass spectrometry analysis. The data showed that evodiamine exhibits an inhibitory effect on CYP1A2, CYP2C9 and CYP2D6 by increasing t(1/2), Cmax and AUC(0-∞), and decreasing CL/F compared with those of the control group. However, no significant changes in CYP2C19 and CYP3A4 activities were observed. In conclusion, the results indicated that evodiamine could inhibit CYP1A2, CYP2C9 and CYP2D6, which may affect the disposition of medicines primarily dependent on these pathways. Our work may be the basis of related herb-drug interactions in the clinic.


Subject(s)
Cytochrome P-450 Enzyme Inhibitors/pharmacology , Cytochrome P-450 Enzyme System/metabolism , Herb-Drug Interactions , Quinazolines/pharmacology , Administration, Oral , Animals , Liver/drug effects , Liver/metabolism , Male , Metoprolol/blood , Metoprolol/pharmacokinetics , Midazolam/blood , Midazolam/pharmacokinetics , Omeprazole/blood , Omeprazole/pharmacokinetics , Phenacetin/blood , Phenacetin/pharmacokinetics , Rats, Sprague-Dawley , Tolbutamide/blood , Tolbutamide/pharmacokinetics
10.
Bioorg Med Chem Lett ; 25(7): 1541-5, 2015 Apr 01.
Article in English | MEDLINE | ID: mdl-25724825

ABSTRACT

A series of 5,6,7-trimethoxyflavone-6-chlorotacrine hybrids were designed, synthesized and evaluated as multifunctional agents for the treatment of Alzheimer's disease (AD). The results showed that the target compounds exhibited good acetylcholinesterase (AChE) inhibitory potencies, high selectivity toward AChE over butyrylcholinesterase (BuChE), potential antioxidant activities and significant inhibitory potencies of self-induced beta-amyloid peptide (Aß) aggregation. In particular, compound 14c had the strongest AChE inhibitory activity with IC50 value of 12.8 nM, potent inhibition of self-induced Aß1-42 aggregation with inhibition ratio of 33.8% at 25 µM. Moreover, compound 14c acted as an antioxidant, as well as a neuroprotectant. Furthermore, 14c could cross the blood-brain barrier (BBB) in vitro. The results showed that compound 14c might be a potential multifunctional candidate for the treatment of AD.


Subject(s)
Alzheimer Disease/drug therapy , Antioxidants/pharmacology , Cholinesterase Inhibitors/pharmacology , Drug Design , Flavones/pharmacology , Tacrine/analogs & derivatives , Acetylcholinesterase/metabolism , Animals , Antioxidants/chemical synthesis , Antioxidants/chemistry , Butyrylcholinesterase/metabolism , Cell Survival/drug effects , Cholinesterase Inhibitors/chemical synthesis , Cholinesterase Inhibitors/chemistry , Dose-Response Relationship, Drug , Electrophorus , Equidae , Flavones/chemical synthesis , Flavones/chemistry , Molecular Structure , PC12 Cells , Rats , Structure-Activity Relationship , Tacrine/chemical synthesis , Tacrine/chemistry , Tacrine/pharmacology
11.
Med Sci Monit ; 20: 2527-35, 2014 Dec 04.
Article in English | MEDLINE | ID: mdl-25472588

