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In this study, Mesosphaerum suaveolens extracts were used for the green fabrication of fluorescent Carbon Quantum Dots (CQDs) by the microwave-assisted method. This study unravels the effect of CQDs on improving the photocatalytic degradation of methylene blue (MB) and Rhodamine B (RhB) dyes followed by the anticancer activity against human breast cancer cells (MDA-MB-231). The bio-fabricated CQDs indicated various characteristics that were analyzed, including phase, structure, functional groups, and binding energies. The CQDs displayed notable photocatalytic performance in the removal of MB (80.73%) and RhB (92.3%) dye, after 200 min of sunlight irradiation. The highest catalytic degradation activity of the CQDs is accredited to their high electron transport at the edges, which is helpful to the efficient separation of electron–hole pairs. Furthermore, the anticancer activity of CQDs was demonstrated against human breast cancer cells (MDA-MB-231). This research suggests that bio-fabricated CQDs act as active photocatalysts and hold promise as a potentially ideal material for mitigating water pollution and exploring anticancer potentials in the future. [ABSTRACT FROM AUTHOR]

Titanium dioxide quantum dots (TiO2-QDs), synthesized using a microwave-assisted method, represent a significant advancement in photocatalysis, particularly in the treatment of environmental pollutants. This study focuses on TiO2- QDs synthesized at 200°C for a duration of 5 minutes, using titanium butoxide as a precursor. Characterization through TEM, XRD, PL, and UV-Vis-DRS analyses revealed uniform quantum dots with an average size of 5.28 nm, a bandgap energy of 3.22 eV, and a crystalline anatase phase, indicative of high photocatalytic activity. Notably, these TiO2-QDs demonstrated exceptional performance in degrading methylene blue (MB) in water, achieving a remarkable treatment efficiency of 97.6% in 120 min, significantly outperforming both conventional titanium dioxide nanoparticles and commercial titanium dioxide materials. The reaction conditions were evaluated based on factors such as catalyst dose, initial MB concentration, and pH. The results indicate that optimal degradation efficiency of MB was achieved at a pH of 7, with a catalyst dose of 0.15 g/L and at a low MB concentration. The efficiency slightly decreased to 94.5% after five reuse cycles, emphasizing its significant reusability and stability. [ABSTRACT FROM AUTHOR]

In this study, mesoporous FAU zeolites with pores in the range of 3–4 nm were successfully synthesized by acid leaching method using several organic acids. Zeolite samples were treated with six organic acids (acetic, oxalic, succinic, adipic, malic, and D-tartaric acid) in microwave-assisted acid leaching to investigate the influence of specific acids on formation of mesostructured zeolite ability to evaluate their influence on mesostructure formation and potential applications. X-ray diffraction (XRD) demonstrated that all synthesized samples retained the initial crystalline structure. The nitrogen physisorption curves indicated that all samples possess mesoporous structures. According to TEM results, the proposed mechanism of the method was due to acid diffusion and corrosion from the external to internal structure leading to the formation of the mesoscale pores. The adsorption capacity was investigated with methylene blue (MB), and the results varied according to the acid used but were generally much higher than untreated zeolite X. These findings suggest that the one-step microwave-assisted acid leaching method holds significant potential for practical applications due to its efficiency and simplicity. [ABSTRACT FROM AUTHOR]

[Display omitted] • The possible growth mechanism of the formation of inorganic–organic CdSe(en) 0.5 is described. • Porous CdSe photoanode developed via a microwave-assisted and hydrothermal method on Cd foil. • The optimized CdSe-6H photoanode shows a photocurrent density of 7.4 mA cm−2 (0 V vs Ag/AgCl) with 274 μmol cm−2/3 h hydrogen gas evolution. • The porous structure effectively enhances the photoelectrochemical properties of CdSe photoanode. In this study, inorganic–organic hybrid CdSe(en) 0.5 nanosheet (NS) was developed on Cd foil via the microwave-assisted (MW) method with different MW irradiation cycles. Furthermore, the photoelectrochemical (PEC) performance of the mother material was improved through a second hydrothermal method with different time variations (3, 6, and 12 h at 160 °C). After the second hydrothermal, organic moieties were removed, and a porous photoanode was obtained. The optimized CdSe-6H photoanode showed a photocurrent density of 7.4 mA cm−2 (0 V vs Ag/AgCl) with 272 μmol cm−2/3h hydrogen gas evolution under one sun illumination. The enhanced PEC performance was attributed to the topotactic transformation, improved light absorbance, enhanced charge separation, and improved surface area. This work offers a rational approach for building inorganic–organic electrodes through the MW method and porous photoanode for PEC hydrogen production. [ABSTRACT FROM AUTHOR]

Spinel nanomaterial of ZnFe2O4 has been successfully synthesised and its high crystallinity is confirmed by x-ray diffraction analysis in the Fd3m space group with crystallite size of around 37.96 nm. The agglomerated nature of the sample is confirmed through SEM analysis and compositional analysis using EDS. The maximum yield of 94.66% biodiesel is obtained at 15 min, 50°C temperature, 6 weight % catalyst, and 6:1 ethanol: oil conditions. The FTIR analysis and ¹H-NMR analysis of waste cooking oil and biodiesel of different yields confirm the different functional groups exist in the sample and the biodiesel. The physio-chemical properties of the biodiesel match well with the literature values. The reusability of the ZnFe2O4 confirms the yield of 80.9% after 3 cycles under the same reaction conditions. [ABSTRACT FROM AUTHOR]

Economical water electrolysis requires highly active non-noble electrocatalysts to overcome the sluggish kinetics of the two half-cell reactions, oxygen evolution reaction, and hydrogen evolution reaction. Although intensive efforts have been committed to achieve a hydrogen economy, the expensive noble metal-based catalysts remain under consideration. Therefore, the engineering of self-supported electrocatalysts prepared using a direct growth strategy on three-dimensional (3D) nickel foam (NF) as a conductive substrate has garnered significant interest. This is due to the large active surface area and 3D porous network offered by these electrocatalysts, which can enhance the synergistic effect between the catalyst and the substrate, as well as improve electrocatalytic performance. Hydrothermal-assisted growth, microwave heating, electrodeposition, and other physical methods (i.e., chemical vapor deposition and plasma treatment) have been applied to NF to fabricate competitive electrocatalysts with low overpotential and high stability. In this review, recent advancements in the development of self-supported electrocatalysts on 3D NF are described. Finally, we provide future perspectives of self-supported electrode platforms in electrochemical water splitting. [ABSTRACT FROM AUTHOR]

