Flower-like Nanostructures Research Articles

Efficient degradation of rhodamine B by MoS2 modified Co-MOF derived nitrogen-doped carbon activated peroxymonosulfate

How to improve the issues of ion agglomeration and metal ion leaching, and how to prepare cobalt-based catalysts with high reactivity and stability, are highly desired yet challenging. In this paper, MoS2 modified Co-MOF derived nitrogen-doped carbon (Co/PCN/MoS2) microspheres rich in active sites were prepared using a simple carbonation-hydrothermal method, with g-C3N4, MoS2 and Co-MOF to overcome the aforementioned limitations. The flower-like nanostructure of MoS2 contributed to exposing more marginal active sites, allowing the high dispersion of Co-MOF within its structure. Meanwhile, Mo4+/Mo6+ and S species coexisted in MoS2, which promoted the valence cycle and electron transfer process, and improved the catalytic activity of the composite. The successful synthesis of Co/PCN/MoS2 was proved by XRD, SEM and FTIR characterizations. The electrochemical performance analysis showed that Co/PCN/MoS2 exhibited higher redox capacity than MoS2, and Co/PCN/MoS2/PMS system achieved the degradation rate of RhB as high as 97.19% within 30 min, which is higher than that of Co-MOF/g-C3N4/PMS (80.67%), Co-MOF/MoS2/PMS (78.08%), Co-MOF/PMS (77.00%), g-C3N4/PMS (53.68%) and MoS2/PMS (28.10%) systems. It had good anti-interference ability against coexisting substances, achieved good degradation performance in a wide pH range (pH 2.0–10.0), and possessed excellent stability and reusability with RhB degradation rate of 91.10% after 5 cycles. The quenching test confirmed that non free radical 1O2 is the main ROS for RhB degradation. This work is expected to provide a new idea and direction for the design and development of metal-doped heterogeneous catalysts with high activity and stability.

3D self-assembled polar vs. non-polar NiO nanoparticles nanoengineered from turbostratic Ni3(OH)4(NO3)2 and ordered β-Ni(OH)2 intermediates.

A surfactant-free ammonia and carbamide precursor-modulated engineering of self-assembled flower-like 3D NiO nanostructures based on ordered β-Ni(OH)2 and turbostratic Ni3(OH)4(NO3)2 nanoplate-structured intermediates is reported. By employing complementary structural and spectroscopic techniques, fundamental insights into structural and chemical transformations from intermediates to NiO nanoparticles (NPs) are provided. FTIR, Raman and DSC analyses show that the transformation of intermediates to NiO NPs involves subsequent loss of NO3- and OH- species through a double-step phase transformation at 306 and 326 °C corresponding to the loss of free interlayer ions and H2O species, respectively, followed by the loss of chemically bonded OH- and NO3- ions. Transformation to NiO NPs via the ammonia route proceeds as single-phase transition, accompanied with a loss of OH- species at 298 °C. The full transformation to NiO NPs of both intermediates is achieved at 350 °C through annealing in the air atmosphere. Ammonia-derived NPs maintain nanoflower morphology by self-assembling into nanoplates, which is enabled by H2O-mediated adhesion on the NiO NPs' {100} neutral surfaces. Structural transformations of turbostratic Ni3(OH)4(NO3)2 nanoplates result in the formation of NiO NPs dominantly shaped by inert polar OH-terminated (111) atomic planes, leading to the loss of the initial self-assembled 3D structure. DFT calculations support these observations, confirming that H2O adsorbs dissociatively on polar {111} surfaces, while only physisorption is energetically feasible on {100} surfaces. NiO NPs obtained via two different routes have overall different properties: carbamide-derived NPs are 3 times larger (15.5 vs. 5.4 nm), possess a larger band gap (3.6 vs. 3.2 eV) and are more Ni deficient. The intensity ratio of surface optical (SO) modes to transversal and longitudinal optical modes is ∼40 times higher in the NiO NPs obtained from β-Ni(OH)2 compared to Ni3(OH)4(NO3)2-derived NPs. The SO phonon lifetime is an order of magnitude shorter in NiO obtained from β-Ni(OH)2, reflecting a much smaller NP size. The choice of a precursor defines the size, morphology, crystallographic surface orientations and band gap of the NiO NPs, with Ni deficiency providing pathways for utilizing them as p-type materials, allowing for the precise nanoengineering of polar and neutral surface-dominated NiO NPs, which is of exceptional importance for use in catalysis.

