Molybdenum Disulfide Quantum Dots Research Articles

Mechanochemical synthesis of molybdenum disulfide quantum dots with enhanced dye adsorption and photocatalytic performance

Wet-mechanochemical exfoliation of molybdenum disulfide (MoS2) flakes into MoS2 quantum dots (QDs) using various exfoliation agents is studied, and the photoluminescence, adsorption and photocatalytic activities of QDs toward the degradation of rhodamine B (RhB) are evaluated. The application of ethanol as the low-boiling point (≈78 °C) exfoliation agent leads to the formation of E-MoS2 QDs (4.6 nm) with 1T-crystalline modification, dominately functionalized with hydroxyl groups. Initial MoS2 provides a weak adsorption capacity (27 mg/g), while no photocatalytic activity is observed under LED-light irradiation. E-MoS2 QDs exhibit a poor photocatalytic performance, but an excellent RhB adsorption with an equilibrium capacity of 180 mg/g under dark condition. In contrast, the application of N-Methyl-2-pyrrolidone (NMP) as the high-boiling point (≈202 °C) exfoliation agent leads to the fabrication of N-MoS2 QDs (4.8 nm) with stable 2H-crystalline modification. N-MoS2 QDs exhibits a limited adsorption capacity (32 mg/g), but an excellent stability and photocatalytic performance. At the photocatalyst dosage of 0.1 g/L, the degradation rate of dye (20 mg/L) is recorded at 100 % after 140 min of LED-light (450 nm) illumination. Reusability of N-MoS2 QDs in photocatalysis process is confirmed. Appropriate energy band gap, together with the surface amino/carboxyl functional groups are discussed to be responsible for enhanced light-induced intramolecular electron transfer, thus photocatalytic performance of the material.

In situ growth MoS2 quantum dots as promising interface materials for silicon solar cells

The carrier selectivity at interface is one key factor to improve the performance of silicon solar cells. Here, Molybdenum disulfide (MoS2) quantum dots were successfully synthesized by one-step in situ plasma enhanced atom layer deposition. A transmission electron microscope was employed to investigate nano-size scaled as well as growth mechanism of the crystalline MoS2 quantum dots. MoS2 quantum dots with additional molybdenum-oxygen (Mo–O) bonding were prepared by co-reactant plasma processing, which exhibited photo-generated carrier selectivity as promising interface materials for silicon heterojunction solar cells. Our results indicated their carrier selectivity of electron-blocking and hole-transporting at interface was attributable to unique quantum effects and tunneling effects. A photovoltaic conversion efficiency 23% was achieved by a sample silicon solar cell combined with MoS2 quantum dots interface materials. Because the interface engineering is well-defined, and the synthesis is low-cost, this bottom-up strategy provides a potential advance in design and construction of innovative and highly efficient photovoltaic devices.

Structural Modification in Au-MoS2 Quantum Dot Composites for Improved Catalytic Efficiency in p-Nitrophenol Reduction

Au-MoS2 quantum dots (QDs) composites are ideal catalysts for a number of reactions, including the reduction of p-nitrophenol (PNP). However, the structural role of Au-MoS2 QDs composites in their catalytic efficiency has never been investigated. In this work, a comparative study is carried out to investigate the catalytic reactivities of a gold nanorod–molybdenum disulfide quantum dots (AuNR-MoS2 QDs) composite and a gold nanosphere–molybdenum disulfide quantum dots (AuNS-MoS2 QDs) composite. In addition, the catalytic reactivities of a gold nanorod (AuNR) and a gold nanosphere (AuNS) are also studied. The catalytic efficiency of the as-prepared composites is then investigated for the reduction of p-nitrophenol, taken as the model reaction. The kinetics of the catalytic reduction of p-nitrophenol reveal that the AuNR-MoS2 QDs composite demonstrates the highest catalytic efficiency, having a rate constant of 0.06 min–1, compared to the AuNS-MoS2 QDs composite, AuNR, and AuNS, having a rate constant of 0.023, 0.021, and 0.008 min–1, respectively. The possible mechanism is also discussed in the paper. Finite difference time domain (FDTD) simulation was carried out to simulate the electric field intensity of the AuNR-MoS2 QDs composite, AuNS-MoS2 QDs composite, AuNR, and AuNS. It is observed that, in general, the electric field intensity increases for the AuNR-MoS2 QDs and AuNS-MoS2 QDs composites when compared with only AuNR and AuNS. Therefore, this study emphasizes understanding the structural role of AuNR-MoS2 QDs and AuNS-MoS2 QDs composites, which is paramount in evaluating the catalytic efficiencies as demonstrated in the reduction of aromatic nitro compounds.