Molybdenum disulfide is an effective solid lubricant, but it suffers from oxidation and moisture absorption issues, resulting in insufficient wear resistance and a shortened lifespan. This study introduces an innovative approach, integrating graphitic carbon nitride with molybdenum disulfide via advanced microwave‐assisted synthesis, offering precise control over synthesis parameters. The research assesses the tribological performance, comparing it with conventional hydrothermal synthesis. The study extensively investigates the morphology, microstructure, and tribology of a g‐C3N4/MoS2 nanocomposite created through novel microwave (g‐C3N4/MoS2‐MW) and hydrothermal techniques (g‐C3N4/MoS2‐HT). MoS2 exhibits a flower‐like structure, while graphitic carbon nitride has a layered structure, as confirmed by elemental analysis via energy‐dispersive X‐ray spectroscopy. X‐ray diffraction identifies g‐C3N4 peaks at 13.0° (100) and 27.5° (002) and hexagonal MoS2 peaks at 14° (002), 32.7° (100), 35.8° (102), and 58.3° (110). The Fourier‐transform infrared spectrum reveals peaks at 1237.4 and 808 cm−1 (aromatic and triazine ring breathing modes in g‐C3N4), 1407.1 and 1638.9 cm−1 (C=N and C−C heterocyclic structures), and 3432 cm−1 (vibrations due to −NH and −OH). The coefficients of friction for microwave‐assisted and traditional hydrothermal synthesized nanocomposites are 0.22 and 0.34, respectively. The wear depths are 98 microns and 141 microns, with a wear scar diameter of 2.87 mm for g‐C3N4/MoS2‐MW and 3.45 mm for g‐C3N4/MoS2‐HT, indicating superior lubrication with the microwave‐assisted coating. [ABSTRACT FROM AUTHOR]

In this study, visible-light copper bismuth oxide (CuBi2O4) photocatalyst were synthesized via coprecipitation (CuBi2O4-C) and microwave-assisted methods (CuBi2O4-M). The X-ray powder diffraction (XRD) analysis reveals the presence of pure tetragonal, along with band gaps of 2.9 eV in both samples. The microwave-assisted method produced flower-like CuBi2O4 microspheres, which had a larger BET surface area and demonstrated the highest photocatalytic performance, approximately 83.4 % in the decolorization of malachite green (MG) dye under visible light. Therefore, the research suggested a facile strategy for the fast synthesis of CuBi2O4 microspheres under mild reaction conditions. The use of microwave heat treatment is a faster and more efficient way to photocatalyst materials, while also being cost-effective and energy-saving. [ABSTRACT FROM AUTHOR]

A series of nitrogen-doped photoluminescent carbon dots (N-doped CDs) with a proper quantum yield was prepared through microwave-assisted pyrolysis of citric acid and urea as the carbon and nitrogen sources, respectively. The obtained N-doped CDs were fully characterized by high-resolution transmission electron microscopy, elemental analysis, Fourier transform infrared spectroscopy, and X-ray diffraction pattern. The average size of the synthesized N-doped CDs was determined using high-resolution transmission electron microscopy analysis was approximately 7 nm and the interlayer distance was 0.29 nm, which was consistent with the results obtained by X-ray diffraction. The optical characteristics of the samples were determined by UV-Vis and photoluminescent spectroscopy. The aqueous solution of N-doped CDs showed a multicolor emission wavelength, in the range of 350 to 650 nm, dependent on the nitrogen-doped percentage. With increasing the nitrogen percentage, the emission spectra, depending on the excitation wavelength, have one or two peaks in the green and blue regions, which can be considered in applications such as special bioimaging and related fields. [ABSTRACT FROM AUTHOR]

Mesoporous titania nanoparticles (MTN) were prepared using different surfactants namely anionic (MTN-A), cationic (MTN-C) and nonionic (MTN-NI) surfactants via microwave-assisted method to degrade 2-chlorophenol (2-CP) under visible light irradiation. The catalysts were characterised by XRD, FTIR, UV-Vis DRS, PL, BET, FESEM, TEM and XPS. The mesoporous structures were successfully formed in all catalysts with high surface area. However, the significant difference between the prepared catalysts was the formation of mixed-phase in MTN-A which used sodium dodecyl sulfate (SDS) as anionic surfactant. MTN-A composed of 20% rutile and 80% anatase phase. MTN-A showed remarkable photoactivity due to the abundance of Ti3+ site defects (TSD) and oxygen vacancies (OV) on its TiO2 mixed-phase structures. The synergistic effect between the TSD, OV and TiO2 mixed-phase have improved the electronic band structure, aided the charge migration and reduced the electron–hole recombination rate, thus increasing its photoactivity. Moreover, MTN-A exhibited the best performance with 85% degradation compared to MTN-C, MTN-NI and pretreated commercial TiO2, Degussa P25 (P25) with 77%, 18% and 62% degradation, respectively. MTN-A also displayed as a promising photocatalyst because it could degrade other chlorophenol derivatives. Highlights: Synthesis of MTN using SDS as surfactant generated mixed phase of TiO2 Type of surfactant influence the amount of site defects formation on surface of MTN Mixed phase and site defects of MTN reduced the electron–hole recombination of MTN 2-CP achieved highest degradation with MTN synthesised using anionic surfactant [ABSTRACT FROM AUTHOR]

The aim of this study is to investigate the effect of a co-doped zinc oxide (ZnO) semiconductor nanostructure (Al and Cu) on the dielectric and electro-optical properties of nematic liquid crystal structures. Firstly, Al:ZnO, Cu:ZnO, and (Al-Cu):ZnO (co-doped ZnO) semiconductor nanomaterials were synthesized by a microwave-assisted gel ignition method. Then, new composite structures were formed by doping the synthesized nanomaterial to the nematic liquid crystal. Significant physical parameters including the real and imaginary components of complex dielectric permittivity ( ε ′ and ε ″ ), relaxation frequency ( f R ), relaxation time (τ ), dielectric strength ( δ ε ′ ), and threshold voltage ( V th ) values were determined using the experimental results. The results showed that Al:ZnO and Cu:ZnO doping into liquid crystal (LC) enhanced the properties of E7 nematic LC. Furthermore, it was observed that the co-doped ZnO contribution to the LC significantly improved the dielectric properties and was found to yield the best results. [ABSTRACT FROM AUTHOR]

