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A free-standing palladium/reduced graphene oxide paper (Pd/rGOP) based on one-pot co-reduction was prepared. The as-prepared Pd/rGOPs contain evenly distributed Pd particles interposing between the rGOP layers. The structure and composition of Pd/rGOP were characterized by SEM, EDX, XRD and Raman spectra. We investigated the glucose sensing performance of Pd/rGOP by chronoamperometry, the sensitivity reach as high as 6.70 µA mM−1 cm−2 with the linear range between 0.5 mM and 8 mM. The sensor also exhibits a good anti-interference ability and detection selectivity toward the interference. The proposed sensor has great potential to become a reliable tool in point-of-care medical devices.

Paper-based supercapacitors have attracted more and more attention for high electrochemical performance. However, most of them adopt sandwiched structure. Here, we prepared planar polypyrrole (PPy) coated paper-based supercapacitors by applying simple laser carving assisted method. The planar device showed a significant performance improvement (13.9 mF/cm2) compared to the sandwiched device (12.3 mF/cm2). In addition, by adjusting the polymerization time of pyrrole, the device capacity can be further increased to 87.4 mF/cm2. We firmly believed that the laser carving assisted method has a significant role in promoting the development of flexible planar electronic devices.

Effect of ferric chloride concentration on micro-nano structure surface and superhydrophobic property of filter paper was investigated by adsorption and simple immersion process. The results showed that the concentration of ferric chloride solution had great impact on the superhydrophobic property of filter paper. When the concentration was 0 mol/L, filter paper presented hydrophilicity. When the concentration was bigger than 0 mol/L, it exhibited hydrophobicity. The modified filter paper’s surface displayed advancing contact angels of 167 ± 2°, which was attributed to its’ formed micro/nano structure. This may contribute to the development in production applications.

In order to achieve light and flexible gas sensor, we fabricated a uniform carbon nanotube paper made by multi-walled carbon nanotube and employed it as a sensing part. Referring to the transient behavior, it was clarified that the sensor response followed Langmuir isotherm, similar to the previous results prepared on a glass substrate. A repetition characteristics was quite stable and sensitivity was higher than previous one. Thus, it opens prospects for application, but it is unclear why the sensitivity is high despite the increased thickness.

Graphical abstract, Highlights • Antivirals against SARS-CoV-2 are needed. • The papain-like protease represents an important target for antivirals. • We investigated tropane alkaloids from Schizanthus porrigens. • By molecular docking and MS simulations we identified two leads. • Shizanthine Z has favorable ADME properties and can be considered a lead., This paper presents identification of potential inhibitors of SARS-CoV-2 papain-like protease from tropane alkaloids from Schizanthus porrigens, using molecular docking method. Binding affinities were compared with those obtained with Lopinavir as a SARS-CoV-2 papain-like protease inhibitor. Overall, our findings indicate that Schizanthine Z binds to the SARS-CoV-2 papain-like protease with relatively high affinity and favorable ADME properties. Therefore, Schizanthine Z may represent an appropriate compound for further evaluation in antiviral assays.

Graphical abstract, Highlights • Structure parameters and electronic properties of graphene with kagome lattice structure is calculated. • Various XC and dispersion correction methods are used and similar results are obtained. • Pristine graphene with kagome lattice structure shows very small magnetic properties. • A kagome flat-band structure is observed near the EF. • High DOS at flat-band is mostly consisting of pz orbital and also dxz and dyz orbital contributions., In this paper, the electronic properties of a carbon allotrope, graphene with a kagome lattice structure, are investigated. Spin-polarized density functional theory (DFT) calculations with Grimme dispersion corrections were done. Bond lengths, electronic band structure, and projected density of states were calculated. Electronic band structure calculations show kagome flat-band formation with higher d-orbital contributed bonding behavior than the pristine graphene structure. The structural parameters and electronic band results of this 2D carbon allotrope show wider possible usage in many applications from desalination membranes to possible high-temperature superconductors.

The practical application of superhydrophobic coatings on glass is usually restricted by their poor wear resistance due to the insufficient adhesion. A double-silica-layered structure was proposed to reinforce the coating adhesion on glass substrate. The wettability, surface morphologies, and chemical composition were investigated by water contact angle measurement, scanning electron microscopy (SEM), and fourier transformed infrared (FTIR) spectroscopy. The prepared superhydrophobic coating displays a good wear-resistance by emery paper and sand abrasion, which also has excellent thermal stability and UV resistance. This strategy shows a bright future for durable superhydrophobic coating on glass.