Immunomagnetic particles exhibiting programmable hierarchical flower-like nanostructures for enhanced separation of tumor cells.

Immunomagnetic particles are extensively used for the separation of biological molecules and particles, and have exhibited great potential in many fields including biosensors, disease diagnosis and biomedical engineering. However, most immunomagnetic particles exhibit a smooth surface, resulting in a limited separation efficiency for biological particles featuring enormous surface nanostructures, such as tumor cells. Here we report flower-like immunomagnetic particles (FIMPs) prepared by streptavidin (SA)-assisted biomineralization and one-step antibody modification, and demonstrate their superior capability for highly efficient and selective separation of circulating tumor cells (CTCs). SA can link inorganic nanosheets and magnetic nanoparticles together to obtain FIMPs with programmable hierarchical flower-like nanostructures and provide enormous binding sites for post-antibody modification. The synergetic effect of nano-sized petals and micro-sized particles in the hierarchical nanostructure enhances the interaction between the cells and the matrix, thus enabling FIMPs to separate CTCs with high selectivity and high efficiency. Our study provides a promising platform for the selective separation of trace biological molecules and particles from complex samples and shows great potential for downstream detection and diagnosis.

A CoMo@NiC2O4/NF anode and a Pb/CP cathode for a novel direct sodium borohydride-maleic acid fuel cell

CoMo@NiC2O4/NF and Pb/CP electrodes are prepared, which are used as the anode and cathode, respectively, to assemble a novel direct sodium borohydride-maleic acid fuel cell.

Rice husk valorisation by in situ grown MoS2 nanoflowers: a dual-action catalyst for pollutant dye remediation and microbial decontamination.

Rice husk (RH) is a common agricultural waste generated during the rice milling process; however, a major portion is either burned or disposed of in landfills, posing significant environmental risks. In this study, RH waste was transformed into bio-based catalysts via delignification cum in situ growth of MoS2 (DRH-MoS2) for efficient pollutant dye removal and microbial decontamination. The developed DRH-MoS2 exhibits nanoflower-like structures with a 2H-MoS2 phase and a narrow band gap of 1.37 eV, which showed strong evidence of photocatalytic activity. With the presence of abundant hydroxyl functionality, delignified rice husk (DRH) exhibits a malachite green (MG) dye adsorption capacity of 88 mg g-1. However, in situ growth of MoS2 nanosheets on DRH enhances MG degradation to 181 mg g-1 under dark conditions and 550 mg g-1 in the presence of light. Mechanistic insights reveal a synergistic adsorption-cum-degradation phenomenon, amplified by generation of reactive oxygen species during photodegradation which was confirmed from radical scavenging activity. Interestingly, DRH-MoS2 demonstrates potent antibacterial activity against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) with sustained photodegradation efficiency (>80%) over three cycles. The present work reports a cost-effective and scalable strategy for environmental remediation of real wastewater which usually contains both dye pollutants as well as microbes using abundantly available renewable resources such as sunlight and agricultural biomass wastes.