MoS2 quantum dots based on lipid drug delivery system for combined therapy against Alzheimer's disease

Pathological pathways of Alzheimer's disease (AD) are criss-crossed, various pathological factors are dynamically correlated and relatively independent, which makes the single-target drug therapy less effective. Therefore, rational use of multiple therapeutic strategies for accurate inhibition of multiple pathological targets are effective to enhance the efficacy of AD therapy. The combination of drug loading and the excellent photothermal conversion property of nanocomposites is highly innovative to combat the two prominent pathological factors of Alzheimer's disease, oxidative stress and amyloid-β-(1–42) (Aβ1-42) deposition caused by reactive oxygen species (ROS) imbalance. Molybdenum disulfide quantum dots (MoS2 QDs) were selected as carriers and functionalized with lipids (MoS2 QDs/lipid) to improve their dispersibility in water, while effectively escaping immune clearance, improving the efficiency of multi-target applications and targeting advantages. The loading of curcumin (MoS2 QDs/lipid-Cur) not only overcomes the disadvantages of poor water solubility and low bioavailability of the drug, but also achieves the function of sustained release and long-term effect. MoS2 QDs/lipid-Cur showed excellent performance in the two therapeutic targets of anti-Aβ1-42 deposition and elimination of ROS in the early stage, and also obtained consistent excellent results in cell experiments. The drug-loaded combined with NIR treatment group significantly reduced Aβ1-42 mediated neurotoxicity. The in vivo photothermal experiment showed that NIR irradiation in the mouse brain can effectively open the blood-brain barrier (BBB) and increase the permeability of the material to the BBB. At the same time, NIR irradiation enriched drug-loaded material in the mouse brain, resulting in a significant increase in the temperature difference between the mice brains. MoS2 QDs/lipid-Cur is an excellent nanocomposite that integrates multiple functions and can be used for multi-target therapy.

Rapid and ratiometric fluorescent detection of hypochlorite by glutathione functionalized molybdenum disulfide quantum dots

We proposed a rapid and ratiometric fluorescent detection method for hypochlorite by glutathione functionalized molybdenum disulfide quantum dots (G-MoS2 QDs). The G-MoS2 QDs were obtained through a hydrothermal method and the maximum fluorescence intensity was obtained at 430 nm under excitation of 360 nm. The fluorescence of G-MoS2 QDs at 430 nm can be weakened by curcumin through the inner filter effect, meanwhile the fluorescence of curcumin at 540 nm appeared. Hypochlorite can fast oxidize curcumin and weaken the inner filter effect, thus the fluorescence of curcumin at 540 nm decreased and the fluorescence of G-MoS2 QDs at 430 nm increased. This process takes only 30 s at room temperature. This is the rationale behind our rapid ratiometric fluorescent detection model for hypochlorite. Two linear detection ranges for hypochlorite are obtained with concentration from 1 to 20 μM and 20 to 30 μM, the limit of detection (LOD) was 11.5 nM. The standard spike recovery tests on milk and tap water samples showed satisfactory results, which extended the application of G-MoS2 QDs in the field of ratiometric fluorescence detection assays.

