Simple Route Research Articles

Computation-Guided Discovery of Diazole Monosubstituted Tetrazines as Optimal Bioorthogonal Tools.

Monosubstituted tetrazines are important bioorthogonal reactive tools due to their rapid ligation with trans-cyclooctene. However, their application is limited by the reactivity-stability paradox in biological environments. In this study, we demonstrated that steric effects are crucial in resolving this paradox through theoretical methods and developed a simple synthetic route to validate our computational findings, leading to the discovery of 1,3-azole-4-yl and 1,2-azole-3-yl monosubstituted tetrazines as superior bioorthogonal tools. These new tetrazines surpass previous tetrazines in terms of high reactivities and elevated stabilities. The most stable tetrazine exhibits a reasonable stability (71% remaining after 24 h incubation in cell culture medium) and an exceptionally high reactivity (k2 > 104 M-1 s-1 toward trans-cyclooctene). Due to its good stability in biological systems, a noncanonical amino acid containing such a tetrazine side chain was genetically encoded into proteins site-specifically via an expanded genetic code. The encoded protein can be efficiently labeled using cyclopropane-fused trans-cyclooctene dyes in living mammalian cells with an ultrafast reaction rate exceeding 107 M-1 s-1, making it one of the fastest protein labeling reactions reported to date. Additionally, we showed its superiority through in vivo reactions in living mice, achieving an efficient local anchoring of proteins. These tetrazines are expected to be optimal bioorthogonal reactive tools within living systems.

In-situ halloysite functionalization of anionic hybrid gels possessing easily implemented site-specific (alkyl)amide and carboxyl groups

Design of functional materials with tunable properties based on anionically-modified copolymer network of poly (N-isopropyl acrylamide-co-methacrylic acid) P(NIPA-co-MA) containing linear polyacrylamide and various amounts of Halloysite nanotubes (Hal) was presented using a facile route of solution casting. The organic/inorganic nanostructures based on thermo-responsive PNIPA were constructed to create hybrid materials via in situ polymerization with different Hal-loading and then used for the removal of cationic methylene blue (MB) dye from aqueous solutions. To achieve the desired mechanical property, the optimum composition of hybrids was determined following a simple and cost-effective synthesis procedure. In situ one-pot polymerization was promoted by semi-IPN formation, following a much simpler route than traditional preparation approaches for stable cross-linked hybrid formation. The swelling of hybrids decreased by 2.9-fold with loading of 5.40 % Hal, confirming the hydrogen bonding interactions between Hal and PAAm/P(NIPA-co-MA) network. The mechanical properties of Hal-doped hybrid gels showed an increase–decrease tendency with increase of Hal-content from 0.80 to 5.40 % (w/v) due to the high aspect ratio of Hal and strong secondary interactions between Hal and PAAm/P(NIPA-co-MA) chains. The effective cross-link density for Hal-doped hybrids was expressed by a cubic polynomial as a function of Hal concentration. Temperature-sensitive swelling results showed that the advantage of sustained release property of Hal can be combined with excellent controllability of PNIPA-based network. Adsorption results of MB onto Hal-doped hybrids bearing methacrylic acid moieties demonstrated their potential as efficient adsorbents for the removal of cationic dyes. A new route offered by the proposed procedure for design of hybrids containing “green” one-dimensional nanofillers creates an innovative perspective on robust hybrid structures for practical applications.

Pore-Free Single-Crystalline Particles for Durable Na-Ion Battery Cathodes.