Well-developed mesoporous plant-based activated carbon fibers (ACFs) with paper structure were prepared from plant pulp fibers (cotton, sisal hemp, manila hemp, softwood and bleached softwood) using phosphoric acid activation at 450 °C. The structure and performance of ACFs were studied. Results show that ACFs exhibit high mesoporous rate of 72.8%-82.7%, large specific surface area of 1688–1825 m2/g and average pore size of 2.53–3.31 nm. ACFs show relatively high methylene blue (MB) adsorption capacity with 367.5–490.9 mg/g. SHP-ACFs have the largest MB adsorption capacity, the adsorption equilibrium data follows the Langmuir model and the kinetic data could be described by the pseudo-second-order model.

It is firmly established that contemporary building materials and indoor furnishings are associated with elevated concentrations of formaldehyde in indoor air, representing a hazard to human health. To mitigate this issue, formaldehyde and other pollutants in indoor air are removed via air conditioning systems fitted with appropriate filters. Based on positive results from earlier, relevant research, this study investigates the use of air conditioning filters treated with chitosan as potential eco-friendly absorbents for removal of formaldehyde, a significant indoor air pollutant. The filter is sprayed with different dosages of chitosan, in accordance with our previous work [8]. Removal rate and adsorption of formaldehyde are calculated for the health risk assessment. After twenty-four hours testing, the results showed the averaged concentration of formaldehyde is 1.146 ppm, 0.714 ppm, and 0.084 ppm with chitosan dosage of 2.6 mg m−2, 5.3 mg m−2, 8.0 mg m−2, respectively. The averaged reduction of formaldehyde concentration is 64.9%, 80.0%, and 96.0%; the averaged absorption of chitosan on formaldehyde is 0.167 mg, 0.204 mg and 0.271 mg for chitosan dosage of 2.6 mg m−2, 5.3 mg m−2, 8.0 mg m−2, respectively. The risk characterization figures without spaying chitosan are 2.94, 2.65 and 7.07 times higher when compared with the same figures associated with filters treated with 2.6 mg m−2, 5.3 mg m−2, and 8.0 mg m−2 of chitosan. This study finds that chitosan has strong potential as a commercial adsorbent. Increasing the amount of chitosan applied to the filter substrate improves the efficacy of the absorbent and further reduces the indoor formaldehyde concentration and the associated carcinogenic risk.

Graphical abstract, One of the promising drug targets against COVID-19 is an RNA-dependent RNA polymerase (RdRp) of SARS-CoV-2. The tertiary structures of the SARS-CoV-2 and SARS-CoV RdRps are almost the same. However, the RNA-synthesizing activity of the SARS-CoV RdRp is higher than that of the SARS-CoV-2 RdRp. We performed molecular dynamics simulations and found differences in their dynamic properties. In the SARS-CoV RdRp, motifs A–G, which form the active site, are up to 63% closer to each other. We also observed cooperative domain motion in the SARS-CoV RdRp. Such dynamic differences may cause the activity differences between the two RdRps.

Graphical abstract, In this study, density functional theory (DFT) and docking calculations were systematically performed to study the non-competitive interaction between Hydroxychloroquine (HCQ) and azithromycin (AZTH). The calculated changes in Gibbs free energy and enthalpy (at 310 K) were positive, indicating the non-spontaneous formation of HCQ-AZTH specifically in water media. Docking calculation confirmed the obtained DFT result as evident from the different binding sites of both drugs to the SARS-CoV-2 main protease and human angiotensin-converting enzyme 2 (ACE2) proteins. The HCQ-AZTH structure revealed enhanced electrochemical properties, suggesting the synergy between HCQ and AZTH without affecting their therapeutic efficacy against SARS-CoV-2.