INFLUENCE OF ANNEALING TEMPERATURE ON ZINC OXYSULPHIDE THIN FILMS PROPERTIES DEPOSITED BY THERMAL SPRAY TECHNIQUE

This article studies the effects of annealing temperatures on the stoichiometry, structure, and optical characteristics of Zinc Oxysulphide thin films deposited on glass substrates using the thermal spray method. The annealing was done in the air under a temperature of 150 ºC, 250 ºC and 350 ºC. Field Emission Scanning Electron Microscopy (FESEM), X-ray diffractometry (XRD), and a UV-Vis Spectrophotometer were utilized to examine the thin films' morphological, structure, and optical characteristics as grown and annealed samples. It has been observed that the film thickness decreases as the annealing temperature increases. The XRD pattern demonstrates that as-prepared and annealed samples at 250C, and 350C are amorphous, while film annealed at 150 C is crystalline with the hexagonal phase and orientated along (110) plane. FESEM image of the as-prepared Zinc Oxysulphide thin films shows flower-like sheet nanostructures. However, for the annealed samples, the FESEM images show cone-like with a combination of sheets and aggregate nanoparticles. EDX analysis reveals the presence of Zn, O as well as sulfur. The transmittance of the film decreases from 63% to 37% and the band gap energy reduces slightly from 3.99 to 3.92 eV as the annealing temperature increase.

In situ XPS demonstrated efficient charge transfer of ohmic junctions based on graphdiyne (g-CnH2n-2) nanosheets coupled with porous nanoflowers Ni5P4 for efficient photocatalytic H2 evolution

The photocatalytic hydrogen evolution ability of catalyst can be effectively improved by constructing suitable heterojunction. The present study involves a new type of carbon-material semiconductor graphdiyne (GDY) was prepared by ball milling assisted reduction elimination reaction, and introduced into metal-rich Ni5P4 nanoflowers by hydrothermal method. GDY/Ni5P4 ohm junction was successfully constructed to regulate the electron direction. The C ≡C bond in GDY exhibits high reducibility, which is conducive to inhibiting the oxidation of Ni5P4. The unique porous nanoflower-like structure of Ni5P4 enables it to achieve complete contact with solvents, thereby enhancing proton absorption capabilities. The construction of an ohmic junction is confirmed to induce electron transfer from GDY to Ni5P4 through situ XPS characterization, thereby suppressing the recombination of electron-hole pairs in GDY. Among them, 15%GDY/Ni5P4 has the best photocatalytic hydrogen evolution activity of 11713.6 μmol h−1 g−1, which is about 15 times higher than that of GDY (755.4 μmol h−1 g−1) and 5 times that of Ni5P4 (2369.6 μmol h−1 g−1). This work provides a new way to construct ohm junction based on GDY for photocatalytic hydrogen evolution.

A sensitive electrochemical sensor based on graphene quantum dots/hierarchical flower-like gold nanostructures for determination of cytostatic drug flutamide

Using an electrochemical sensor with high sensing capability and manufacturing simplicity, flutamide (FLU) can be quantitatively measured. A glassy carbon electrode is modified with graphene quantum dots (GQDs) and hierarchical flower-like gold nanostructures (HFGNs). Combining GQDs and HFGNs enhanced the electrode surface and electron transfer rate, improving the signal's intensity and sensitivity. Nanostructure characterization, electrochemical characterization, and detection studies indicated the high performance of the platform in terms of sensitivity, selectivity, reproducibility, and stability. With these improvements, linear correlations were achieved between 0.01 and 400 µM, with a detection limit of 6.2 nM (based on 3Ssb/m). Pharmaceuticals and complex biological samples along with interfering agents have been successfully analyzed with this platform.

Cobalt Oxide 2D Nanosheets Formed at a Polarized Liquid|Liquid Interface toward High-Performance Li-Ion and Na-Ion Battery Anodes.