The O3-type Na[Ni1-x-yCoxMny]O2 cathodes have received significant attention in sodium-ion batteries (SIBs) due to their high energy density. However, challenges such as structural instability and interfacial instability against an electrolyte solution limit their practical use in SIBs. In this study, the single-crystalline O3-type Na[Ni0.6Co0.2Mn0.2]O2 (SC-NCM) cathode has been designed and synthesized to effectively relieve the degradation pathways of the polycrystalline O3-type Na[Ni0.6Co0.2Mn0.2]O2 (PC-NCM) cathode for SIBs. The mechanically robust SC-NCM due to the absence of pores in the particles enhances tolerance to particle cracking, resulting in stable cycling performance with a cycle retention of 73% over 350 cycles. Moreover, the proposed SC-NCM is synthesized using a simple and cost-effective molten-salt synthetic route without the complex quenching process typically associated with PC-NCM synthesis methods, showing good practical applicability. This study will provide an innovative direction for the development of advanced cathode materials for practical SIBs.

Emulsion liquid membrane pertraction of soap from crude biodiesel using activated carbon and glycol based deep eutectic solvents

Soap removal from crude biodiesel is considered as one of the most challenging biorefinery processes. This study reports a new technique for soap removal incorporating activated carbon (AC) in an emulsion liquid membrane (ELM) system based on deep eutectic solvents (DES-AC-ELM). These DESs were prepared from two salts, namely tetramethylammonium chloride (TMAC) and choline chloride (ChCl), with different hydrogen bond donors (HBDs) such as ethylene glycol (EG), diethylene glycol (DEG) and triethylene glycol (TEG). COSMO-RS modelling was performed in the evaluation of the activity coefficients and capacity at infinite dilution of DESs. The COSMO-RS simulation shows that the DESs with TEG as the HBD are the most effective stripping agents for soap removal which is in accordance with the experimental results. In addition, the σ-profile and σ-potential were used to investigate the interactions between the soap molecules in each phase. The impact of various process parameters on the soap removal such as the salt: HBD ratio, DES:biodiesel ratio, span-20 concentration, mixing speed, extraction time and dosage of AC were evaluated. The proposed technique achieved a soap extraction efficiency of 99.1% (6.856 ppm) and 97.5% (18.773 ppm) for TMAC:TEG(DES3) and ChCl:TEG(DES6), respectively, with a salt: HBD molar ratio of 1:4, DES:biodiesel ratio of 1:1, 2 wt% surfactant concentration, 10 min extraction duration, 400 rpm mixing speed, 0.5 treatment ratio and 0.5 wt% AC dosage. The transport mechanism of soap conforms to a first-order mass transfer behaviour, with a kinetic rate constant of 0.64 min−1 and 0.43 min−1, for DES3 and DES6, respectively. This study illustrated a new cleaner and simple route for purification of crude biodiesel.

Solution-processed NiS thin films: structural, morphological, compositional and optical analysis

Abstract The present work elucidates a study on the synthesis and characterization of nanostructured NiS thin films, an optical absorber material. NiS films have been deposited on glass substrates using a simple and cost-effective chemical solution route. The deposition process has been accomplished using an aqueous solution of nickel chloride, thiourea, ammonia and Triton. As-deposited and thermally annealed films have been characterized using X-ray diffractometry, Fourier transform infrared spectrometry, scanning electron microscopy, atomic force microscopy, energy dispersive X-ray spectroscopy, and UV–visible spectrometry. It has been observed that the deposited films are nanocrystalline in nature and belong to the rhombohedral structure of the millerite phase. The diffraction peaks become more sharp, discrete and intense whereas the crystallite size increases from 9.89 to 11.78 nm with annealing treatment. Some variations in the infrared peaks have been observed with annealing. The characteristic peak for Ni–S vibration has been observed at ∼604 cm−1. The surface of the films is smooth, uniform, and free from cracks and pinholes. The optical absorbance analysis has confirmed that NiS films possess a direct optical band gap whose values vary from 1.50 to 1.45 eV with annealing.