Southeastern Anatolia Region of Turkey/Sirnak asphaltites centers are located in and around large reserves in coal mines. Due to the high ash and sulfur content of asphaltite coal, it is important to use it by cleaning with enrichment methods, in terms of solving environmental problems and increasing energy quality. In this study; the main characteristics (chemical analysis, ICP-OES, XRD, SEM analysis) of the asphaltite samples taken from the Avgamasya quarry operating in the center of Sirnak province were determined after the crushing and grinding processes. Later, the asphaltite coal sample was subjected to the flotation enrichment method, which is widely used in fine particle size coal enrichment methods. In the flotation method, the effects of kerosene, fuel oil, and aerophine3418A reagents in different amounts were investigated. Accordingly, the best ash results in the A1(50 g/t kerosene + 0.1 g/t MIBC) experiment; were obtained by adding 50 g/t kerosene reagent and the ash content was determined as 30.80% with an ash content reduction from 46.08% to 33.16%. Best result for reducing the sulfur ratio; in the B2(100 g/t fuel oil + 0.1 g/t MIBC) experiment, it was determined by the addition of 100 g/t fuel oil reagent. Here, the total sulfur content was reduced from 6.46% to 5.71% with a sulfur content reduction of 11.61%.

Graphene and graphite are of great interest in materials science. Using chemical vapor deposition at various CH4:H2 ratios, we synthesized materials with graphene-laminated architectures, ranging from graphene to graphite. A lower proportion of CH4 and lower synthesis temperature produced fewer graphene layers. The transparent properties changed from transparent to semi-transparent, black, and silver as the number of graphene layers was increased. The sheet electrical resistivity ranged from 106 to 0.2 Ω □−1, and the smaller resistivity was nearly equaled as the values of highly orientated pyrolytic graphite and glassy carbon. The graphene-laminated materials featured a wide range of transmittance, reflectance, and electrical conductance properties.

Chemical etching on copper surface is essential as a pre-treatment for single-layer graphene growth by chemical vapor deposition (CVD). Here, we investigated the effect of chemical etching treatment on copper foils for single-layer graphene CVD growth. The chemical etching conditions, such as the type of chemical etchants and the treatment time, were found to strongly influence the graphene domain size. Moreover, a drastic change in the layer structure of graphene sheets, which was attributed to the surface morphology of the etched copper foil, was confirmed by graphene transmittance and Raman mapping measurements.

Ambient plasma is applied to graphite oxide electrodes directly to improve electrochemical properties for supercapacitor applications. Surface morphology of the electrodes after the plasma treatment changes dramatically and amount of oxygen reduced significantly, demonstrating a reduction effect on the graphite oxide electrode by the ambient plasma. Equivalent series resistance of the electrode also reduced from 108 Ω to 84 Ω after the plasma treatment. Corresponding specific capacitance, therefore, increases from 0.45 F cm −2 to 0.85 F cm −2 , proving that the ambient plasma treatment is very efficient, clean, economic, and environment-friendly method to reform the graphite oxide electrodes directly for the supercapacitor applications.

Silica has been used as support material with many photocatalytic materials. In this study, silica polymorphs on graphene and epoxy graphene were studied using Density Functional Theory (DFT) to determine the interfacial and optical properties of the composite material. The powder diffraction patterns and Raman spectra for the silica polymorph structural models as well as graphene and epoxy graphene monoxide were generated using Material Studio (2016), and the GGA in PBE first principle method. The electronic and optical properties as well as work function analysis of the polymorphs with graphene and epoxy graphene monoxide starting molecules together with the layers systems were compared. In Our findings the optical properties of the layers generated were sensitive to the visible light in both epoxy-graphene monoxide and graphene composites.

We propose facile synthesis methods to prepare two three-dimension (3D) multi-porous graphene structures including graphene aerogel and graphene nanowalls. The graphene aerogel was prepared via the hydrothermal reduction and tert -butanol freeze-drying. The graphene nanowalls were prepared by growing the obtained graphene aerogel via a plasma enhanced chemical vapor deposition (PECVD). High specific surface areas of these two structures up to 795 m 2 /g were obtained by BET analyses. The crystallized, multi-porous, and thermal stable features of these two 3D graphene structures were verified via the X-ray diffraction, SEM, Raman spectroscopy and thermal gravity analysis characterizations.

The pure MoS 2 and MoS 2 @reduced graphene oxide were synthesized on commercially available Ti plate by one-step hydrothermal method. The hole microspheres were successfully synthesized. The resulting MoS 2 @reduced graphene oxide electrode on Ti plate exhibited higher catalytic activity than pure MoS 2 electrode on Ti plate for hydrogen evolution reaction. In addition, the excellent cycling stability was also obtained in MoS 2 @reduced graphene oxide electrode on Ti plate. Such enhanced catalytic activity and excellent cycling stability occurred due to the abundance of catalytic edge sites, high specific surface area and the unique synergic effects between the MoS 2 and reduced graphene oxide.