Peptide functionalized actively targeted MoS2 nanospheres for fluorescence imaging-guided controllable pH-responsive drug delivery and collaborative chemo/photodynamic therapy

The combination of imaging and different therapeutic strategies into one single nanoplatform often demonstrates improved efficacy over monotherapy in cancer treatments. Herein, a multifunctional nanoplatform (labelled as MPRD) based on molybdenum disulfide quantum dots (MoS2 QDs) is developed to achieve enhanced antitumor efficiency by integrating fluorescence imaging, tumor-targeting and synergistic chemo/photodynamic therapy (PDT) into one system. First, polyethylene glycol (PEG)ylated MoS2 QDs (MP) with desirable stability are synthesized via a hydrothermal process using MoS2 QDs and carboxyamino-terminated oligomeric PEG as raw materials. Then, MP were conjugated with arginine-glycine-aspartic acid (RGD) peptide via amidation to form a novel nanocarrier (MPR), which possesses strong blue fluorescence, good biocompatibility and ανβ3 receptor-mediated targeting ability. More importantly, MPR generated reactive oxygen species under 808 nm laser activation to realize targeted antitumor PDT. Further doxorubicin (DOX) was loaded onto MPR, which endows MPRD with localized chemotherapy and pH-responsive drug release. The MPRD exhibits improved chemotherapy performance on HepG2 cells (overexpressing integrin ανβ3) owing to enhanced cellular uptake mediated by ανβ3 receptor and effective drug release triggered by intracellular pH. Notably, MPRD with efficient tumor targeting ability and high chemo/PDT efficacy under NIR laser irradiation is capable of inhibiting HepG2 tumor cell growth both in vitro and in vivo, which is significantly superior to each individual therapy. These findings demonstrate that MPRD holds great potential in effective cancer therapy.

A heterostructural MoS2QDs@UiO-66 nanocomposite for the highly efficient photocatalytic degradation of methylene blue under visible light and simulated sunlight.

The development of recyclable photocatalysts with high activity and stability has piqued the interest of researchers in the field of wastewater treatment. In this study, an ultrasonic probe approach was used to immerse a sequence of heterojunctions formed by metal-organic frameworks (UiO-66) and different amounts of molybdenum disulfide quantum dots (MoS2QDs), resulting in a highly recyclable MoS2QDs@UiO-66 photocatalyst. Multiple advanced techniques, such as XPS, XRD, TEM, XRF, and UV-vis spectrophotometry, were used to characterize and confirm the successful preparation of UIO-66 impregnated with MoS2QDs. The results indicated that the best heterostructure catalyst exhibited superior efficiency in the photocatalytic degradation of methylene blue (MB) in water, achieving approximately 99% removal within 30 minutes under simulated sunlight, while approximately 97% removal under visible light. The outstanding photocatalytic performance is predominantly attributed to the photoinduced separation of carriers in this heterostructure system. This study proposes a unique, simple, and low-cost method for improving the degradation performance of organic contaminants in water.

Study on One-Step Hydrothermal Preparation and Optical Properties of Molybdenum Disulfide Quantum Dots

Study on One-Step Hydrothermal Preparation and Optical Properties of Molybdenum Disulfide Quantum Dots

In-Situ Generation of Nitrogen-Doped MoS2 Quantum Dots Using Laser Ablation in Cryogenic Medium for Hydrogen Evolution Reaction