Simultaneous synthesis of sulfonated reduced graphene oxide@graphene oxide hybrid material for efficient electrochemical sensing of silver ions in drinking water

One of the most important concerns around the world nowadays is the drinking water quality. Silver ions (Ag+) are one of the heavy metal ions that can seriously degrade the water quality and therefore, the human health. Hence, the World Health Organization (WHO) fixed the maximum acceptable concentration of these ions in drinking water at approximately 0.93 µM. Thus, the development of cost-effective and efficient techniques and tools that can help to quantify Ag+ ions in drinking water is of great importance. Herein, we used a new, simple, eco-friendly and low-cost synthesis route to synthesize a sustainable hybrid carbon material, namely sulfonated reduced graphene oxide@graphene oxide (S-rGO@GO) that was utilized as electrode material for Ag+ ions electroanalysis in drinking water. The successful synthesis of S-rGO@GO was evidenced by XRD, Raman spectroscopy, XPS, FE-SEM and EDX. The electrochemical characterization of S-rGO@GO revealed its good affinities towards Ag+ and its good electron transport abilities. The sensor prepared from S-rGO@GO (S-rGO@GO/GCE) showed good repeatability and reproducibility. S-rGO@GO/GCE optimization revealed that its best performance is achieved when 5 µL of 1 mg/mL of S-rGO@GO suspension in ultrapure water is used for its fabrication and when the electrodeposition (Ag+ to Ag0) is carried out at -0.1 V vs. SCE for 200 s. The calibration of S-rGO@GO/GCE exhibited a linear relationship in the concentration range of 0.2 to 1.4 µM, with a sensitivity of (0.605 ± 0.015) µA/µM; the statistic LOD was found to be 0.0007 µM. Furthermore, S-rGO@GO/GCE has shown a great potential for real samples analysis.

Room temperature synthesis of freestanding 2D Mn3O4 nanostructures with enriched electrochemical properties for supercapacitor application

Here we report low temperature growth of two dimensional freestanding nanoplatelets of manganese oxide (Mn3O4) through a simple and cost-effective wet chemical route without the utilization of capping agents. The pristine 2D Mn3O4 nanoplatelets have size and thickness between 100 and 200 nm and 3.5–5.1 nm respectively as corroborated by FESEM, TEM and AFM analysis. The electrochemical performance of the 2D Mn3O4 based electrode is studied using three electrode configuration and 1 M KOH as electrolyte where the remarkably high specific capacitance of 537 F/g (at 2 A g-1) is observed. Moreover, the 2D Mn3O4 based electrode is also found to exhibit an excellent retention of specific capacitance (∼ 93%) up to 5000 cycles. Thus enriched electrochemical performance of 2D Mn3O4 nanoplatelets reveals its potential as electrode material in supercapacitor device applications.

Computational approach to modeling electronic properties of titanium oxynitride systems

The study presents the use of a novel on-lattice sampling approach to generate titanium oxynitride (TiNxOy) structures with potential applications in photovoltaic and water splitting. This approach presents a simple route to overcome challenges with structure-generating tools like Cluster Approach to Statistical Mechanics (CASM), and Ab initio Random Structure Search (AIRSS), CASM faces difficulty in generating ternary structures with large unit cells. With AIRSS, there is an increase in probability of sampling amorphous sample spaces with increased number of atoms in the unit cell. Here an on-lattice sampling approach was used to model the electronic structure of TiNxOy as a function of composition. We present results for Ti2N2O, Ti5N4O4 and Ti7N4O8, with 33 %, 50 % and 67 % N replaced by O via substitution relative to titanium nitride (TiN), respectively. Koopmans theorem was used correct the Kohn-Sham Density Functional Theory (KS-DFT) bandgaps with corresponding values of 2.68 eV, 3.03 eV, and 3.65 eV for 33, 50 and 67 % O doping respectively. The projected density of states (PDOS) plot for TiN shows that the Fermi level is dominated by the 3d atomic orbitals of Ti, confirming pure TiN’s metallicity. The valence bands of TiNxOy structures were dominated by 2p orbitals of O at lower energy levels, but they were dominated by 2p orbitals of N at energies close to the valence band maximum (VBM). The conduction bands were dominated by the 3d atomic orbitals of Ti, with the bandgap increasing with O composition leading to creation of shallow trap states near the VBM, which negatively impacts carrier mobility. In conclusion, the on-lattice sampling approach is an effective tool to generate highly crystalline structures of large unit cells, also keeping O substitution for N below 33 % as seen in Ti2N2O is crucial for avoiding shallow traps in TiNxOy structures.