Poly(vinyl alcohol), PVA, polymer was successfully combined with graphene oxide (GO) and thermally reduced graphene oxide (RGO), respectively, to make composites and characterized for supercapacitor applications. PVA-RGO composite shows excellent electrochemical properties compared to PVA-GO composite. The capacitance of 190 Fg −1 is obtained from PVA-RGO composite which is larger than that (13 Fg −1 ) of PVA-GO composite. Electrochemical impedance of PVA-RGO is more than ten times smaller than that of PVA-GO at 20 kHz, demonstrating that PVA-RGO composite has a great advantage for supercapacitor applications compared to PVA, GO, RGO, and PVA-GO composite.

Graphical abstract, SARS-CoV-2 has posed global challenge for healthcare due to COVID-19. The main protease (Mpro) of this virus is considered as a major target for drug development efforts. In this work, we have used virtual screening approach with molecular dynamics simulations to identify high affinity and low molecular weight alternatives of boceprevir, a repurposed drug currently being evaluated against Mpro. Out of 180 compounds screened, two boceprevir analogs (PubChem ID: 57841991 and 58606278) were reported as potential alternatives with comparable predicted protease inhibitor potential and pharmacological properties. Further experimental validation of the reported compounds may contribute to the ongoing investigation of boceprevir.

Graphical abstract, Humans around the globe have been severely affected by SARS-CoV-2 and no treatment has yet been authorized for the treatment of this severe condition brought by COVID-19. Here, an in silico research was executed to elucidate the inhibitory potential of selected thiazolides derivatives against SARS-CoV-2 Protease (Mpro) and Methyltransferase (MTase). Based on the analysis; 4 compounds were discovered to have efficacious and remarkable results against the proteins of the interest. Primarily, results obtained through this study not only allude these compounds as potential inhibitors but also pave the way for in vivo and in vitro validation of these compounds.

Graphical abstract, The COVID-19 pandemic caused by SARS-CoV-2 has resulted in an international health emergency. The SARS-CoV-2 nsp16 is an S-adenosyl-L-methionine (SAM)-dependent methyltransferase, and with its cofactor nsp10, is responsible for RNA cap formation. This study aimed to identify small molecules binding to the SAM-binding site of the nsp10-nsp16 heterodimer for potential inhibition of methyltransferase activity. By screening a library of 300 compounds, 30 compounds were selected based on binding scores, side-effects, and availability. Following more advanced docking, six potential lead compounds were further investigated using molecular dynamics simulations. This revealed the dietary compound oleuropein as a potential methyltransferase inhibitor.

Highlights • The physical origin of interactions of hydroxychloroquin (HCQ) and the key-residues (KR) of the receptor binding domain (RBD) of SARS-CoV-2 in aqueous medium were investigated with the combined MD simulation and ONIOM techniques. • Heterogeneous binding affinities of HCQ and the KRs of RBD were governed by the differential life-time of the hydrogen bonded water network anchoring HCQ and KR. • Intermolecular proton transfer facilitates most favorable Lys417:HCQ complexation. • Off-target bindings of HCQ need to be minimized to prevent the transmission in a more efficient manner., Interactions of hydroxychloroquin (HCQ) with the receptor binding domain (RBD) of SARS-CoV-2 were studied from atomistic simulation and ONIOM techniques. The key-residues of RBD responsible for the human transmission are recognized to be blocked in a heterogeneous manner with the favorable formation of key-residue:HCQ (1:1) complex. Such heterogeneity in binding was identified to be governed by the differential life-time of the hydrogen bonded water network anchoring HCQ and the key-residues. The intermolecular proton transfer facilitates the most favorable Lys417:HCQ complexation. The study demonstrates that off-target bindings of HCQ need to be minimized to efficiently prevent the transmission of SARS-CoV-2.

Graphical abstract, Highlights • Lurasidone and Lurasidone exo inhibit SARS-CoV-2 via ‘one drug multiple targets’ strategy. • MD simulation revealed their strong binding affinity against multiple targets of SARS-CoV-2. • Both the drugs exhibit favourable pharmacokinetic properties as predicted by ADMET parameters. • Their unique multitargeting feature warrants further in-vitro and in-vivo experiments., The emerging paradigm shift from ‘one molecule, one target, for one disease’ towards ‘multi-targeted small molecules’ has paved an ingenious pathway in drug discovery in recent years. We extracted this idea for the investigation of drugs for COVID-19. Perceiving the importance of organosulfur compounds, seventy-six known organosulfur compounds were screened and studied for the interaction with multiple SARS-CoV-2 target proteins by molecular dynamics simulation. Lurasidone and its derivatives displayed substantial binding affinity against five proteins (Mpro, PLpro, Spro, helicase and RdRp). The pharmacokinetics, ADMET properties and target prediction studies performed in this work further potentiates the effectiveness against SARS-CoV-2.