Cobalt oxide (Co3O4)-based nanostructures have the potential as low-cost materials for lithium-ion (Li-ion) and sodium-ion (Na-ion) battery anodes with a theoretical capacity of 890 mAh/g. Here, we demonstrate a novel method for the production of Co3O4 nanoplatelets. This involves the growth of flower-like cobalt oxyhydroxide (CoOOH) nanostructures at a polarized liquid|liquid interface, followed by conversion to flower-like Co3O4 via calcination. Finally, sonication is used to break up the flower-like Co3O4 nanostructures into two-dimensional (2D) nanoplatelets with lateral sizes of 20-100 nm. Nanoplatelets of Co3O4 can be easily mixed with carbon nanotubes to create nanocomposite anodes, which can be used for Li-ion and Na-ion battery anodes without any additional binder or conductive additive. The resultant electrodes display impressive low-rate capacities (at 125 mA/g) of 1108 and 1083 mAh/g, for Li-ion and Na-ion anodes, respectively, and stable cycling ability over >200 cycles. Detailed quantitative rate analysis clearly shows that Li-ion-storing anodes charge roughly five times faster than Na-ion-storing anodes.

Mo-doped NiCo-LDH nanoflower derived from ZIF-67 nanosheet arrays for high-performance supercapacitors

Layered double hydroxides (LDHs) have gained utmost concern as anode materials for supercapacitors considering their high theoretical specific capacitances, short ion channels and good electrochemical properties. However, their practical application is hindered by low conductivity and limited performance in terms of charge storage. In this study, the researcher successfully synthesized Mo-doped NiCo-LDH nanoflower structures through a straightforward hydrothermal reaction and calcination utilizing lamellar ZIF-67 as a precursor. By adjusting the Mo doping concentration, the researcher was able to maintain the unique multilevel nanoflower-like structure of NiCo-LDH. Furthermore, the inclusion of Mo as a dopant introduced an amorphous phase and effectively modulated the electronic structure of NiCo-LDH, resulting in accelerating charge storage kinetics and reduced volume change. The 0.075 Mo-doped NiCo-LDH exhibited a specific capacitance of 1368.4C g−1 at 1 A g−1, with the capacity retention of 88.4 % at 10 A g−1. Additionally, the assembled asymmetric supercapacitor constructed with 0.075 Mo-doped NiCo-LDH@C//RGO achieved an energy density of 52.2 Wh kg−1 with a power density of 799.3 W kg−1. This study provides valuable insights into the rational doping of Mo elements for the controlled synthesis of supercapacitor electrode materials.

Template preparation of porous Pt-modified SnO2 microflowers for high-response detection of VOCs

Porous SnO2 microflowers consisting of uniform nanosheets modified by Pt nanoparticles were synthesized using a self-sacrificing template followed by a reduction strategy. The Pt@SnO2, SnO2–Se, and SnO2–S samples were characterized using a series of techniques. The gas-sensing behaviors of the samples toward volatile organic compounds (VOCs) were studied. The Pt@SnO2 sensors exhibited superior gas-sensing performance for formaldehyde gas. The Pt@SnO2 sensors presented a stronger response (100.2), shorter response–recovery times (14 s/23 s), and lower working temperature (200 °C) for 100 ppm formaldehyde gas. The Pt@SnO2 sensors also showed excellent responses toward other VOCs, such as 100 ppm ethanol (82.5), acetone (73.9), and isopropanol (62.1). The gas-sensing mechanism of the Pt@SnO2 sensors was examined. The larger available surface area, favorable hierarchical flower-like nanostructure assembled by nanosheets, larger pore size, and larger proportion of oxygen vacancies and adsorption-state oxygen species, smaller crystallite size, and spillover effect of Pt catalysts contributed to the enhanced gas-sensing behaviors of Pt@SnO2 sensors. Overall, the synthetic strategy for flower-like SnO2 nanostructures can be applied widely.