Here, nitrogen doped molybdenum disulfide quantum dots (N-MoS2 QDs) are fabricated by making use of the pulsed laser ablation (PLA) process in liquid nitrogen (LN2) as a dopant agent. In fact, LN2 contributes the rapid condensation of the plasma plume to form MoS2 QDs, optimizing the conditions for the synthesis of N-doped MoS2 with p-type property. The structural/optical features of the synthesized products are studied using transmission electron microscopy (TEM), absorption spectroscopy, photoluminescence (PL) spectroscopy techniques, and X-ray photoelectron spectroscopy (XPS). The TEM image shows the creation of MoS2 QDs with 5.5 nm average size. UV-vis and PL spectroscopy confirm the formation of N-MoS2 QDs according to the dominant peaks. The Tuck plot gives a direct band-gap of 4.34 eV for MoS2 QDs. Furthermore, XPS spectroscopy reveals Mo-N bonding, indicating nitrogen doping as evidence of p-type MoS2 QDs. Thus, PLA provides a single-stage way to the clean and green synthesis of the MoS2 QDs suspension without a need for high vacuum devices and additional chemical components. Regarding the pristine MoS2, the N-MoS2 QDs benefit from a low overpotential of −0.35 V at −10 mA/cm2 per µg alongside a low Tafel slope of 300 mV/dec. Subsequently, the lower Rct value of N-MoS2 QDs verifies the enhancement of the charge transfer kinetics mainly due to the elevated electronic conductivity. Furthermore, the quasi-rectangular cyclic voltammetry (CV) as well as the larger current window demonstrate a notable electrocatalytic activity. The former is based on the enhanced active sites in favor of N-MoS2 QDs against other samples of interest. Thereby, it is discovered that the N-doped MoS2 QD acts as an effective catalyst to notably improve the performance of the hydrogen evolution reaction (HER).

Surface engineering of phase controlled defective 1 T-MoS2 QDs@g-C3Nx material for significantly enhanced hydrogen evolution under visible-light irradiation

Design and construction of non-precious metal photocatalysts are necessary to achieve excellent hydrogen evolution reaction (HER) performance and good stability in photocatalytic water splitting systems. Herein, the phase control and defect engineering are applied to fabricate metallic 1 T-phase molybdenum disulfide quantum dots (1 T-MoS2 QDs) decorated 2D g-C3Nx nanosheets with the feature of nitrogen vacancies (denoted as 1 T-MoS2 QDs@g-C3Nx) for photocatalytic HER. The introduction of N defects facilitates to design electronic and energy band structures of g-C3N4. MoS2 QDs is beneficial to improve the charge carrier transport performances in the composite system. And the synergistic effect of phase control and defect engineering can optimize the reaction dynamics of photocatalytic HER. The resultant 1 T-MoS2 QDs@g-C3Nx (15 wt%) shows excellent properties for photocatalytic H2 evolution, with highest H2 generation rate reaching 4.08 mmol g-1h−1. Significantly, the superior H2 production performance of 1 T-MoS2 QDs@g-C3Nx (15 wt%) are achieved, outperforming the benchmark photocatalyst Pt-loading g-C3Nx (2.69 mmol g-1h−1). In addition, 1 T-MoS2 QDs@g-C3Nx (15 wt%) also exhibits high and stable cycling and durability with no significant decay of photocatalytic H2 evolution under continuous 25 h of visible light irradiation (λ > 420 nm). Meanwhile, the possible HER mechanism is explained based on the electronic and energy band structures effects of the g-C3Nx and the 1 T-MoS2 QDs cocatalyst. This work presents an efficient strategy for tuning the optical properties of nitrogen-based photocatalyst to enhance solar energy capture and conversion.

3-Aminophenylboronic acid-functionalized molybdenum disulfide quantum dots for fluorescent determination of hypochlorite.

A simple method is reported for hypochlorite determination based on fluorescence 3-aminophenylboronic acid-functionalized molybdenum disulfide quantum dots (B-MoS2 QDs). B-MoS2 QDs with strong fluorescence at 380nm have been successfully synthesized by the amidation reaction between APBA and hydrothermal MoS2 QDs. Hypochlorite sensing was proposed utilizing the fluorescent quenching effect of 3,3',5,5'-tetramethylbenzidine dihydrochloride (TMB) on B-MoS2 QDs and the fast redox reaction between hypochlorite and TMB. The fluorescent quenching effect of TMB to B-MoS2 QDs was proved to be caused by static dynamic quenching and inner filter effect. A good linear relationship was obtained in the hypochlorite concentration range from 1 to 20μM, and the limit of detection (LOD) was 36.8nM. The proposed fluorescent detection assay was simple and fast, taking only 5min at room temperature. Satisfactory results were obtained in the standard spike recovery tests on tap water and milk samples, which indicate high potential in constructing fluorescent bio-detection assays.