ABSTRACT

BACKGROUND: MicroRNA-32 (miR-32) is dysregulated in certain human malignancies and correlates with tumor progression. However, its expression and function in oral squamous cell carcinoma (OSCC) remain unclear. Thus, the aim of this study was to explore the effects of miR-32 expression on OSCC tumorigenesis and development. MATERIAL/METHODS: Real-time quantitative PCR was applied to evaluate the expression level of miR-32 in OSCC cell lines and primary tumor tissues. The association of miR-32 expression with clinicopathological factors and prognosis was also analyzed. In vitro cell proliferation, apoptosis, invasion, and migration assays were executed to elucidate biological effects of miR-32. Western blotting and luciferase assays were performed to confirm the regulation of EZH2 by miR-32. RESULTS: Down-regulation of miR-32 was found in OSCC tissues compared with corresponding noncancerous tissues (P<0.001). Decreased miR-32 expression was significantly associated with advanced T classifications, positive N classification, advanced TNM stage, and shorter overall survival (all P<0.05). Multivariate regression analysis corroborated that low-level expression of miR-32 was an independent unfavorable prognostic factor for OSCC patients. In vitro functional assays showed that overexpression of miR-32 reduced OSCC cell proliferation, migration, and invasion, and promoted cell apoptosis. In contrast, miR-32 knock-down resulted in an increase in cell growth and invasiveness. Finally, we identified EZH2 as the functional downstream target of miR-32 by directly targeting the 3'-UTR of EZH2. CONCLUSIONS: These findings indicate that miR-32 may act as a tumor suppressor in OSCC and could serve as a novel therapeutic agent for miR-based therapy.


Subject(s)
Carcinoma, Squamous Cell/genetics , Genes, Tumor Suppressor , MicroRNAs/metabolism , Mouth Neoplasms/genetics , Polycomb Repressive Complex 2/genetics , Base Sequence , Carcinoma, Squamous Cell/pathology , Cell Line, Tumor , Enhancer of Zeste Homolog 2 Protein , Female , Gene Expression Regulation, Neoplastic , Humans , Male , MicroRNAs/genetics , Middle Aged , Molecular Sequence Data , Mouth Neoplasms/pathology , Multivariate Analysis , Polycomb Repressive Complex 2/metabolism , Survival Analysis , Transfection
12.
Med Sci Monit ; 20: 163-6, 2014 Jan 31.
Article in English | MEDLINE | ID: mdl-24487779

ABSTRACT

Titanium is widely used in biomedical materials, particularly in dental implants, because of its excellent biocompatibility and mechanical characteristics. However, titanium implant failures still remain in some cases, varying with implantation sites and patients. Improving its overall performance is a major focus of dental implant research. Equal-channel angular pressing (ECAP) can result in ultrafine-grained titanium with superior mechanical properties and better biocompatibility, which significantly benefits dental implants, and without any harmful alloying elements. Lanthanum (La) can inhibit the acidogenicity of dental plaque and La-containing hydroxyapatite (La-HA) possesses a series of attractive properties, in contrast to La-free HA. Micro-arc oxidation (MAO) is a promising technology that can produce porous and firmly adherent hydroxyapatite (HA) coatings on titanium substrates. Therefore, we hypothesize that porous La-containing hydroxyapatite coatings with different La content (0.89%, 1.3% and 1.79%) can be prepared on ultrafine-grained (~200-400 nm) titanium by ECAP and MAO in electrolytic solution containing 0.2 mol/L calcium acetate, 0.02 mol/L beta-glycerol phosphate disodium salt pentahydrate (beta-GP), and lanthanum nitrate with different concentrations to further improve the overall performance of titanium, which are expected to have great potential in medical applications as a dental implant.


Subject(s)
Biocompatible Materials/chemistry , Dental Implants , Durapatite/chemistry , Lanthanum/chemistry , Titanium/chemistry , Titanium/standards , Durapatite/analysis , Humans , Materials Testing , Oxidation-Reduction , Porosity , Surface Properties , Titanium/therapeutic use
13.
J Colloid Interface Sci ; 657: 672-683, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38071816