Engineering of Micro-mesoporous two-dimensional CeO2-based heterojunction oxides for energy storage applications

With growing demands on energy supply and storage, there is a need for advanced devices that can meet the high power and energy requirements. One such device is a supercapacitor, which is classified into two types, namely the electrical double-layer capacitor (EDLC) and the pseudocapacitor. Pseudocapacitors show energy storage properties that are between EDLCs and batteries and generally, transition metal oxides are used for these applications. Recent work has demonstrated that CeO2 is a potential material for such applications owing to its reversible charge-switching capabilities and good stability in different environments. In the present work, novel ultrathin nanosheets of CeO2-x and a composite of ruthenium (Ru)-CeO2-x, with the Ru in the form of mixed heteroatoms and dopants were synthesised using a Ce-based coordination polymer (Ce-CP) as the precursor using modified anodic chronoamperometric electrodeposition (MACE) technique. The ready exfoliation of Ce-CP in triethanolamine, which was the exfoliation medium, followed by solvent removal and annealing at 300 °C resulted in the formation of ultrathin 2D CeO2 nanosheets that are partially stacked, resulting in the formation of flower-like 3D nanostructures. The ultrathin 2D CeO2 formed 3D flower-like nanostructures with high concentrations of defects, active sites, and mesopores, which increased with the concentration of Ru in the CeO2-x nanostructure. Additionally, the specific surface area of the Ru-CeO2-x samples was higher, increasing to 354 m2·g−1 compared to the value of 146 m2·g−1 for pristine CeO2-x. The cyclic voltammetry analysis revealed that the introduction of Ru increased the capacitance of pristine CeO2-x from 665 F·g−1 to 923 F·g−1 at a scan rate of 5 mV·s−1. These findings suggest that Ru-CeO2-x nanosheets have potential for use in supercapacitor applications.

In situ synthesis copper phosphate-protein hybrid nanoflower on nickel foam for the sensitive detection of glucose in body fluids

We have synthesized copper phosphate-protein hybrid heterostructure nanoflowers (Cu(II)-HNFs) in situ on nickel foam for the first time. The interaction between protein and copper ions facilitated the nucleation growth of copper phosphate crystals and self-assembly of hybrid nanosheets into exquisite flower-like nanostructures. The unique high-specific surface structure of Cu(II)-HNFs provided high-density catalytically active sites for copper phosphate. Also, the direct growth of Cu(II)-HNFs on the NiF surface enhanced the electron transfer efficiency during catalysis. As a result, Cu(II)-HNFs exhibit an excellent electrocatalytic efficacy in glucose sensing. Including wide linear range of 0.1-3000 μM, high sensitivity of 2497.1 μA mM−1 cm−2, ultra-low detection limit of 0.03 μM, good selectivity, and stability. Moreover, Cu(II)-HNFs@NiF has been validated as a reliable tool for detecting glucose in urine samples, with recoveries ranging from 92.9 % to 101.9 %. These findings demonstrate that the developed Cu(II)-HNFs@NiF has immense potential for non-invasive glucose monitoring through body fluids.

Nanoflower-like graphitic carbon nitride aerogel: Artful cyanuric acid-controlled synthesis and enhanced photocatalytic hydrogen evolution activity

The previously reported studies on cyanuric acid-assembly strategy usually ignores the promoting function of cyanuric acid in the production of g-C3N4, limiting the development of molecular assembly strategies. In this study, a cyanuric acid-controlled synthesis strategy involving the pre-assembly of cyanuric acid with melamine and subsequent one-step calcination was developed to produce a three-dimensional (3D) nanoflower-like graphitic carbon nitride (g-C3N4) aerogel. Some cyanuric acid molecules underwent a polycondensation reaction with melamine during the pre-assembly process and finally polymerized into the g-C3N4 structure during subsequent calcination. Meanwhile, the remaining cyanuric acid molecules assembled with melamine via hydrogen-bond interactions and underwent incomplete decomposition during subsequent calcination, which not only promoted the production of 3D nanoflower-like aerogel structures, but also introduced the carbonyl (CO) and hydroxyl (–OH) groups onto the g-C3N4 surface, resulting in the successful generation of a 3D nanoflower-like oxygen-modified g-C3N4 aerogel. Moreover, the fabricated g-C3N4 aerogel exhibited a greatly enhanced H2 production rate (1573 μmol h−1 g−1), which is ∼ 6.6 times higher than that of bulk g-C3N4 (239 μmol h−1 g−1) owing to the synergistic promotion function of ultrathin nanoflower-like aerogel and oxygen modification structures. This strategy provides a theoretical basis for the development of highly efficient g-C3N4 photocatalysts via molecular assembly.