Surface State-Based panchromatic luminescent carbon dots

Carbon dots have shown a broad application prospect in the fields of sensing and detection, biological imaging, and optoelectronic devices. However, it is still challenging to adopt a simple and green synthesis route and to develop new precursor systems to prepare full-color luminescent carbon dots. This study proposes a mechanism for fine regulation of carbon dot fluorescence spectra based on surface states of CN, COC, and OH, among which CN play a major role in long wavelength emission while COC and OH are responsible for the blue shift of emission wavelength. Using 4,4-bipyridine and p-phenylenediamine as precursors in safe and environmentally friendly glycol and water as solvents for the first time, the fine spectral carbon dots with full spectrum luminescence from purple (441 nm) to red (627 nm) were successfully synthesized by simply changing the composition of the reaction solvent and using a short reaction time. Compared with other reports on regulating polychromatic carbon dots, our method is more refined and has a wider distribution of luminescent colors. In addition, the obtained carbon dots based on such surface state luminescence mechanism have shown good application prospects in specific detection of Fe3+and cell labeling.

Importance of Controlling Cycling Conditions to Improve the Lifetime of Anthraquinone-Based Negolytes with a Potentially Low Cost of Manufacture

Organic redox flow batteries (RFB) in general and anthraquinones in specific have shown a great promise for developing cost-effective alternatives to vanadium RFBs. Two main hurdles, however, have been the fast fade rate and a high estimated cost of manufacture (COM) that have slowed down the scale up of organic RFBs. In this study, 1,8-dihydroxy-2,7-dicarboxymethyl-9,10-anthraquinone (1,8-DCDHAQ), 1,5-dihydroxy-2,6-dicarboxymethyl-9,10-anthraquinone (1,5-DCDHAQ) and 1,3,5,7-tetrahydroxyanthraquinone (THAQ) have been explored. These negolytes are expected to have a reasonably low COM due to their simple synthesis route. Additionally, these electroactive species have a low fade rate. Nevertheless, the fade rates are not adequately low for scaleup and commercialization purposes. Therefore, the effect of various factors including the electrolyte flow rate, cutoff voltages, SOC limits, and OH- concentration on the cycling performance have been explored in order to further reduce the fade rate.Our experimental analysis suggests that: (1) the electrolyte flow rate and the extent of mixing in the electrolyte reservoir may lead to inaccurate capacity utilizations and fade rates, (2) increasing the OH- concentration significantly lowers the fade rate and the effect continues even at concentrations higher than 1.0 M, (3) choosing an unnecessarily low discharge cutoff voltage has a detrimental effect on the fade rate of anthraquinones, (4) SOC limit is a very important tool that significantly lowers the fade rate. Through controlling these cycling conditions, the lifetime can be improved by at least a factor of 10. Under properly chosen conditions, the fade rate of 1,5-DCDHAQ and THAQ remains < 0.001%/day (< 0.4%/year). To further verify the effect of the operating conditions, cyclic voltammetry and HPLC techniques were used to identify and/or characterize the side products in the electrolyte. COM of 1,5-DCDHAQ and THAQ at scale are estimated to be 27.99 and 47.44 $/kAh (or 24.13 and 37.95 $/kWh), respectively. 1,8-DCDHAQ and 1,5-DCDHAQ are expected to have a similar COM.Due to the expected low COM for the abovementioned anthraquinones and their very low fade rate under optimum cycling conditions explored in this study, these molecules now present a distinctive prospect for developing and commercializing an affordable and long lifetime organic RFB chemistry.