ABSTRACT

Suppressing the electron-hole recombination rate of catalyst legitimately is one of the effective strategies to improve photocatalytic hydrogen evolution. Herein, carbon-coated metal oxide, ZnFe2O4@C (ZFO@C), nanoparticles were synthesized and employed to couple with quadrupedal Cd0.9Zn0.1S (CZS) via an ordinary ultrasonic self-assembly method combined with calcination to form a novel ZFO@C/CZS catalyst with step-scheme (S-scheme) heterojunction. The photocatalytic hydrogen evolution reaction (HER) was conducted to verify the enhanced photoactivity of ZFO@C/CZS. The optimal ZFO@C/CZS exhibits an extraordinary photocatalytic HER rate of 111.3 ± 0.9 mmol g-1 h-1 under visible-light irradiation, corresponding to an apparent quantum efficiency as high as (76.2 ± 0.9)% at 450 nm. Additionally, the as-synthesized ZFO@C/CZS composite exhibits high stability and recyclability. The excellent photocatalytic hydrogen evolution performance should arise from the formed S-scheme heterojunction and the unique ZFO@C core-shell structure, which inhibit electron hole recombination as well as provide more reactive sites. The pathway of S-scheme charge transfer was validated through density functional theory calculations and electrochemical measurements. This work provides a rational strategy for the synthesis of unique magnetic S-scheme heterojunction photocatalysts for water splitting under visible light irradiation.

14.
J Colloid Interface Sci ; 675: 471-480, 2024 Jul 06.
Article in English | MEDLINE | ID: mdl-38986320

ABSTRACT

In addition to the intrinsic driving force of photocatalysis, the external thermal field from the photothermal effect can provide additional energy to the photo-catalytic system to improve the photo-catalytic hydrogen-evolution (PHE) efficiency. Herein, based on the results of density functional theory, we designed and constructed a hollow core-shell FeNi2S4@Mn0.3Cd0.7S (NFS@MCS) S-scheme heterojunction with a photothermal effect, thereby realising a significant enhancement of the PHE performance due to the thermal effect, S-scheme heterojunction and hollow core-shell morphology. As a light collector and heat source, the hollow NFS could absorb and convert photons into heat, resulting in the increased local temperature of photocatalyst particles. Moreover, the S-scheme charge path at the interface not only improved the carrier separation efficiency but also retained a higher redox potential. All these are favourable to increase the PHE activity. The PHE tests show that 0.5 %-NFS@MCS exhibits the highest PHE rate of 17.11 mmol·g-1·h-1, 7.7 times that of MCS. Moreover, through a combination of theoretical calculation and experimental evidence, the PHE mechanism of the NFS@MCS system is discussed and clarified in-depth.

15.
J Colloid Interface Sci ; 673: 463-474, 2024 Nov.
Article in English | MEDLINE | ID: mdl-38878380

ABSTRACT

Rational design of the morphology and heterojunction to accelerate the separation of electron-hole pairs has played an indispensable role in improving the photocatalytic hydrogen evolution. ZnIn2S4 (ZIS) has aroused considerable attention in solar-to-chemical energy conversion due to its remarkable photoelectrical properties and relatively negative energy band, whereas it still suffers from the severe photogenerated carrier recombination and catalyst aggregation. Herein, guided by density functional theory calculations, the constructed FeSe2@ZnIn2S4 (FS@ZIS) heterojunction model has a hydrogen Gibbs free energy closer to zero compared with pure ZIS and FS, which is beneficial for hydrogen adsorption and desorption on the photocatalyst surface. Therefore, a novel cross-like core-shell FS@ZIS Step-scheme (S-scheme) heterojunction was synthesized successfully by in-situ growing ZIS nanosheets on the surface of cross-like FS. The structure with cross-like core-shell morphology not only inhibits the agglomeration of ZIS to increase specific surface area, but also provides a tight interface with S-scheme heterojunction. Moreover, the S-scheme heterojunction with a tight interface can effectively separate electron-hole pairs, leaving photoinduced charges with higher potentials. Furthermore, FS@ZIS-20 possesses exceptional photothermal capabilities, enabling the conversion of optical energy from visible and near infrared light to heat, thereby further enhancing the photocatalysis reaction. As a result, the cross-like core-shell FS@ZIS S-scheme heterojunction exhibits an excellent photocatalytic hydrogen evolution rate (7.640 mmol g-1 h-1), which is 24 times higher than that of pure ZIS (0.319 mmol g-1 h-1) under visible and near infrared light. Furthermore, employing more in-depth density functional theory calculations further investigates the charge transfer pathway of the FS@ZIS S-scheme heterojunction. This work provides insights into the construction of S-scheme heterojunctions with core-shell structure and photothermal effect for photocatalytic evolution hydrogen.