[2.2]-Paracyclophane derivatives have been promising platforms for applications in biology and materials science. To access pure derivatives thereof, a safe and non-toxic synthetic method for 4- n -propyl-[2.2]-paracyclophane is developed via a microwave-assisted and NH2NH2/KOH reduction route. We introduce microwave-assisted acylation for a synthesis that successfully improves the yield and reduces the reaction time. Notably, an exploration of the length and number of the alkyl chains on the [2.2]-paracyclophane ring did not significantly affect the outcome of this reaction. We synthesized 4- n -butyl-[2.2]-paracyclophane and 4,12-dipropyl-[2.2]-paracyclophane via our protocol with high yields. The regioselectivity of the second electrophilic substitution on 4- n -propyl-[2.2]-paracyclophane occurs at the para position of the less substituted phenyl ring. [ABSTRACT FROM AUTHOR]

A facile approach to synthesise V2O5 nanoflowers are adopted through the microwave-assisted method. The as-prepared V2O5 was characterised by the X-ray diffraction, scanning electron microscopy analyses. The X-ray diffraction spectra confirmed the formation of the orthorhombic crystal structure of V2O5 nanoflowers with an average crystallite size of 20 nm. FTIR results showed the V-O-V stretching mode vibration at 442 cm−1. The above material has studied as cathode material for lithium-ion batteries (LIB) at C/10 rate and the results showed, V2O5 nanoflowers delivered the specific capacity of 241 mAh g−1 than the commercial V2O5 of 98 mAh g−1 at 1.5–4.0 V apart from this, better cycle stability over 100 charge-discharge cycles and reasonable discharge capacities obtained at high C-rates. These results suggest enhancement of LIB capacity due to high surface area and good porosity of mesoporous V2O5 nanoflowers. [ABSTRACT FROM AUTHOR]

Natural rubber (NR)-based composites or hybrid products obtained from NR and several nano-materials are of interest due to their wide range of applications. However, they are easily contaminated with bacteria or fungi that can affect human health, especially those used in food container and on human skin. Herein, we present the composite sheets of NR latex and silver nanoparticles (AgNPs) with exceptionally high antibacterial activities. AgNPs were firstly synthesized by a facile, rapid, and green microwave-assisted method using curcumin as a biomaterial reductant and stabilizer. Then, natural rubbers loaded with AgNPs (NR/Ag) composite sheets were prepared via a simple direct latex mixing-casting process of NR latex and various contents of AgNPs. The result demonstrated that the synthesized AgNPs had a spherical-like shape of 12.25±3.13 nm. All the prepared NR/Ag composite sheets exhibited high performance in antibacterial properties against Staphylococcus aureus and Escherichia coli, and the antibacterial activities were dependent on the loaded AgNPs content. In this study, it is anticipated that these rapid, simple, green, and effective methods can suitably be scaled up for large-scale preparation of the stabilized AgNPs colloid and NR/Ag composite products. [ABSTRACT FROM AUTHOR]

Selenylation Astragalus polysaccharides (Se-APS) was fabricated by an optimized microwave-assisted method. Their physicochemical properties, antioxidant capacities and selenium (Se) release rate under gastrointestinal conditions were determined. Se-APS with the highest Se content (18.8 mg/g) was prepared in 0.4 % nitric acid, under the microwave conditions of 90 min and 80 °C. FTIR and XPS spectra indicated that Se was bound to the polysaccharide chain in the form of O-Se-O and O-H···Se, and most of Se+4 was reduced to Se0. Meanwhile, the micromorphology of Se-APS became clusters, loose and porous, which decreased its hydrodynamic particle size and negative surface charges. Besides, Se-APS displayed strong scavenging capacities towards ABTS and superoxide anion free radicals than Na 2 SeO 3 , and showed higher Se release rate (12.52 ± 0.31 %) under intestinal fluid comparing with gastric fluid (3.14 ± 0.38 %) during 8 h in vitro digestion. The results provided efficient preparation method references for selenylation polysaccharides, and broaden the application fields of APS. [Display omitted] • The selenylation modification of APS by a microwave-assisted method was achieved. • The Se content under optimum Se-APS preparation condition was 18.8 mg/g. • The valence state of Se in Se-APS was composed of +4 and 0. • Se-APS had good ABTS and superoxide anion free radical scavenging capacities. • Se-APS had higher Se release rate (12.52 ± 0.31 %) under intestinal fluid in vitro. [ABSTRACT FROM AUTHOR]

Nanocomposites comprising nitrogen-doped TiO2 and reduced graphene oxide (N/TiO2/rGO), with different rGO loading qualities, were prepared by a cost-effective microwave-assisted synthesis method. The synthesized materials were broadly characterized by Raman spectroscopy, X-ray diffraction (XRD), infrared spectroscopy (FTIR), photoelectron spectroscopy (XPS), diffuse reflectance spectroscopy (DRS), electron microscopy (SEM-EDS), and nitrogen adsorption/desorption isotherms. Anatase was the only crystalline phase observed for all synthesized materials. The rGO loading did not affect the morphological properties, but it positively influenced the photocatalytic activity of the nanocomposite materials, especially at low rGO loading. Photocatalysts were evaluated via the degradation of specific organic micropollutant (OMP) pharmaceuticals: ciprofloxacin (CIP), diclofenac (DCF), and salicylic acid (SA), under different radiation sources: ultraviolet A (UVA), solar light simulator (SLS), blue visible light (BVL) and cold visible light (CVL). CIP and SA were removed effectively via the synergy of adsorption and photocatalysis, while DCF degradation was achieved solely by photocatalysis. After implementing scavenger agents, photocatalytic degradation processes mainly depended on the specific pollutant type, while irradiation sources barely defined the photocatalytic mechanism. On the other hand, changes in irradiation intensity significantly influenced the photolysis process, while photocatalysis was slightly affected, indicating that irradiation spectra are more relevant than intensity. [ABSTRACT FROM AUTHOR]