Investigation of Vanadium-Based Oxide(L1+xV3O8) for Zn-Ion Batteries

Being a champion in the portable electronics world, high-energy density lithium-ion batteries(LIBs) are irreplaceable. Still, the scarcity of Li resources, high cost, and the inclusion of non-aqueous electrolytes make them relatively perilous and inefficient for grid-scale energy storage. Recently, the blooming aqueous Zn-ion batteries (ZIBs) have emerged as one of the pioneers featuring the inherently safe nature of metallic Zn anode and its unique properties.[1] Vanadium-based compounds show fast ion diffusion and excellent reversible capacity because of their rich valence state of V, facile distortion of V-O polyhedra, and tuneable composition, which offers an excellent treasure house. Moreover, the different oxidation states of vanadium allow a higher degree of structural change and greater functional flexibility while incorporating multivalent cations into vanadium-based compounds.[2] The present work focuses on a V-based oxide cathode, i.e., LixV3O8 (x = 1, 1.3, 1.5), named LVO (SG: P21/m, crystal: monoclinic). It was synthesized using V-pentoxide and LiOH precursors through a simple and economical sol-gel route. LVO was further chemically lithiated to the desired stoichiometries (1.3 and 1.5) using LiI in acetonitrile to get Li1.3V3O8 & Li1.5V3O8, to use them as a cathode material for ZIBs. The best-performing cathode, i.e., L1.5VO, showed the reversible capacity of ~150 mAhg-1 at a current rate of 5 Ag-1 for 3500 cycles in 2 M Zn(Otf)2. Moreover, at 1Ag-1, it showed a high capacity of 260 mAhg-1. In operando XRD suggests the overall phase evolution is highly reversible, as indicated by the reversible evolution of the LVO peaks, the underlying charge storage process can be distinguished into two halves. During discharge, those two halves are: 1.6V – 0.8V window representing Zn2+ intercalation and 0.8 – 0.2V window with predominant H+ intercalation. The latter process is evident from the appearance of the triflate based layered double hydroxide byproduct (triflate-LDH) diffraction peaks (marked with asterisk) [3] formed from the reaction of Zn2+, CF3SO2O- (triflate anion), and OH- left behind after H+ insertion. It is safe to say that the Zn2+ intercalation is the dominant process in the high voltage regime where the triflate-LDH peaks do not appear. Even though the transition from Zn2+ to H+ mediated charge storage coincides with a change in the shape of the voltage profile and its slope around 0.8 V, this is likely related to the puckering of the VOx layers as observed for Li+ intercalation in V2O5. In operando Raman suggested an evolution for the peaks which are associated with the V-O-V bending vibrations in the 200-600 cm-1 range. Overall, A detailed examination of this system using ex-situ, in-operando XRD, in-operando Raman spectroscopy, solid state 1H proton NMR, and ABF-STEM imaging will be discussed, which confirmed Zn-ion (de)intercalation in Li1.5VO with a reversible LDH formation. This vanadate can be proposed as a robust cathode for zinc-ion batteries. Reference s : [1] M. Song, et al., Adv. Funct. Mater. 2018, 28,1802564.[2] Y. Zhang et al., Chem. Front. 20 21, 5, 744-762.[3] P. Oberholzer et al., ACS Appl. Mater. Interfaces 2019, 11, 674−682

BiVO4-Decorated Graphite Felt as Highly Efficient Negative Electrode for All-Vanadium Redox Flow Batteries

Recently, discovering high-performance electrocatalytic materials for vanadium redox flow batteries (VRFB) has been one of the most crucial tasks. This paper successfully fabricates low-cost plate-like bismuth vanadate (BiVO4) material through a simple one-step hydrothermal route, employed as an electrocatalyst to adorn the graphite felt (GF) for use as the negative electrode in VRFB. The experimental results show that BiVO4-3h exhibits the optimal electrocatalytic activity and reversibility for the vanadium redox couples among all samples. The energy efficiency of the VRFB cell assembled with BiVO4-decorated GF as the negative electrode is found to be 75.42% at 100 mA cm−2, which is about 10.24% more efficient than that of the cell assembled with heat-treated graphite felt (HT-GF) electrode. The possible reasons for the activity enhancement can be ascribed to the existence of oxygen vacancies in the BiVO4 lattice structure and the relatively high surface area of BiVO4, which provide more active sites for facilitating the vanadium redox reactions. Furthermore, the BiVO4-GF electrode obstructs the competitive irreversible hydrogen evolution reaction on the negative side of the cell, and it also has better wettability. Impressively, BiVO4-GF as the negative electrode shows good stability over 100 cycles.