Synchronized wet-chemical development of 2-dimensional MoS2 and g-C3N4/MoS2 QDs nanocomposite as efficient photocatalysts for detoxification of aqueous dye solutions

The photocatalytic performance of graphitic carbon nitride (g-C3N4) is improved by the introduction of molybdenum disulfide (MoS2) quantum dots (QDs), aiming the enhanced visible light absorbance in resultant 2-dimensional g-C3N4/MoS2, termed as GCN/MoS2 hereafter. A novel synthetic approach i.e., pseudo-successive ionic layer adsorption and reaction (p-SILAR) was employed to deposit MoS2 QDs on g-C3N4 and to salvage 2-dimensional MoS2 concomitantly. The results of the photocatalytic activity affirm that GCN/MoS2 worked as a better photocatalyst than the pure g-C3N4, while salvaged MoS2 also showed reasonable degradation of Rhodamine-B (RhB) dye. The average pore size (measured with BET analysis) of GCN/MoS2 was reduced to 31.91 nm from 33.11 nm (for g-C3N4), indicating effectual nanoscale deposition of MoS2 which resulted in a decrease in the overall bandgap alignment of the composite from 2.8 eV to 2.2 eV. In-depth material characterization and photocatalytic analysis was carried out to affirm that p-SILAR serves as a suitable synthesis route for the development of GCN/MoS2 nanocomposite as well as salvaged MoS2.

Directional Formation of Conductive Filaments for a Reliable Organic-Based Artificial Synapse by Doping Molybdenum Disulfide Quantum Dots into a Polymer Matrix.

The conductive filament (CF) model, as an important means to realize synaptic functions, has received extensive attention and has been the subject of intense research. However, the random and uncontrollable growth of CFs seriously affects the performances of such devices. In this work, we prepared a neural synaptic device based on polyvinyl pyrrolidone-molybdenum disulfide quantum dot (MoS2 QD) nanocomposites. The doping with MoS2 QDs was found to control the growth mode of Ag CFs by providing active centers for the formation of Ag clusters, thus reducing the uncertainty surrounding the growth of Ag CFs. As a result, the device, with a low power consumption of 32.8 pJ/event, could be used to emulate a variety of synaptic functions, including long-term potentiation (LTP), long-term depression (LTD), paired-pulse facilitation, post-tetanic potentiation, short-term memory to long-term memory conversion, and "learning experience" behavior. After having undergone consecutive stimulation with different numbers of pulses, the device stably realized a "multi-level LTP to LTD conversion" function. Moreover, the synaptic characteristics of the device experienced no degradation due to mechanical stress. Finally, the simulation result based on the synaptic characteristics of our devices achieved a high recognition accuracy of 91.77% in learning and inference tests and showed clear digital classification results.

One-Step Hydrothermal Synthesis of Highly Fluorescent MoS2 Quantum Dots for Lead Ion Detection in Aqueous Solutions.

Lead ions in water are harmful to human health and ecosystems because of their high toxicity and nondegradability. It is important to explore effective fluorescence probes for Pb2+ detection. In this work, surface-functionalized molybdenum disulfide quantum dots (MoS2 QDs) were prepared using a hydrothermal method, and ammonium tetrathiomolybdate and glutathione were used as precursors. The photoluminescence quantum yield of MoS2 QDs can be improved to 20.4%, which is higher than that for MoS2 QDs reported in current research. The as-prepared MoS2 QDs demonstrate high selectivity and sensitivity for Pb2+ ions, and the limit of detection is 0.056 μM. The photoluminescence decay dynamics for MoS2 QDs in the presence of Pb2+ ions in different concentrations indicate that the fluorescence quenching originated from nonradiative electron transfer from excited MoS2 QDs to the Pb2+ ion. The prepared MoS2 QDs have great prospect and are expected to become a good method for lead ion detection.

Suppressing Non-Radiative Relaxation through Single-Atom Metal Modification for Enhanced Fluorescence Efficiency in Molybdenum Disulfide Quantum Dots.