In this study, inorganic-organic hybrid CdSe(en) 0.5 nanosheet (NS) was developed on Cd foil via the microwave-assisted (MW) method with different MW irradiation cycles. Furthermore, the photoelectrochemical (PEC) performance of the mother material was improved through a second hydrothermal method with different time variations (3, 6, and 12 h at 160 °C). After the second hydrothermal, organic moieties were removed, and a porous photoanode was obtained. The optimized CdSe-6H photoanode showed a photocurrent density of 7.4 mA cm -2 (0  V vs Ag/AgCl) with 272 μmol cm -2 /3h hydrogen gas evolution under one sun illumination. The enhanced PEC performance was attributed to the topotactic transformation, improved light absorbance, enhanced charge separation, and improved surface area. This work offers a rational approach for building inorganic-organic electrodes through the MW method and porous photoanode for PEC hydrogen production., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

A fast, simple, and energy-saving microwave-assisted approach was successfully developed to prepare carbon microspheres. The carbon microspheres with a uniform particle size and good dispersity were prepared using glucose as the raw material and HCl as the dehydrating agent at low temperature (90°C) in an open system with the assistance of microwave heating. The carbon microspheres were characterized by elemental analysis, XRD, SEM, FTIR, TG, and Raman. The results showed that the carbon microspheres prepared under the condition of 18.5% (v/v) HCl and heating for 30 min by microwave had a narrow size distribution. The core–shell structure of the carbon core and TiO2 shell was prepared with (NH4)2TiF6, H3BO3 using the microwave-assisted method. The hollow TiO2 microspheres with good crystallinity and high photocatalytic properties were successfully prepared by sacrificing the carbon microspheres.

We have successfully synthesized multi-layer graphene oxide and graphene oxide based magnetic nanocomposite (M/GO) by microwave-assisted modified Hummers' method for removal of toxic lead (Pb2+) and cadmium (Cd2+) ions from aqueous solution. The X-ray diffraction spectra of synthesized graphene oxide and M/GO confirm increased interlayer spacing along c-axis. Raman spectra revealed the good quality of synthesized GO and M/GO. The wrinkles were seen in the SEM images of synthesized graphene oxide. The presence of conjugated double bond (C C) and carbonyl (C O) were confirmed by using the UV–Vis spectroscopic spectra. Brunauer–Emmett–Teller (BET) analysis showed high (126 m2/g) surface area M/GO composite which accounts for large number of active binding sites for the adsorption of heavy metal ions. The adsorption studies revealed that Pb2+ ions were efficiently adsorbed on GO sheets. Interestingly, M/GO showed better adsorption for cadmium ions. Addition of stock solution of Pb2+ and Cd2+ ions to M/GO solution, removal of M/GO containing Pb2+, and Cd2+ ions using Neodymium magnet. [Display omitted] [ABSTRACT FROM AUTHOR]

The twenty-first century has been witnessing much development in the technological aspect, particularly in optoelectronic device. In this continuation, we have prepared V2O5@WO3 nanocomposites for dielectric application. The proposed titled composites were prepared by a simple and cost-effective microwave-assisted wet chemical method. Subsequently, as-prepared composites were investigated by various characterization techniques. The structural and morphological analysis showed aggregated grain and rapid grain growth. The presence of functional group and elemental analysis were studied. The thermal analysis showed the thermal stability of as-prepared material. The dielectric studies demonstrated excellent dielectric behaviour with respect to temperature and frequency which would meet the required quality for optoelectronics application. [ABSTRACT FROM AUTHOR]

Microwave synthesized activated carbon utilizing Tridax procumbens flowers is reported as supercapacitor electrode. Incomplete graphitization with disordered carbon structure and honeycomb-like surface morphology is achieved. In aqueous H2SO4 electrolyte, the material exhibits charge storage through non-faradaic, electrostatic accumulation/adsorption of charges at electrode-electrolyte interface. The charge/discharge curves confirm the capacitive behavior of the material with a specific capacitance of 168 F g−1 at a current density of 0.5 A g−1. A notable energy density of 2.46 W h kg−1 at a 163 W kg−1 power density is achieved in the assembled symmetric device making it a pertinent electrode material for supercapacitors.

We have reported the preparation and characterization of both pure and Cu2+ doped Cr2O3 nanoparticles with different dopant concentrations by the simple, cost-effective microwave-assisted method. As-prepared samples have undergone various characterizations to get an insight into the Cr2O3 nanoparticles. The XRD pattern showed the rhombohedral phase structure of Cr2O3 with an average particle size of ±14 nm. The surface and morphology analysis (FESEM and TEM) revealed a nearly spherical shape with an average particle size of 30–50 nm and the presence of the elemental composition of Cr and Cu was confirmed by the EDAX spectrum. The optical properties (UV–Vis and PL spectra) of Cr2O3 nanostructures were also studied, and results were found to support our further studies. Finally, electrical and dielectric characterization showed enhanced electrical conductivity concerning temperature and frequency. Highlights: Pure and Cu-doped Cr2O3 nanostructures were successfully synthesized. Spherical shape morphology with loosely agglomeration was observed. Electrical studies showed enhanced dielectric constant with temperature. High conductivity of Cu-doped Cr2O3 was in consequence of polaron hopping. [ABSTRACT FROM AUTHOR]

Nanocomposites comprising nitrogen-doped TiO2 and reduced graphene oxide (N/TiO2/rGO), with different rGO loading qualities, were prepared by a cost-effective microwave-assisted synthesis method. The synthesized materials were broadly characterized by Raman spectroscopy, X-ray diffraction (XRD), infrared spectroscopy (FTIR), photoelectron spectroscopy (XPS), diffuse reflectance spectroscopy (DRS), electron microscopy (SEM-EDS), and nitrogen adsorption/desorption isotherms. Anatase was the only crystalline phase observed for all synthesized materials. The rGO loading did not affect the morphological properties, but it positively influenced the photocatalytic activity of the nanocomposite materials, especially at low rGO loading. Photocatalysts were evaluated via the degradation of specific organic micropollutant (OMP) pharmaceuticals: ciprofloxacin (CIP), diclofenac (DCF), and salicylic acid (SA), under different radiation sources: ultraviolet A (UVA), solar light simulator (SLS), blue visible light (BVL) and cold visible light (CVL). CIP and SA were removed effectively via the synergy of adsorption and photocatalysis, while DCF degradation was achieved solely by photocatalysis. After implementing scavenger agents, photocatalytic degradation processes mainly depended on the specific pollutant type, while irradiation sources barely defined the photocatalytic mechanism. On the other hand, changes in irradiation intensity significantly influenced the photolysis process, while photocatalysis was slightly affected, indicating that irradiation spectra are more relevant than intensity.