Graphical abstract, Highlights • Prenatal Choline level protects the fetus's developing brain from effects of CoV2. • Choline from many food supplements can protect the fetus from Coronavirus. • Choline is used for treatment of many neurodegenerative diseases like Alzheimer. • Natural Choline may regulate 3CLpro protein’s viral replication., Prenatal COVID infection is one of the worst affected and least attended aspects of the COVID-19 disease. Like other coronaviruses, CoV2 infection is anticipated to affect fetal development by maternal inflammatory response on the fetus and placenta. Studies showed that higher prenatal choline level in mother’s body can safeguard the developing brain of the fetus from the adverse effects of CoV2 infection. Choline is commonly used as food supplement. By virtual screening, molecular docking and molecular dynamics techniques, we have established a strong inhibitory possibility of choline for SARS 3CLpro protease which may provide a lead for prenatal COVID-19 treatment.

Nanohole graphene oxide (NHGO) was obtained in a homogeneous aqueous mixture of graphene oxide (GO) and H 2 O 2 at 120 °C. Supercapacitors were fabricated as the electrode material by using NHGO. A specific capacitance of 240.1 F g −1 was obtained at a current density of 1 A g −1 in 6 m KOH electrolyte and specific capacitance remained 193.6 F g −1 at the current density of 20 A g −1 . This was attributed to reducing the inner space between the double-layers, enhanced ion diffusion and large specific surface area. Supercapacitor prepared with NHGO electrodes also exhibited an excellent cycle stability.

Facile synthesis of graphene–Nb2O5 composite has been reported. Graphene oxide was prepared by the modified Hummer's method. The metal oxide (Nb2O5) was introduced to the graphene to form the composite by the hydrothermal method. The prepared samples were characterized by X-ray diffraction, scanning electron microscopy, high resolution transmission electron microscopy, Fourier transform infrared (FTIR) and thermo gravimetric analysis (TGA). SEM and TEM results revealed that the metal oxide particles are uniformly dispersed on the surface of thin sheets of well-defined multilayered graphene structure. Thermal stability of the graphene metal oxide nanocomposites was also investigated. The CV measurements reveal a significant enhancement in the specific capacitance reaching 321 Fg−1 at a scan rate of 10 mV s−1. With promising electrochemical characteristics, Nb2O5 decorated graphene nanocomposite are explored as potential electrode material for supercapacitor applications.

Microbial fuel cell (MFC) can commendably treat wastewater in anodic chamber with the concurrent production of bioelectricity. If the anodic effluent can be further treated in cathodic chamber through the H2O2 produced in this chamber, it can provide holistic treatment to the wastewater. In this regard, the present investigation focused on the application of Ni and Ni-Pd as cathode catalysts in MFC, which resulted in 2.2 and 2.6 times higher production of H2O2 leading to 15% and 29% higher chemical oxygen demand removal, respectively. Thus, MFCs can be effectively applied as a performant technology for providing comprehensive treatment to wastewater.

Graphical abstract, Highlights • A solution has to be found rapidly against COVD-19. • From a set of 10 compounds of Aloe vera, 3 potential inhibitors of SARS-CoV-2 main protease were identified. • The binding affinity of ligand-protein interactions and the Lipinski’s rule of five based-on ADME analysis were used to confirm the best candidate., SARS-CoV-2 is the pathogen agent of the new corona virus disease that appeared at the end of 2019 in China. There is, currently, no effective treatment against COVID-19. We report in this study a molecular docking study of ten Aloe vera molecules with the main protease (3CLpro) responsible for the replication of coronaviruses. The outcome of their molecular simulation and ADMET properties reveal three potential inhibitors of the enzyme (ligands 6, 1 and 8) with a clear preference of ligand 6 that has the highest binding energy (−7.9 kcal/mol) and fully obeys the Lipinski’s rule of five.