To enhance the fluorescence efficiency of semiconductor nanocrystal quantum dots (QDs), strategies via enhancing photo-absorption and eliminating non-radiative relaxation have been proposed. In this study, we demonstrate that fluorescence efficiency of molybdenum disulfide quantum dots (MoS2 QDs) can be enhanced by single-atom metal (Au, Ag, Pt, Cu) modification. Four-fold enhancement of the fluorescence emission of MoS2 QDs is observed with single-atom Au modification. The underlying mechanism is ascribed to the passivation of non-radiative surface states owing to the new defect energy level of Au in the forbidden band that can trap excess electrons in n-type MoS2 , increasing the recombination probability of conduction band electrons with valence band holes of MoS2 . Our results open an avenue for enhancing the fluorescence efficiency of QDs via the modification of atomically dispersed metals, and extend their scopes and potentials in a fundamental way for economic efficiency and stability of single-atom metals.

Suppressing Non‐Radiative Relaxation through Single‐Atom Metal Modification for Enhanced Fluorescence Efficiency in Molybdenum Disulfide Quantum Dots

AbstractTo enhance the fluorescence efficiency of semiconductor nanocrystal quantum dots (QDs), strategies via enhancing photo‐absorption and eliminating non‐radiative relaxation have been proposed. In this study, we demonstrate that fluorescence efficiency of molybdenum disulfide quantum dots (MoS2 QDs) can be enhanced by single‐atom metal (Au, Ag, Pt, Cu) modification. Four‐fold enhancement of the fluorescence emission of MoS2 QDs is observed with single‐atom Au modification. The underlying mechanism is ascribed to the passivation of non‐radiative surface states owing to the new defect energy level of Au in the forbidden band that can trap excess electrons in n‐type MoS2, increasing the recombination probability of conduction band electrons with valence band holes of MoS2. Our results open an avenue for enhancing the fluorescence efficiency of QDs via the modification of atomically dispersed metals, and extend their scopes and potentials in a fundamental way for economic efficiency and stability of single‐atom metals.

Constructing combinational and sequential logic devices through an intelligent electrocatalytic interface with immobilized MoS2 quantum dots and enzymes

Stable molybdenum disulfide quantum dots (MoS2 QDs) were synthesized using a simple method and embedded into chitosan (Chit) films with glucose oxidase (GOD) on the surface of a polyaniline (PANI) pre-electrodeposited ITO electrode, designated as Chit-MoS2-GOD/PANI. At the prepared film electrode, the fluorescence property of MoS2 QDs as well as the catalytic properties of MoS2 QDs and GOD were well maintained and could be reversibly regulated by external stimuli, such as pH, potential, and the concentrations of glucose and ascorbic acid (AA) in the solution. By controlling the redox state of PANI with an externally applied voltage, the color of the film electrode switched between violet blue and nearly transparent, simultaneously quenching/dequenching the fluorescence signals from MoS2 QDs through Fӧster resonance energy transfer (FRET). The electrocatalytic signals toward hydrogen peroxide (H2O2), a product formed by biocatalysis between glucose and GOD, could be tuned through the catalytic capacity of MoS2 QDs in the films. Thus, an intelligent platform was built based on the film electrode with pH, potential, glucose and AA as inputs and UV–vis extinction (E), photoluminescent intensity (PL), and amperometric current (I) as outputs. Combinational logic operations such as a 4-input/5-output logic network and sequential logic operations such as a keypad lock and a reprogrammable delay/data (D) flip flop was first simulated in a biocomputing system with the film-modified electrode. This work demonstrated the construction of a multiple stimulus-responsive system with dual-functional nanomaterials and provided a new approach for sequential logic operations for further applications in the information storage.

Selective and Sensitive Electrochemical Sensor for Aflatoxin M1 with a Molybdenum Disulfide Quantum Dot/Metal-Organic Framework Nanocomposite.