Effectively Modulating Oxygen Vacancies in Flower-Like δ-MnO2 Nanostructures for Large Capacity and High-Rate Zinc-Ion Storage

HighlightsThe flower-like δ-MnO2 nanostructures with controlled oxygen vacancies as an extraordinary ZIBs cathode are innovatively developed.The cathode can present large capacity and high-rate zinc-ion storage.DFT analysis substantially unveils the effects of various vacancy concentrations on their electrochemical performances.

Enhanced ZnO-based ETL and nanostructured interface modification for improved perovskite solar cells efficiency

Compared to standard silicon solar cells and other thin film cells, perovskite solar cells (PSCs) can achieve high power conversion efficiency and reduce the production costs. ZnO-based ETL in perovskite solar cells provides a lot of benefits, such as low processing temperature and high mobility. However, the reported instability of perovskite layers placed atop ZnO, resulting in poor device performance, has prevented it from being widely used in perovskite solar cells, though. In this work, an innovative way of insuring device performance and longer-term stability is proposed via the incorporation of a novel efficient process. Herein, a V-doped ZnO/Y-doped TiO2 electron transport bilayer was developed to combine the benefits of strong electron extraction and minimal interfacial recombination. This combined approach of engineering both the improved performance of VZnO as ETL and YTiO2 flower like structures at the interface ETL/Perovskite results in large improvements in the performance of the PSC. V-doped ZnO (VZnO) was introduced into the PSC structure as an ETL, due to its excellent electrical and optical properties, to improve electron extraction efficiency, with a doping amount of 4 at.% of vanadium. The latter has been optimized in our previous study. On the other hand, extrinsically doping TiO2 with an amount of 5 at.% of Yttrium (YTiO2) was utilized to enhance its physicochemical properties. The PSC based on VZnO/YTiO2 bilayer ETL possess the best PCE of 15.1%, compared to 9.4% in the pristine ZnO-based ETL solar cell, with the open-circuit voltage (Voc) of 923 mV, short-circuit photocurrent density (Jsc) of 22 mA cm−2, and fill factor (FF) of 74%. Obtained improvements are ascribed to the suppressed charge recombination via the incorporation of YTiO2 flower-like nanostructures at the interface VZnO/perovskite and the enhanced electron transporting in the resulting ETL bilayer structure.

Controllable synthesis and PL propertiesof ZnO flower-like nanostructures by chemical bath method

Zinc oxide (ZnO) flower-like nanosheets and nanorods were synthesized on a glass substrate with an Al layer by a simple chemical bath method, and their morphology was controlled by adjusting the pH of the solution without the assistance of an additional surfactant. For the 3D nanostructures of the annealed nanosheets, the blue light emission at about 410 nm disappeared, which may be due to the defect of zinc vacancy. The emission of the yellow band at about 550 nm was enhanced, which could have originated from the interstitial oxygen. These results indicate that the concentrations or types of the dominant defects could be changed because of the diffusion of Al substrates during the course of annealing. The as-prepared flower-like nanostructures of nanorods exhibited a high UV emission peak (at about 380 nm). After the samples were annealed, the green emission (at about 500 nm) was also enhanced abnormally, except for the UV emission (at 380 nm), indicating that the crystalline quality could not be improved by annealing for complex nanostructures, except for the top of the structures. Our results present a simple, reproducible, and cost-competitive method to synthesize ZnO three-dimensional flower-like structures and would provide useful information for the fabrication of optoelectronic devices at room temperature.