ZnFe 2 O 4 nanoparticles/S, N co-doped carbon nanotube composites were prepared by a microwave-assisted method with low cost, low energy consumption and easy commercialization. Through the strategies of nanosizing, heteroatom doping, and compounding with advanced carbon materials, the inherent disadvantages of poor electronic conductivity and low ion diffusion rate of transition metal oxides are improved, and the volume expansion of ZnFe 2 O 4 during cycling is slowed down by using carbon nanotubes with high specific surface and high mechanical strength as the material support skeleton, which enhances the cycling stability of the material. At a current density of 0.1 A g−1, the specific capacity of 716.23 mAh g−1 was maintained after 100 charge/discharge cycles. The charge/discharge cycle at a high current of 2 A g−1 still has a specific capacity of 309.90 mAh g−1. • Carbon nanotubes provide a nucleation site for Znfe 2 o 4 and reduce its size. • Carbon nanotubes reduce material agglomeration and improve cycle stability. • The introduction of S and N atoms creates more defects and active sites. • ZnFe2O4/SNCNT maintain a reversible capacity of 716.23 mAh g-1 after 140 cycles. [ABSTRACT FROM AUTHOR]

• Ni/CeO 2 catalysts were prepared by co-precipitation with different heating treatments. • Heating treatments included microwave, hydrothermal and evaporation. • Performance of Ni/CeO 2 catalysts was evaluated in a packed-bed reactor at 200–500 °C. • Reduction temperatures of Ni species were affected by heating treatments. • Superior performance of Ni/CeO 2 −MW was due to the uniform dispersion of Ni on CeO 2. In thid study, Ni/CeO 2 catalysts were prepared by a one-step co-precipitation of nickel and cerium salts in a NaOH solution treated by different heating methods including microwave (MW), hydrothermal (HM) and evaporation (EP). With TEM observation, the co-precipitation provided the catalysts containing a highly crystalline CeO 2 of a (111) plane structure with d -spacing of 3.15–3.24 Å. The obtained CeO 2 nanoparticles exhibited a pseudo-spherical shape with a size range of 10.8–12.1 nm. Based on HR-TEM analyses, NiO nanoparticles with a large size range of 48.8–51.2 nm were found to be incorporated within the CeO 2 nanostructure. By N 2 sorption measurement, all Ni/CeO 2 catalysts possessed a mesoporous characteristic with a specific surface area range of 70.5–75.7 m2/g and an average pore diameter of 30 nm. XRD results revealed that NiO species could be completely transformed into Ni0 species by the H 2 reduction process. XPS analyses further confirmed the presence of Ni0 species with a prominent peak at an energy bandgap of 852.6 eV. Hydrogen temperature-programmed reduction (H 2 -TPR) confirmed that α and β peaks of NiO species were completely reduced at a temperature lower than 500 °C. The Ni/CeO 2 catalyst prepared by MW method exhibited a higher strong metal-support interaction (SMSI) between Ni and CeO 2 revealed by H 2 consumption results. The Ni/CeO 2 catalysts prepared by MW, HM, EP methods exhibited the CO 2 methanation activity with TOF of 13.6, 10.8 and 5.8 s−1, which could be correlated with the Ni crystallite sizes of 42.2, 50.5 and 52.8 nm, respectively. All prepared Ni/CeO 2 catalysts exhibited the stable catalytic performances with a negligible drop in CO 2 conversion and CH 4 selectivity over 72 h-time-on-stream test. In comparison, the MW method with a rapid and uniform heating under autogenous pressure could result in the Ni/CeO 2 catalyst with the superior catalytic activities due to the higher dispersion of Ni. [Display omitted] [ABSTRACT FROM AUTHOR]

Reduced-graphene oxide/polypyrrole nanofiber (RGO/PPy-Nf) nanocomposite has been prepared as the electrode material of the supercapacitor. This nanocomposite was prepared via a facile two-step process, including exfoliation and reduction of graphene oxide by microwave irradiation (MRGO) and in situ polymerization pyrrole onto it. The morphological, structural, and porosity characterizations of this nanocomposite were shown the proper formation of RGO/PPy-Nf composite with a mesoporous structure. The high specific capacitance of 277 F g−1 was obtained for the RGO/PPy-Nf nanocomposite at a constant current density of 1 A g−1 in a 1 M H2SO4 solution electrolyte. This nanocomposite revealed the highest energy density of 38.5 Wh kg−1 with a corresponding power density of 500 W kg−1, and the capacitive retention of 95% after 1000 cycles. In evaluating the samples by electrochemical impedance spectroscopy, the values of capacitor response time revealed that the dominant mechanism in pristine PPy and MRGO is faradaic reactions and electrical double-layer capacitance (EDLC), respectively, and both mechanisms play a role in the RGO/PPy-Nf nanocomposite. Also, the relaxation time investigation revealed this nanocomposite exhibit an ideal capacitive behavior at very low frequency. [ABSTRACT FROM AUTHOR]

Herein, we proposed a simple and efficient microwave-assisted preparation method for the fabrication of zirconium (IV) intercalated expanded graphite (Zr-EG). The synthetic approach could be completed in one step within 20 s, where KMnO4 was used as the oxidizing agent, H2SO4 and ZrOCl2 as the intercalating agents. The as-prepared Zr-EG exhibited thin multi-layered structure, plenty of small Zr-relevant particles and oxygenated groups in both layers and surface, which gave Zr-EG high absorption capability. Subsequently, the Zr-EG, as a new kind of solid-phase extraction absorbent, was applied to the separation, purification and enrichment of chlorpyrifos in honey samples, followed by high-performance liquid chromatography analysis. Under optimal extraction and analysis conditions, the detection limit was 100 ng g−1. The relative standard deviations ranged from 2.6 to 6.8%. At three spiked levels (1, 10, 100 μg g−1), the recoveries of chlorpyrifos were in the range of 86.1–92.2%. Comparison with other conventional solid-phase extraction adsorbents, modified EG showed rapid synthesis, layered modification flexibility, stable structure, large adsorption capacity and good selectivity, demonstrating great potential in pollutants separation and detection. [ABSTRACT FROM AUTHOR]