Visible-Light-Induced Photocatalytic Deoxygenative Benzylation of Quinoxalin-2-(1H)-ones with Carboxylic Acid Anhydrides.

A visible-light-induced photocatalytic deoxygenative benzylation of quinoxalin-2-(1H)-ones is herein described. This novel approach provides a mild, simple, and practical route to 3-benzylquinoxalin-2(1H)-ones from ubiquitous and safe carboxylic acid anhydrides. A wide range of substrates with different substituents were well-tolerated and efficiently transformed to various functionalized 3-benzylquinoxalin-2(1H)-ones with great potential for valuable applications in drug discovery. Mechanistic investigations suggest H2O as a proton source, while hydroxyl-containing quinoxalin-2(1H)-ones may be key intermediates of the photocatalytic deoxygenative process.

Eco-Friendly Green Synthesis of Zinc Oxide Nano/Microparticles Using Aqueous Leaf Extract of Polygonum cognatum Meisn. Plant

The environmentally friendly plant-based green synthesis approach provides a fabulous opportunity to produce versatile zinc oxide powders with multifarious morphology and/or size. In this study, it was mainly aimed at using Polygonum cognatum Meisn. extract to synthesize zinc oxide powder via a simple green synthesis route. For this purpose, zinc nitrate solution was mixed with an aqueous extract of fresh Polygonum cognatum Meisn. plant leaves to obtain a zinc-based precursor, and then zinc oxide powder was synthesized by means of calcination conducted at 400°C for 2 hours in air. Phase, spectroscopic, and microstructural analysis techniques, as well as Rietveld refinement method and Williamson-Hall analysis, were performed to investigate the powder characteristics. It was found that the synthesized high-purity zinc oxide powder had a hexagonal wurtzite crystal structure. Zinc oxide powder was observed to have a particularly large amount of nano-sized equiaxed particles (~25 nm in average diameter) together with micron-sized hourglass-like particles consisting of two hexagonal prisms (each

Synthesis of sildenafil and its derivatives bearing pyrazolo‐pyrimidinones scaffold

AbstractThe pyrazole ring structure is extensively spotted as a pharmacophore and fortify‐cation of the modern organic synthesis toolbox, which demands synthetic tactics to generate its derivatives. Especially, pyrazolo‐pyrimidinones are crucial part to synthesize phosphodiesterase type 5 (PDE5) such as sildenafil and lodenafil. Herein, we report a simple and efficient route for Sildenafil and derivatives from easily available materials.

Phytogenic Cu2OBi2O3ZrO2 nanomaterial for supercapacitor and water splitting: Synthesis, characterization, and energy applications