Today world is facing water pollution resulting from various sectors and presenting serious ecological concerns. The reusability of polluted water could be a promising study for the sustainable wastewater management strategy. In this, prepared ZnFe2O4 nano-photocatalyst was employed for photocatalytic degradation of organic dye pollutants namely Acid Red 88 (AR-88), Acid Orange 8 (AO 8) and Malachite Green (MG) under Sun light and UV irradiation. The UV-induced dye degraded wastewater samples were used to examine the green assessment towards the growth of Eleusine coracana (Finger millet) and Vigna unguiculata (Black eyed beans) plant. The results showed excellent plant growth in dye degraded wastewater sample noticed in the period of 3–5 days compared to pure water as control and with retard growth observed in dye solution. Thus, present research reported that the sustainability issues related to photodegradation of contaminated dye solution using prepared nano material was tested and efficiently using treated waste water in growing plants.

Truculent retting-pond wastewater was treated by anaerobic and photo-catalytic process for phenol removal. Up flow anaerobic sludge blanket reactor was operated over a period of 164 days at different pH of 3, 5, 7 and 9; Hydraulic Retention Time (HRT) was fixed from 35 to 20 h. Anaerobic reactor showed COD and phenol removal of 85% and 75% at optimum pH-7 & HRT-25 h. Research Surface Methodology (RSM) and regression quadratic model were used in describing the efficiency of COD removal. Photo-catalytic process was developed by ANOVA. The combined anaerobic and photo-catalytic treatment showed 95% and 93% in COD and phenol removal.

Recently, Chen et al. presented a fascinating paper about the synthesis and mechanochemical transformation of ladderenes. These compounds are sufficiently stable to undergo controlled transformation to polyacetylene if exposed to mechanical load caused, for example, by ultrasound. The present paper adds a closer analysis of the behaviour of the electronic structure under these conditions as well as a study of the photochemical behaviour. The influence of potential side reactions is discussed.

A hybrid plasma-enhanced chemical vapor deposition (PECVD)/sputtering system was developed to prepare iron (Fe)-nitrogen (N)-doped carbon catalysts for oxygen reduction reaction (ORR). This hybrid system combines PECVD effective for the synthesis of nanocarbons with sputtering technique for the doping of metals such as Fe where the amount of the doping can be independently controlled during synthesizing nanocarbons. By using this system, Fe-N-doped carbon catalysts are directly synthesized on carbon papers which have been widely used as a gas diffusion layer in fuel cells. The synthesized catalysts with carbon papers exhibit high ORR activity. This is attributed to Fe-N coordination bonds which are stably formed in the synthesized catalysts.

In this paper, adjusting the electrolyte composition or the use of additives has been shown to obtain different characteristics in lithium ion batteries. By improving the characteristics of one component in the electrolyte, the lithium ion battery electrolyte can be tuned to be suitable for different environments. This paper describes the theoretical research progress on fluoroethylene carbonate as an additive for the electrolyte of lithium ion batteries and also analyzes whether fluorine-containing additives, flame retardants and wetting agents can be used together to improve the performance of lithium ion batteries. Fluoro-containing additives (FEC) can improve the oxidation resistance of the electrolyte on the positive electrode, which can lead to electron transfer before vinyl carbonate (EC) and can also reduce the electrolyte at the negative electrode interface before the solvent, thus, inhibiting any further decomposition of the electrolyte.

A polemic is given regarding several of the calculated numerical values given in the published paper. The authors’ calculated apparent molal volumes for tryptophan and tyrosine dissolved in aqueous-ascorbic acid solutions cannot be obtained from the experimental density data and amino acid molalities given in the published paper. Moreover, the authors’ calculations show tyrosine to have the larger apparent partial molal volume, which is just opposite to what has been reported in the published literature.

Water adsorption effect on a solid surface can change water fluidity and viscosity to leave an impact on engineering processes. However, the water adsorption effect caused by Coulomb interaction (Coulomb adsorption) has seldom been tested. Therefore, this paper designed a narrow slot seepage experiment to study the water adsorption effect on water fluidity under different external electric field along with different ion concentration and hydraulic gradient. The experiment results showed that the dynamic viscosity of water in the slot would be enhanced by the growing electric field strength; the growth of hydraulic gradient was not conductive to Coulomb adsorption; and there was a threshold hydraulic gradient iT (around 26.67 in this paper) that when i > iT, the growth of ion concentration would be conductive to Coulomb adsorption, while it would be adverse to Coulomb adsorption when i