A simple, low-cost and an eco-friendly synthesis of Ir-doped titanium dioxide nanoparticles (TiO2 NPs) with an anatase phase by the microwave-assisted method using an aqueous solution of titanium tetra-isopropoxide (TTIP) and iridium (III) chloride monohydrate. The synthesized Ir-doped TiO2 NPs were characterized by using various spectro-analytical techniques for the confirmation of NPs. The photocatalytic activity of the synthesized Ir-doped TiO2 NPs has been evaluated by taking 2-chlorophenol (2-CP), 4-chlorophenol (4-CP), 2,4-dichlorophenol (2,4-DCP) and 2,4,6-trichlorophenols (2,4,6-TCP) as model water contaminant pollutants under sunlight irradiation. The photocatalytic conversion is approximately 84.24%, 81.22%, 76.01% and 72.11% of 2-CP, 4-CP, 2,4-DCP and 2,4,6-TCP respectively, by using the synthesized Ir-doped TiO2 NPs. The efficient photocatalytic degradation was observed in the degradation of 2-CP in 60 min of sunlight irradiation. The rate equation of photocatalytic degradation mechanism was followed pseudo-first order kinetics. Finally, the screening of antimicrobial activity by paper disc method against few bacteria, such as Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa), Bacillus subtilis (B. subtilis) and Staphylococcus aureus (S. aureus) and fungi such as Aspergillus niger (A. niger) and Candida albicans (C. albicans), showed that the prepared Ir-doped TiO2 NPs have the prominent results.

Multi-walled carbon nanotubes-titanium dioxide (MWCNTs-TiO2) nanocomposites were synthesized via microwave-assisted synthesis and conventional hydrothermal method, comprising of well-crystallized anatase TiO2 nanoparticles with different MWCNTs contents. TiO2 nanoparticles synthesized by the rapid thermal decomposition of tetra-butyl titanium (Ti(OC4H9)4) in the presence of acid treated MWCNTs, were attached on the surface of MWCNTs by means of chemical bonds under microwave irradiation. The addition of MWCNTs did not influence the structure of anatase TiO2. The photocatalytic performance evaluation of composite materials was conducted under UV and visible light using methyl orange (MO) as a typical pollutant. The enhancement in photocatalytic efficiency of nanocomposites was clearly observed by the presence of MWCNTs, which could contribute to improve the adsorption of MO dye, absorption of more light and also obstruct the photogenerated electron-hole pair's recombination. [ABSTRACT FROM AUTHOR]

Layered hydrazinium titanate (LHT-9) has been synthesized by reflux and microwave routes and evaluated for its potential application for sequestration of radionuclides from nuclear waste. Synthesized materials have been characterized using X-ray diffraction, scanning electron microscopy, X-ray absorption spectroscopy and uptake of radionuclides. The LHT-9 obtained by the microwave route appears more ordered than that obtained using the reflux process. However, both are comprised of TiO6 octahedra. Post loading of species such as Sr, the octahedral ordering within the layers remains intact. Considering the uptake behaviour and the possibility of scale-up, LHT-9 synthesis using the microwave route may provide advantages in nuclear waste treatment applications. [ABSTRACT FROM AUTHOR]

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In this study, groundwater of 10 union councils of Larkana city was assessed by using atomic absorption spectrometry following microwave-assisted digestion. A total of 110 groundwater samples were collected by using a Global Positioning System. The results revealed that iron, zinc, nickel, copper, and lead present in the groundwater of Larkana city were within the level of 0.002–0.6 mg/L, 0.02–0.42 mg/L, 1–14.0 mg/L, 0.01–0.87 mg/L, and 0.01–12.0 mg/L, respectively. A total of 38% and 16% of samples showed a higher concentration of iron and lead, respectively. While other elements in the analyzed samples were within the safe limits set by WHO guidelines. [ABSTRACT FROM AUTHOR]

The combination of metallic and carbon components offers tremendous advantages in the development of advanced composites for electromagnetic wave absorption (EMWA) applications. Herein, hollow (NiCo) x /(MnO) y /C microspheres (MSs) possessing hierarchically porous structures were successfully synthesized via a facile microwave-assisted method followed by a carbonization step. The EMWA performance of the (NiCo) x /(MnO) y /C MSs in the K-band region could be tuned and optimized by adjusting the NiCo/Mn molar ratio, with a NiCo/Mn ratio of 1:1 affording the best EMWA performance. The NiCo/MnO/C MSs exhibited a minimum reflection loss value of -32.3 dB (at 21.4 GHz) and an effective absorption bandwidth (EAB, RL ≤ −10 dB) of 8.33 GHz (from 18.17-26.5 GHz) at a thickness of only 1.0 mm in the K band. The excellent EMWA performance of the (NiCo) x /(MnO) y /C MSs composites can be attributed to a strong EMW attenuation capacity and good impedance matching, which arise through the synergistic action of the components (NiCo alloy, MnO and C) and hierarchical pores. Image 1 [ABSTRACT FROM AUTHOR]

The production of different size and shape silver nanoparticles (AgNPs) has increased considerably in recent years due to several commercial and biological applications. Here, rod‐shaped AgNPs (SNRs) were prepared using the microwave‐assisted method and characterised by ultraviolet–visible spectroscopy, and transmission electron microscopy analysis. The present study aims to investigate the cyto–genotoxic effect of various concentrations (5, 10, and 15 µM) of SNRs using Allium cepa model. As a result, concentration‐dependent cyto–genotoxic effect of SNRs was observed through a decrease in the mitotic index, and an increase in the chromosomal aberrations such as chromosome break, disturbed metaphase, and anaphase bridge. To check the impact of Ag+ ions, 15 µM silver nitrate (AgNO3) was prepared and tested in all the assays. Furthermore, cell viability and different reactive oxygen species assays were performed to test the cytotoxicity evaluation of SNRs. The authors found that in all the tested assays, SNRs at high concentrations (15 µM) and AgNO3 (15 µM) were observed to cause maximal damage to the roots. Therefore, the current study implies that the cytotoxicity and genotoxicity of SNRs were dependent on the concentration of SNRs. [ABSTRACT FROM AUTHOR]