Copper-based nanocomposites are regarded as sustainable energy materials having tremendous potential for energy storage supercapacitors and energy generation water splitting applications. Herein, a facile Cu-based ternary Cu2OBi2O3ZrO2 nanocomposite is prepared by a sustainable, lower-cost, and simple hydrothermal-based phyto-synthesis route by using Amaranthus Viridis L. amaranthaceae plant (abbreviated as AVL.A). The synthesized AVL.A-Cu2OBi2O3ZrO2 nanocomposite is characterized by powder-X-ray diffraction and FE-Scanning electron microscopy for its phase composition and surface morphology. The electrochemical efficiency of AVL.A-Cu2OBi2O3ZrO2 nanocomposite is investigated for supercapacitors and overall water splitting. The fabricated Cu2OBi2O3ZrO2 nanocomposite-based Nickel foam (NF) electrode shows superior performance with a specific capacitance of 524.5 F/g at 2 mV/s and 400 F/g at 1 A/g. The excellent rate capability is observed at scan rates from 2 mv/s to 300 mV/s and at current densities from 0.5 A/g to 30 A/g for AVL.A-Cu2OBi2O3ZrO2–NF. Furthermore, fabricated AVL.A-Cu2OBi2O3ZrO2–NF shows excellent electrochemical stability with 100% Coulombic efficiency till 5000 charge-discharge cycles. As bifunctional electrocatalyst AVL.A-Cu2OBi2O3ZrO2–NF electrode exhibits 117 mV overpotential at 10 mA/cm2 current density for HER kinetics along with 112 mV/dec Tafel slope values. The same Tafel slope value is also observed for OER measurements. These values of overpotential and Tafel slope for AVL.A-Cu2OBi2O3ZrO2–NF suggest a rapid and efficient electrochemical process of AVL.A-Cu2OBi2O3ZrO2–NF bifunctional electrocatalyst for energy generation. Overall study highly proposed AVL.A-Cu2OBi2O3ZrO2–NF as the potential electrode for energy storage supercapacitor and energy generation overall water splitting.

Modification of nickel foam with nickel phosphate catalyst layer via anodizing for boosting the electrocatalytic urea oxidation and hydrogen evolution reactions

Urea oxidation reaction (UOR) and hydrogen evolution reaction (HER) are the key processes for implementing urinated water electrolysis and hydrogen green production, respectively. This contribution investigates the modification of commercial nickel foam (NF) with a nickel phosphate (NiPO/NF) heterostructure layer via anodizing in phosphate solution at various potentials (5, 10 and 15 V) as a simple and efficient route to boost the urea-assisted water electrolysis and hydrogen production in alkaline medium. The morphology and composition physicochemical characterisation of the phosphate layer exhibit aggregates of crystalline nanoparticles with interstitial mesoporous and macroporous networks with a mole composition ratio of 9.42: 1.0: 8.14 for Ni: P: O respectively. The electrochemical measurements revealed the NiPO/NF anodized at 10 V exhibits a superior electroactive surface area of 255 cm2, a substantially higher urea oxidation current compared to pristine NF, achieving 20 and 500 mA/cm2 at 1.35 and 1.6 V vs. RHE respectively and retained 100 % of activity during the urea electrolysis for more than 3 h. The electrochemical impedance analysis confirmed the alkaline urea oxidation reaction proceeded via indirect (EC) and direct mechanism and the CO2 intermediates adsorption–desorption became the predominant reaction at more positive potential. The NiPO/NF anode employed in an H-shape can deliver up to ±400 mA/cm2 for UOR/HER at a bias potential of 1.85 V and 8-fold (2.0 mmol/min) much higher hydrogen production rate compared to the pristine NF anode (0.25 mmol/min). Combining commercial nickel foam modification via anodizing and alkaline urea electrolysis at ambient conditions offers a unique and innovative solution for both large-scale hydrogen green production as well as remedy of the urinated wastewater for a more sustainable future.

Cobalt germanium hydroxides with asymmetric electron distribution and surface hydroxyl groups for superb catalytic degradation performances