Miniaturization is an important direction of the development of science and technology. With the rapid development of micro electro mechanical system, microfluidic system based on microfabrication system has begun to exist in large numbers in laboratories. Micromixer is the focus of microfluidic system, widely used in biomedicine, materials science, aerospace and other fields of science. Passive micromixer is different from ordinary active micromixer, it does not require the input of external energy, but the design of a three-dimensional junction to control the mixing process. In this paper, we design a structure base on topology optimization method. This structure allows the two solutions to reverse flow and enhance the chaotic convection. This paper takes the circular structure as the original structure, and a series of topological micromixers with circular (TMCx) structures are analyzed by numerical simulation. These structures are TMC, TMC0.25, TMC0.5, TMC0.75, Circular micromixer. We analyze their mixing efficiency and pressure drop under different Reynolds number. By comprehensive comparison, it is concluded that TMC0.75 is the optimal structure. In addition, it is proved that the Circular micromixer in this paper has better performance than the Square wave micromixer in the previous paper.

N-doped carbon hollow microspheres (NCMs) have been prepared by a facile water-assisted chemical vapor deposition (CVD) process using melamine as both the carbon precursor and N-dopant and ferrocene as both the catalyst and carbon precursor. It is shown that the size of the NCMs can be tuned just by changing the annealing temperature of the CVD furnace. The atomic percentage of nitrogen doping in NCMs could be achieved to 7.85% without sacrificing the hollow spherical structure. Probable growth mechanism of NCMs was proposed in this paper. The work reported here may pave a way for designing novel various atom-doped carbon microspheres.

Porphyrin dyes are susceptible to aggregation which may cause lower short-circuit current density affecting its photoelectric conversion efficiency (PCE) in dye-sensitized solar cells. In this paper, we harness the inherent property of metallated porphyrins that it can axially coordinate with compounds containing lone-pair of electrons, such as pyridines, through the back π-bonding. The use of pyridine or bipyridine spacers to suppress aggregation in β -functionalized Zn-tetraphenylporphyrin-based dyes showed improvement of PCEs by 28% and 44% for 4-methylpyridine and 4,4′-bipyridine ligands, respectively. This clearly demonstrates the benefits of the simple but effective method in suppressing dye aggregation thereby increasing its efficiency.

This paper reported a simple hydrothermal method to prepare MoS2 with different surface affinity. By adjusting the reaction time and Mo/S proportion of hydrothermal synthesis, MoS2 powder with a face-to-edge ratio of 1.19 can be obtained on the surface. Interestingly, for the first time, MoS2 with such ratio can function as an intermediary similar to surfactant. It tends to distribute on the interface between water and n-hexane, and further adsorb methylene blue from water to the interface. By this route, it has a great implication for the interaction of incompatible molecules and the interfacial process in future applications.

In this paper, the adsorption of Hydrogen cyanide (HCN) molecules on metal-doped boron nitride nanotube (BNNT) is studied by using density functional theory (DFT) method. Our calculations indicate that the adsorption energy corresponding to this structure increases greatly. In addition, metal doping changes the charge distribution of the BNNT, which results in various hybrid orbitals. The frontier orbital function distribution of this configuration also changes from being uniformly distributed in the tube to being substantially concentrated around the metal atoms and HCN molecules. The results of this series of studies provide new possibilities for HCN sensor research.

In this paper, first-principles molecular dynamics simulations are applied to study the ionic structure and electronic properties of KF-NaF-AlF3 system. The results show that the main forms of complex ion groups are [AlF4]−, [AlF5]2− and [AlF6]3−. With KF concentration increasing, the covalent interaction between Al F ions first increases and then decreases, resulting in the increase of Al F coordination number and then decreases. The calculation results of Raman spectra on [AlF4]−, [AlF5]2− and [AlF6]3− are close to the experimental values, which indicates FPMD is applicable to similar molten salt systems.

Various types of fuel cells as clean and portable power sources show a great attraction, especially direct methanol fuel cells (DMFCs) having high energy density and convenient fuel storage. In this paper, PtNi bimetallic nanoparticles (NPs) supported on the electrochemically reduced porous graphene oxide (ERPGO) was fabricated by one-step electrochemical reduction of the mixture of H2PtCl6, NiSO4 and porous graphene oxide (PGO). The obtained hybrid of PtNi/ERPGO was investigated by using scanning electron microscopy (SEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS). Furthermore, the electrocatalytic activity for methanol oxidation reaction (MOR) was evaluated by electrochemical method. The experimental results have demonstrated that PtNi/ERPGO enhanced electrocatalytic activity, which might be attributed to the bifunctional mechanism and the existence of unique pore structure on the surface of graphene sheets.