The influence of precursor solution pH on phase, morphology and optical properties of BiOIO3 was investigated in this research. The products were synthesized in the solutions with the pH of 2, 3, 4, 5 and 6 by a 360 W microwave (2.45 GHz) at 5 min/cycle for 12 cycles (60 min) and were well characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, selected area electron diffraction, UV–visible spectroscopy, photoluminescence spectroscopy and Brunauer–Emmett–Teller surface area analysis. According to the analytical results, pure BiOIO3 nanoplates were synthesized at the pH of 2 and 3 and were transformed into pure Bi2O3 nanoparticles at the pH of 6. The photocatalytic activities of products were studied through the degradation of rhodamine B solutions under visible light irradiation. The as-synthesized BiOIO3 nanoplates with band gap energy of 2.90 eV synthesized at the pH of 3 have the highest decolorization efficiency of 97.9% and pseudo-first-order degradation rate of 0.0442 min−1 within 60 min. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

[Display omitted] • NiFe 2 O 4 -CoFe 2 O 4 nanocomposites (NF-CF NCs) were synthesized by microwave-assisted method. • NF-CF NCs were characterized by structural, morphological and optical studies. • NF-CF NCs showed promising photocatalytic activity against Rose Bengal and Methylene blue dyes under visible light irradiation. • Photoelectrochemical hydrogen production was tested in the presence NF-CF NCs. Microwave radiation assisted method is emerged as a promising method due to its environmental friendliness, less time and no need toxic or harsh reagents. Herein, we report the synthesis of a NiFe 2 O 4 -CoFe 2 O 4 nanocomposites by microwave radiation assisted method and its characterisation using various methods. X-ray Diffractogram (XRD) studied revealed the spinel cubic structure of the NiFe 2 O 4 -CoFe 2 O 4 nanocomposites having an average crystallite size of 34 nm. Tetrahedral (594 cm−1) and octahedral (397 cm−1) sites of NiFe 2 O 4 -CoFe 2 O 4 are identified by Fourier Transform Infrared (FTIR) spectroscopy as it is having the typical vibrational frequencies. UV–Visible diffuse reflectance (UV–Vis DRS) spectrum indicated that optical bandgap is less for nanocomposites compared to individual components. Transmission electron microscopy (TEM) images show the spherical nature of the nanocomposites. The photocatalytic degradation study of microwave-assisted NiFe 2 O 4 -CoFe 2 O 4 nanocomposites is investigated under visible light irradiation against the Rose Bengal and Methylene blue dyes. The developed nanocomposites exhibited enhanced photoelectrochemical hydrogen due to higher charge separation and faster charge transfer at the interface. [ABSTRACT FROM AUTHOR]

Abstract In this study, graphene oxide (GO) was eco-friendly and reduced with microwave-assisted method to form reduced graphene oxide (rGO). Two components of nanocomposite of rGO and Ruthenium oxide (RuO 2) (rGO/RuO 2) and a ternary components of nanocomposite of rGO, RuO 2 and polyvinylcarbazole (PVK) (rGO/RuO 2 /PVK) were synthesized via in-situ polymerization technique. These nanocomposite materials were characterized by Fourier-transform infrared spectroscopy-attenuated transmission reflectance (FTIR-ATR), scanning electron microscopy (SEM), and energy-dispersive X-ray analysis (EDX), thermal-gravimetric (TGA-DTA) analysis, transmission electron microscopy (TEM), X-ray diffraction (XRD), and BET surface analysis. Supercapacitor device performances were taken by cyclic voltammetry (CV), galvanostatic charge/discharge (GCD), and electrochemical impedance spectroscopy (EIS) used as two electrode configuration. The highest specific capacitance (C sp) was obtained as C sp = 2698 F/g at 2 mV/s for rGO/RuO 2 /PVK nanocomposite at initial feed ratio of [rGO] o /[RuO 2 ] o /[9-VK] o = 1:1:5. Besides, the highest energy and power density values were obtained as E = 17.711 Wh/kg and P = 2684.36 W/kg for rGO/RuO 2 nanocomposite. Ragone plots were drawn to observe energy and power density of supercapacitor devices. Stability tests were examined by CV method for 1000 cycle. Graphical abstract Image 1 Highlights • The highest specific capacitance was obtained for rGO/RuO 2 /PVK nanocomposite. • LR 1 (QR 2 (CR 3)) circuit model evaluation was performed for rGO/RuO 2 /PVK nanocomposite. • Supercapacitor device performances were applied for rGO/RuO 2 /PVK nanocomposite. [ABSTRACT FROM AUTHOR]

Highlights • BiF 3 /BiOBr with higher photodegradation ability was synthesized by a fast and stable microwave-assisted method. • The O 2 − and h+ were the main active species in the oxidation of RhB. • Improvement of photocatalytic activity was owed to high photoelectron-hole separation efficiency. Abstract Novel BiF 3 /BiOBr heterojunction photocatalysts were prepared from a fast and stable microwave-assisted method, and characterized by X-ray diffractometry, X-ray photoelectron spectroscopy, scanning electron microscopy, ultraviolet-visible spectroscopy and fluorescence spectroscopy. The photocatalytic activity of BiF 3 /BiOBr heterojunctions under light irradiation was significantly higher than pure BiOBr or BiF 3 , and was maximized at the Br:F molar ratio of 1:1, as the targeted 20 mg/L Rhodamine B (RhB) solution was completely degraded within 40 min. This was mainly because the unique BiF 3 /BiOBr heterojunction formed during photocatalytic degradation accelerated the photoelectron and hole separation, effectively enhanced the quantum efficiency, and thereby strengthened the photocatalytic activity. [ABSTRACT FROM AUTHOR]