Peroxymonosulfate (PMS)-based advanced oxidation processes (AOPs) are attractive approaches for solving the global problem of water pollution, due to the generation of highly-active reactive oxygen species (ROS). Therefore, highly-efficient PMS activation is crucial for promoting the catalytic degradation of environmental pollutants. Here, bimetallic CoGeO2(OH)2 nanosheets with abundant surface hydroxyl groups (CGH) were synthesized via a simple hydrothermal route for PMS activation and degradation of various organic contaminants for the first time. The abundant surface hydroxyl groups (≡Co–OH/≡Ge–OH) could promptly initiate PMS to generate highly-active species: singlet oxygen (1O2), sulfate radicals (SO4·−) and hydroxyl radicals (HO•), while the asymmetric electron distribution among Co–O–Ge bonds derived from the higher electronegativity of Ge than Co further enhances the quick electron transfer to promote the redox cycle of Co2+/Co3+ and Ge2+/Ge4+, thereby achieving an outstanding catalytic capability. The optimal catalyst exhibits nearly 100 % catalytic degradation performance of dyes (Methylene blue, Rhodamine B, Methyl orange, Orange II, Methyl green) and antibiotics (Norfloxacin, Bisphenol A, Tetracycline) over a wide pH range of 3–11 and under different coexisting anion conditions (Cl−, HCO3–, NO3–, HA), suggesting the excellent adaptability for practical usage. This study could potentially lead to novel perspectives on the remediation of water areas such as groundwater and deep-water areas.

Precise Construction of Chiral Plasmonic Nanoparticles for Enantioselective Discrimination.

Chiral plasmonic nanostructures exhibit potential in the advanced manufacturing industry, due to their fascinating characteristics. However, the limitation of existing fabrication methods as difficulty to precisely manipulate chiral nanostructures at the nanoscale restricts their application and optimization of performance. In this work, we report a simple and robust route for the precise construction of chiral Au nanoparticles (NPs), employing star-like block copolymers with well-defined structures as chiral templates. The globular unimolecular micelles as nanoreactors enabled control over the size, shape, and chirality of in situ grown nanocrystals. Utilizing the chiral anisotropy property of surface-enhanced Raman scattering (SERS), the enantioselective discrimination on various substrates was accomplished with an enhancement factor over 9.3 × 106. NPs with a smaller size exhibited strengthened Raman enhancement and chiral recognition. Furthermore, these chiral unimolecular-micelle-based templates with high efficiency and strong controllability could pave the way for tailor-made chiral nanomaterials.

Sono-synthesis and characterization of next-generation antimicrobial ZnO/TiO2 and Fe3O4/TiO2 bi-nanocomposites, for antibacterial and antifungal applications

Ultrasonic-assisted synthesis of ZnO/TiO₂ and Fe₃O₄/TiO₂ bi-oxide nanocomposites at low frequencies (60 kHz) with their characterizations and antibacterial/antifungal applications are investigated in this study. Using nanotechnology as the next-generation solution, this research explored the potential of metal oxide nanoparticles as effective antibacterial agents. Nanomaterials were synthesized via a novel and facile method (sono-synthesis) and characterized using various techniques (XRD, SEM, FTIR, zeta potential analysis, Raman spectroscopy, and XPS), revealing nanoscale sizes of 25 nm for ZnO/TiO₂ and 31 nm for Fe₃O₄/TiO₂. Structural analysis demonstrated the distinct crystalline phases of the synthesized nanomaterials: TiO₂ with anatase structure (25 %), hexagonal wurtzite structure for ZnO, and Fe₃O₄ with inverse spinel structure, formed in nano-dimensions (19–31 nm) with a near-spherical shape. Antibacterial and antifungal assays highlighted the efficacy of both bi-nanocomposites against gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli and Pseudomonas aeruginosa) bacteria, along with their potent activity against Candida albicans and non-albicans Candida. Moreover, principal component analysis (PCA) was used to identify potential relationships between the physicochemical properties (zeta potential, size, conductivity, and concentration) of all nanomaterials tested and their zone of inhibition (ZOI) against all bacterial species tested. Overall, this study emphasizes the novelty of employing a simple and efficient sono-synthetic route to synthesize ZnO/TiO₂ and Fe₃O₄/TiO₂ bi-nanocomposites and investigate their significant antibacterial and antifungal activities. Additionally, it identifies the potential relationships between the physicochemical properties of the nanomaterials tested and their antimicrobial activity. This approach provides a robust framework for future applications of bi-nanocomposites in combating microbial infections.