The present paper deals with the photophysical and time resolved spectroscopic investigations performed on the pristine short chain dyad, (E)-4-(((9H-fluorene-2-yl)imino)methyl)-N,Ndimethylaniline (NNDMBF) and its nanocomposite forms with CQD or NCQD. The experimental results with dyad-CQD (or NCQD) demonstrate that more than 80% trans structure of the ground state dyad could be protected in the environment of CQD (or NCQD) even on photoexcitation. Formations of elongated trans- conformers show in favor of efficient energy-storage systems. The stability of extended conformation has been hinted to be due to combination of surface coverage and surface trap effects, the later process seems to be the dominating one.

Two-dimensional materials attracted extensive attentions in recent years due to their unique properties and various potential applications. In this paper, based on crystal structure prediction, we acquired two stable 2D monolayers of Boron-Carbon-Phosphide compounds, a honeycomb-like and completely flat monolayer BC2P and a semiconductor-metal transition monolayer BC3P3, and discussed structural, electronic and optical properties of the monolayers. Two monolayers are indirect semiconductors having band gaps of 1.4095 (2.0176) eV and 0.4099 (1.004) eV with GGA-PBE (HSE06) which can be tuned under different tensile strains. The wide and tunable band gap of monolayer BC2P makes it exhibit more advantages in terms of high-frequency-response optoelectronic materials. Furthermore, under a-biaxial tensile strain from 6% to 9%, the monolayer BC3P3 can be transformed from a semiconductor to a metal, indicating it has potential applications in strain-engineering nanodevices.

International audience; In this paper, we investigate the role of structural dynamical effects on reactivity properties of selected Michael acceptors. To this aim, quantum molecular dynamics simulations were performed. Conceptual density functional theory descriptors were then evaluated on selected snapshots, providing statistical indicators suitable to assess the discrepancies between static and dynamical approaches. The implications of these results for building a predictive model correlated to Mayr’s electrophilicity index are then discussed, paving the way towards a more realistic account of experimental results.

This paper proposed a metamaterial with dual-band, wide bandwidth, high quality negative refractive band and quasi-zero refractive band. It consists of a symmetrical double-opening ring and bimetallic wire, and is verified by classical triangle method. The mechanism of dual-band negative refraction is studied, and the analysis of surface current and field distribution is completed. Through the novel test scheme, the free-space measurement of electromagnetic parameters was carried out. The test results are highly matched with the simulation results.

In this paper, we describe a novel nanocomposite structure consisting of CsPbI3 crystals growing on carbon nanofibers by electrospinning and following thermal treatment. Detailed characterization results reveal that these CsPbI3 crystals are single-crystalline with high thermal stability. The resultant composite nanofibers show wide bandgap of 2.71 eV and narrow photoluminescence full-width-at-half maximum (FWHM) of 29 nm, exhibiting fluorescence quenching phenomenon after thermal treatment. These composite nanofibers with a well-defined morphology offers new opportunities for high-performance optoelectronic devices.

In this paper, by employing first principles calculations, a two dimensional global minimum structure of Lithium Sulfide (Li2S) was predicted with a wide direct band gap and an inversed sandwich structure 1T-MoS2. The electronic properties investigations reveal that the predicted Li2S monolayer has a strain tunable direct band gap of 3.20 (4.05 eV) computed by PBE (HSE06) theory. As a wide band gap (WBG) semiconductor that is stable at high temperatures, this monolayer may have many applications in electronics and optoelectronics devices. Furthermore, the presence of a narrow phonon band gap between acoustic and optical modes suggests its application in opto-mechanical resonators.

In this paper, we reported a one-step and facile method to prepare boron carbon oxynitride (BCNO) nanosheet and titanium dioxide (TiO2) loaded BCNO nanocomposites. The BCNO nanosheet not only can widen the absorption range of TiO2 from ultraviolet to visible region, but also increase the photodegradation ability. The TiO2/BCNO nanocomposites have excellent photo-degradation performance on organic dyes. The TiO2-2/BCNO-2 nanocomposite can degrade almost all of methylene blue (MB) and rhodamine B (RhB) during 50 and 300 min under visible light irradiation, respectively. In addition, the photocatalytic mechanism can be explained by the electron transition process between TiO2 and BCNO.