Abstract The Ni-rich layered oxide (NLO) cathode materials play a key role in developing high-energy-density lithium ion battery (LIB) for wide scale deployment of clean transportation technologies. However, surface reconstruction from a layered structure to a mixed spinel/rock-salt structure during charge/discharge cycles is related to the severe voltage decay and capacity fading of the stoichiometric NLO cathode materials, thus thwarting the practical implementation. Herein, we report a heterostructured NLO cathode that tackles the structural degradation and related voltage decay problems. The efficient internal "incore" volumetric heating by direct coupling of microwave energy induces formation of Ni, Co-rich core and Al-rich shell. As a result of the encapsulation of the atomically ordered NiAl 2 O 4 after heat treatment, the solid/electrolyte interphase and surface structure of NLO cathode remains stable. By applying this NiAl 2 O 4 /NLO heterostructured material as a cathode, we demonstrate its robustness in suppressing the voltage decay (0.8% after 100 cycles) during high-voltage cell operation. Rather than the typical modifications, our work explores a more efficient structure engineering process for applications in nano-/micro-manufacturing transition-metal based electrode materials and sheds light on developing high-performance LIB in the near future. [ABSTRACT FROM AUTHOR]

ZrO2 nanoparticles were prepared by the microwave-assisted method. XRD, FTIR, FESEM with EDS, TEM, UV-Vis, and photoluminescence were used for the characterization of ZrO2 nanoparticles. XRD exhibits cubic structure with an average crystallite size of 12 nm. FESEM and TEM images confirm the nanoparticles with an average particle size of 35 nm. From FTIR results, the characteristic vibrational band (Zr-O) is observed at 735 cm−1. The optical bandgap of the microwave-assisted ZrO2 nanoparticles is found to be 4.42 eV. The photoluminescence spectrum of ZrO2 nanoparticles showed blue, green and orange emissions. The photocatalytic degradation study of ZrO2 nanoparticles was investigated against the Methylene Blue (MB) and Rose Bengal (RB) dyes under UV light irradiation. Microwave-assisted ZrO2 nanoparticles showed an excellent photocatalytic activity (MB and RB dye) monitored by using UV-Vis spectrophotometer. Antibacterial activity (disc diffusion method) of microwave-assisted ZrO2 nanoparticles was studied against foodborne pathogens. Furthermore, microwave-assisted ZrO2 nanoparticles will be applicable to wastewater remediation and pharmaceutical applications. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Cu/Fe-AO-PAN fiber was prepared by a facile and rapid microwave-assisted method. • The fiber showed nearly 100% of PNP removal rate under visible light irradiation. • The fiber exhibited good pH tolerance, photocatalytic activity and stability. Abstract A visible-light responsive Cu-Fe bimetallic amidoxime-modified polyacrylonitrile (denoted by Cu/Fe-AO-PAN) fiber was prepared using a facile and rapid microwave-assisted synthesis method. Several microscopic and spectroscopic techniques were adopted to characterize the morphology, structure, thermal and optical properties of the Cu/Fe-AO-PAN fiber. The results indicated that Cu2+ and Fe3+ ions were successfully coordinated with AO-PAN without causing distinct damage to the fiber and that chelation with metal ions extended the light absorption into the visible-light region. P-nitrophenol (PNP) was used to investigate the photocatalytic performance of the Cu/Fe-AO-PAN fiber in a photo-Fenton system under visible light irradiation. Various parameters that affected PNP removal were discussed, including the microwave heating temperature, irradiation time, Cu/Fe molar ratio, and photo-Fenton reaction conditions, such as the pH, H 2 O 2 concentration and fiber dosage. Under the optimal conditions, a PNP removal rate of approximately 100% was achieved within 150 min under visible light irradiation. The bimetallic Cu/Fe-AO-PAN exhibited improved pH tolerance, photocatalytic performance and stability compared to the monometallic Fe-AO-PAN fiber. In addition, a mechanism for PNP degradation induced by the Cu/Fe-AO-PAN fiber in the photo-Fenton system under visible light irradiation was proposed. [ABSTRACT FROM AUTHOR]

Microwave (MW)-assisted acid hydrolysis of lignocellulosic material derived from bode (Styrax tonkinensis) wood to glucose was performed to find effective uses for discarded chopsticks. The maximum amount of glucose produced by MW-assisted acid hydrolysis (from 1 g of untreated bode wood cellulose) was 0.48 g, and was obtained by heating at 200 °C for 1 min using 1.0% (w/w) sulfuric acid as catalyst. However, the maximum total glucose yield from both MW-assisted acid hydrolysis (0.16 g) and enzymatic hydrolysis of the treated residue (0.52 g) was 0.68 g, which was obtained at a microwave heating temperature of 180 °C for 5 min using 1.0% (w/w) sulfuric acid as catalyst. In conclusion, the results showed that microwave-assisted treatment at 200 °C using 1.0% (w/w) sulfuric acid as catalyst facilitated MW-assisted acid hydrolysis of bode wood cellulose and treatment at 180 °C served as pretreatment for enzymatic hydrolysis of the treated residue. [ABSTRACT FROM AUTHOR]

Abstract In this work, an eco-friendly and convenient microwave-assisted synthesis technique was applied in the entire experiment course. The first obtained graphene-Ni composite possess an unsatisfactory microwave absorption capacity due to unbalanced matching nature. Then a sulfurization process was tried at different temperatures to convert Ni into NiS/Ni 3 S 2 , and an innovative graphene-NiS/Ni 3 S 2 composite with a hierarchical architecture was fabricated under the condition of microwave irradiation. The investigation into microwave absorbing performances manifests that the absorption property of graphene-Ni can be obviously improved by sulfurization method. The results show, compared with graphene-Ni, the hierarchical-architecture graphene-NiS/Ni 3 S 2 composites generated at 150 ℃ (S-150) possess excellent absorbing ability with a maximum RL as strong as − 55.1 dB at 6.0 GHz with a thickness of 2.7 mm, and the effective bandwidth covers 8.6 GHz from 2.8 to 11.4 GHz with thickness varies in 1.5–4.5 mm range. The enhanced performances for S-150 mainly derive from the synergy of superior impedance matching character, high attenuation, dielectric loss and plenteous interface polarizations. [ABSTRACT FROM AUTHOR]