16.
J Colloid Interface Sci ; 662: 276-288, 2024 May 15.
Article in English | MEDLINE | ID: mdl-38354555

ABSTRACT

An emerging approach that employs both light and vibration energy on binary photo-/piezoelectric semiconductor materials for efficient hydrogen (H2) evolution has garnered considerable attention. ZnIn2S4 (ZIS) is recognized as a promising visible-light-activated photocatalyst. However, its effectiveness is constraint by the slow separation dynamics of photoexcited carriers. Density functional theory (DFT) predictions have shown that the integration of piezoelectric BiFeO3 (BFO) is conducive to the reduction of the H2 adsorption free energy (ΔGH*) for the photocatalytic H2 evolution reaction, thereby enhancing the reaction kinetics. Informed by theoretical predictions, piezoelectric BFO polyhedron particles were successfully synthesized and incorporated with ZIS nanoflowers to create a ZIS/BFO heterojunction using an ultrasonic-assisted calcination method. When subjected to simultaneous ultrasonic treatment and visible-light irradiation, the optimal ZIS/BFO piezoelectric enhanced (piezo-enhanced) heterojunction exhibited a piezoelectric photocatalytic (piezo-photocatalytic) H2 evolution rate approximately 6.6 times higher than that of pristine ZIS and about 3.0 times greater than the rate achieved under light-only conditions. Moreover, based on theoretical predictions and experimental results, a plausible mechanism and charge transfer route for the enhancement of piezo-photocatalytic performance were studied by the subsequent piezoelectric force microscopy (PFM) measurements and DFT calculations. The findings of this study strongly confirm that both the internal electric field of the step-scheme (S-Scheme) heterojunction and the alternating piezoelectric field generated by the vibration of BFO can enhance the transportation and separation of electron-hole pairs. This study presents a concept for the multipath utilization of light and vibrational energy to harness renewable energy from the environment.

17.
Chemosphere ; 340: 139777, 2023 Nov.
Article in English | MEDLINE | ID: mdl-37567276

ABSTRACT

Reasonable design of heterojunction photocatalysts with high-quality interfacial coupling is an effective way to improve the photocatalytic activity of semiconductors. Herein, we successfully decorated Zinc indium sulfide (ZnIn2S4, ZIS) on perovskite Lanthanum ferrite (LaFeO3, LFO) with more active sites by a pre-hydrothermal combined post-calcination method, and constructed S-scheme heterojunction photocatalyst with a unique hollow corncob-like morphology for efficient photocatalytic hydrogen production and tetracycline (TC) degradation. When the mass ratio of LFO is 35% and 15%, the ZIS/LFO photocatalyst exhibits the best hydrogen evolution rate and TC photodegradation performance, respectively. Notably, the optimum hydrogen production rate is 6 times that of pure ZIS with excellent cycling stability. The enhanced photoactivity can be explained by the hollow corncob-like morphology and the formed S-scheme heterojunction with close interface contact between ZIS and LFO, which significantly improves the spatial separation and migration efficiency of photoexcited carriers, while maintaining a high redox potential. Finally, it provides an effective support for the photocatalytic mechanism through calculation results of density functional theory. This work not only provides a novel construction strategy of photocatalysts for efficient photocatalytic hydrogen evolution and organic pollutant degradation, but also opens up a new insight for perovskite-modified S-scheme heterojunction.