Aflatoxins are the hepatotoxic secondary metabolites which are highly carcinogenic and known to cause several adverse effects on human health. The present study reports a simple, sensitive, and novel electrochemical sensor for aflatoxin M1 (AFM1). The sensor has been fabricated by modifying the screen-printed carbon electrodes with a functional nanocomposite of molybdenum disulfide (MoS2) quantum dots (QDs) and a zirconium-based metal–organic framework (MOF), that is, UiO-66-NH2. The MoS2/UiO-66-modified electrodes were decorated with the AFM1-specific monoclonal antibodies and then investigated for the electrochemical detection of AFM1. Based on the electrochemical impedance spectroscopy analysis, it was possible to detect AFM1 in the concentration range of 0.2–10 ng mL–1 with a limit of detection of 0.06 ng mL–1. The realization of an excellent sensing performance can be attributed to the electroactivity of MoS2 QDs and the large surface to volume area achieved by the addition of the MOF. The presence of UiO-66-NH2 is also useful to attain readily available amine functionality for the robust interfacing of antibodies. The performance of the developed sensor has also been validated by detecting AFM1 in the spiked milk samples.

A MoS2QDs/chitin nanofiber composite for improved antibacterial and food packaging

Chitin nanofiber has potential application as antibacterial nanocomposite material because of its inherent biocompatibility, biological activity, amino containing macromolecular structure and nano-size effect. Molybdenum disulfide quantum dots (MoS2QDs) were uniformly bonded on partially deacetylated chitin nanofibers (DEChNs) by hydrothermal reactions. The antibacterial properties of MoS2QDs/DEChN against Escherichia coli were detected under different conditions. When the antibacterial agent was fixed at 200 μg/mL, the survival rates of bacteria were 2.77% (pH = 4), 5.58% (pH = 5) and 7.83% (pH = 6), which were lower than those in the DEChN groups. Unlike DEChN, which only had excellent antibacterial activity under acidic conditions (pH < 5), the combination of DEChN and MoS2QDs had antibacterial activity close to neutral conditions, with a bacteriostatic rate > 90%. When TEMPO-oxidized cellulose nanofibers (TOCN) were applied for the preparation of MoS2QDs/TOCN, they did not show obvious antibacterial ability, which proved the positive role of DEChN and its amino groups. The MoS2QDs/DEChN assembled film could be applied to preserve meat by delaying spoilage. The current study might inspire new ideas for designing food packaging based on the prepared MoS2QDs/DEChN films.

MoS2 QDs-nanoparticle-engineered based hydrophobic filter for high performance water-oil separation

• A novel hydrophobic AC/MoS2 QDs/SSM filter for separation oil–water emulsion. • Preparation by economical materials, simple and one step hydrothermal method. • High selectivity, high flux and high recyclability. The demand for the development of inexpensive and effective approaches for the oil–water separation is increasing due to the global concern in oil industries. In this study, we synthesized nano porous activated carbon (AC)/ Molybdenum disulfide (MoS2) quantum dots (QDs) stainless still mesh (SSM) as a hydrophobic and oleophilic nano filter by hydrothermal method in one step in 200 °C for 12 h, which was characterized by various XRD, FTIR, SEM/Map, TEM, BET-BJH, CV, AFM, DLS and PL techniques. The results showed that the solvent type was also effective in the amount of its separation from oil. Further, the effect of water-to-solvent ratio and pH was investigated. Based on the results of petrol with a water-to-solvent ratio of 20/20 at pH = 7 and at a time of 10 s, 99.99% was separated by AC/MoS2 QDs/SSM. The results showed that repeatability cycle of the AC/MoS2 QDs/SSM was 23 times and its duration to 30 s. The results of kinetic studies revealed that the Pseudo second order kinetic model was in good agreement with the experimental data. This novel filter demonstrated an excellent separation with high selectivity, good flux > 6000 L/m 2 h and high repeatability with great durability from low cost materials and simple method that was appropriate for treating stratified water–oil and water in oil emulsion without using demulsifier.