Facile preparation of Ag flower-like nanostructures and their catalytic properties in the degradation of organic dyes

This investigation successfully synthesized silver flower-like nanostructures using Arctostaphylos pungens Kunth fruit extract. The efficiency of Ag particles was evaluated by analyzing the degradation of methylene blue and rhodamine B. Ultraviolet–visible spectroscopy (UV–Vis), XRD patterns, and scanning electron microscopy (SEM) characterized the synthesis products. SEM observations showed different morphologies appeared between 1 and 15 days during silver ion biosynthesis, with sizes ranging from 350 nm to 1 μm. After 8 days, a new nanostructure appeared, consisting of randomly oriented entangled nanorods. EDS chemical maps confirmed that the nanostructures were composed of silver. X-ray diffraction confirmed that the synthesized silver nanostructure had the typical cubic structure. This morphology showed excellent degradation efficiencies in methylene blue (96%) and rhodamine B (82%), indicating high degradation efficiency.

Electrochemical detection of kynurenic acid in the presence of tryptophan with the carbon paste electrode modified with the flower-like nanostructures of zinc oxide doped with terbium.

With the help of a hydrothermal approach in this study, we could provide flower-like nanostructures (NSs) of zinc oxide (ZnO) doped with Tb (FL-NS Tb3+/ZnO). Then, FL-NS Tb3+/ZnO morphology was investigated by energy-dispersive X-ray spectroscopy (EDX), scanning electron microscopy (SEM), X-ray powder diffraction (XRD), and map analysis. The results revealed higher activity centers and porosity of this nanocomposite, which were followed by acceptable electrochemical function. Hence, it can be utilized for fabricating an electrochemical sensor with an appropriate response for the simultaneous determination of kynurenic acid (KYN) and tryptophan (TRP). However, as compared with the modified carbon paste electrode (FL-NS Tb3+/ZnO/CPE), the bare carbon paste electrode (BCPE) exhibited a weak response toward KYN and TRP but the modified electrode was followed by a high current response for KYN and TRP at a potential 0.35 and 0.809V. Therefore, cyclic voltammetry (CV) was applied in optimal experimental conditions to study the electrochemical behaviors of KYN and TRP over the surface of the proposed modified electrode. Moreover, we used differential pulse voltammetry (DPV) for quantitative measurements. It was found that this new modified electrode linearly ranged from 0.001 to 700.0μM, with detection limits of 0.34nM and 0.22nM for KYN and TRP, respectively. In addition, KYN and TRP in real samples can be analyzed by this sensor, with a recovery of 97.75%-103.6% for the spiked KYN and TRP in real samples.

Fabrication of Ru loaded MgB2 with guar gum hybrid for photocatalytic degradation of crystal violet

Today, dyes/pigment-based materials are confronting a serious issue in harming marine ecology. Annihilate these serious water pollutants using photoactive 2D nanohybrid catalysts showed promising comparativeness over available photocatalysts. In the present work, a facile route to decorate Ruthenium (Ru) on 2D MgB2 flower-like nanostructures was developed via ecofriendly guar gum biopolymer substantial template (MgB2/GG@Ru NFS) and its photocatalytic performance was reported. Synthesis of MgB2@Ru, MgB2/GG@Ru NFS and commercial MgB2, was studied by FTIR, XRD, FE-SEM, EDX, AFM, TEM, UV–vis spectra, and XPS analysis. From the results, the MgB2/GG@Ru NFS exhibited a superior photocatalytic performance (99.7 %) than its precursors MgB2@Ru (79.7 %), and MgB2 (53.7 %), with the degradation efficiency of the crystal violet (CV) within 100 min under visible light irradiation. The proposed photo-catalyst MgB2/GG@Ru NFS showed negligible loss of photocatalytic activity even after five successive cycles, revealing its reusability and enhanced stability due to the network structure. The photocatalytic mechanism for MgB2/GG@Ru NFS was evaluated by trapping experiment of active species, verifying that superoxide (O2−) and electron (e−) contributed significant role in the dye degradation.