Subject(s)
Heterocyclic Compounds , Zea mays , Water , Tetracycline , Anti-Bacterial Agents , Hydrogen
18.
Dalton Trans ; 52(41): 14956-14966, 2023 Oct 24.
Article in English | MEDLINE | ID: mdl-37800910

ABSTRACT

The development of efficient and economical photocatalysts is considered a promising strategy for pollution remediation. Magnetically separable SnIn4S8/ZnFe2O4 composites (SIS/ZFO) were prepared by combining SIS with ZFO. The composite with a 30% ZFO mass ratio (SIS/ZFO-30) was the most effective and achieved 60% removal of tetracycline (TC) in 120 min. It has a rate constant of 7.94 × 10-3 min-1, which is 6.3 and 27.2 times higher than those of pure SIS and pure ZFO, respectively. The improved photocatalytic performance can be attributed to the formation of S-scheme heterojunctions between SIS and ZFO, which results in the strong absorption of visible light, the enhanced separation of electron-hole pairs, and the higher redox ability of photoinduced charges. Additionally, SIS/ZFO composites have excellent magnetic properties and high stability, and the recovered samples still retained good photocatalytic degradation performances after four cycles of experiments. Thus, the coupling of SIS with ZFO provides a valuable strategy for enhancing photocatalytic potential and offers a promising pathway for water remediation.

19.
Int J Biol Macromol ; 252: 126253, 2023 Dec 01.
Article in English | MEDLINE | ID: mdl-37562475

ABSTRACT

This study outlines the synthesis of a novel, cost-effective composite material comprising calcium sulphate-modified biochar (Ca-BC) cross-linked with polyethyleneimine (PEI) and sodium alginate (SA), which was subsequently transformed into gel beads (Ca-BC@PEI-SA). These beads were engineered to enable effective cadmium ion (Cd(II)) adsorption from wastewater. Batch adsorption experiments were conducted to evaluate the effects of pH, contact time, temperature, and coexisting ions on adsorption performance. The isotherms and kinetics in the adsorption process were investigated. The results indicated that the removal of Cd(II) by Ca-BC@PEI-SA adheres more closely to the Langmuir model, with maximum adsorption capacities of 138.44 mg/g (15 °C), 151.98 mg/g (25 °C), and 165.56 mg/g (35 °C) at different temperatures. The pseudo-secondary model fit well with Cd(II) adsorption kinetics, suggesting that the removal process was a monolayer process controlled by chemisorption. Moreover, the mechanical strength of the Ca-BC@PEI-SA gel beads allowed easy recovery and reduced secondary contamination. In addition, the adsorption capacity remained nearly constant after four cycles. The main Cd(II) adsorption mechanisms involved surface complexation, ion exchange, and cation-π-bonding interactions.


Subject(s)
Water Pollutants, Chemical , Water Purification , Cadmium/analysis , Wastewater , Calcium Sulfate , Water Purification/methods , Charcoal , Adsorption , Kinetics , Alginates , Water Pollutants, Chemical/analysis , Hydrogen-Ion Concentration
20.
J Colloid Interface Sci ; 650(Pt A): 825-835, 2023 Nov 15.
Article in English | MEDLINE | ID: mdl-37450971

ABSTRACT

The reasonable design and fabrication of heterojunction could regulate the photocatalytic performance to some extent, yet it is still a great challenge to construct the S-scheme heterostructure with the stable as well as tight interface on the surface of semiconductor photocatalysts. Herein, the ZnIn2S4/Cu2MoS4 (ZIS/CMS) S-scheme heterostructure was fabricated by in-situ assembling ZIS nanosheets on the CMS plates, obtaining a mossy tile-like morphology. Owing to the compact interface resulting from in-situ growth, this unique architecture efficiently facilitated the separation and transfer of light-induced charges, guaranteed the larger interface area, and enriched the active sites for photocatalytic redox reactions. After adjusting the mass ratio of CMS in ZIS/CMS, S-scheme heterostructure exhibited the remarkable performance with an optimal H2 producing rate up to 1298 µmol·h-1 g-1, about 13.8 times than that of pristine ZIS. The mechanism and driving force of charge transfer and separation in S-scheme heterostructure photocatalysts were explained and discussed. This investigation will provide new insight into design and construction of S-scheme heterojunction photocatalysts for H2 evolution.

SELECTION OF CITATIONS
SEARCH DETAIL