Facile One-pot Hydrothermal Synthesis Research Articles

Fabrication of iron manganese oxide-reduced graphene oxide nanocomposite: A highly effective synergistic electrocatalyst for sensitive metronidazole detection

Efficient 2D-inorganic spinel perovskites nanostructure materials are used as potential candidates for highly sensitive detection of harmful substances present in the environment. In this regard, a facile one-pot hydrothermal synthesis was employed to fabricate nanocomposite material containing iron manganese oxide (FeMn2O4) decorated with reduced graphene oxide (rGO) which is used as an electrochemical detection of metronidazole (MTZ). The crystalline nature and structural insights of the as-synthesized FeMn2O4-rGO nanocomposite were established using various spectroscopic and electrochemical techniques. Distinctively FeMn2O4-rGO nanocomposite fashioned glassy carbon electrode (GCE) showed excellent linear range (0.01–512.2 μM), sensitivity (71.4 μA mM−1 cm−2), limit of detection (0.0129 μM), reproducibility, stability and resist-interference capability towards metronidazole (MTZ) antibiotic drug. In addition, the fabricated FeMn2O4-rGO/GCE electrochemical sensor exhibited a remarkable MTZ detection in spiked water as well as urine samples with better recovery percentages supporting its facile and feasible nature for environmental applications. The present work established the fabrication of FeMn2O4-rGO/GCE nanocomposite for effective determination of antibiotic drugs in real sample analysis.

Towards an agglomeration free Ca(OH)2/CaO thermochemical energy storage loop via nanofabricated hollow CaO microspheres with highly porous shells

The Ca(OH)₂/CaO loop offers a promising solution for seasonal thermochemical heat storage, vital for decarbonizing the heating sector thanks to its high energy density and abundant raw materials. However, cyclic hydration/dehydration of limestone-derived CaO (r-CaO) faces challenges like agglomeration and high-volume expansion, limiting its expected performances. This study focuses on fabricating hollow CaO microspheres (h-CaO) with porous shells via a facile one-pot hydrothermal synthesis method, without doping materials. These microspheres exhibit superior cyclic performance compared to r-CaO, with SEM-EDS confirming successful fabrication. Over 30 cycles in the temperature range of 400–550 °C, h-CaO achieves an average storage density of 1755 kJ/kg, peaking at 1835 kJ/kg, with kinetics twice as high as r-CaO. Most importantly, the hollow microstructure reduces dramatically the apparent volumetric expansion from 250 % to as little as 32 %, offering a potential solution to agglomeration at the reactor level and advan44cing the commercial viability of the Ca(OH)2/CaO thermochemical storage technology.

Pyridine-Regulated Lamellar Nickel-Based Metal-Organic Framework (Ni-MOF) for Nonenzymatic Electrochemical Glucose Sensor.

2D metal-organic frameworks (MOFs) are considered as promising electrochemical sensing materials and have attracted a lot of attention in recent years. Compared with bulk MOFs, the construction of 2D MOFs can increase the exposure of active sites by obtaining a larger surface area ratio. Herein, a facile one-pot hydrothermal synthesis of pyridine-regulated lamellar Ni-MOFs with ultrathin and well-defined 2D morphology is described. Compared with the bulk structure, the 2D lamellar Ni-MOF has higher surface area and active site density, showing better electrochemical glucose sensing performance. The 2D lamellar Ni-MOF exhibits a fast amperometric response of less than 3 s and a high sensitivity of 907.54µA mm-1 cm-2 toward glucose with a wide linear range of 0.5-2665.5 µm. Furthermore, the 2D lamellar Ni-MOF also possesses excellent stability and reproducibility, and can be used to detect glucose with high accuracy and reliability in different environments.

Facile one-pot hydrothermal synthesis of reticulated porous tobermorite for fast phosphorus recovery

Phosphorus, a depletable resource in nature, has been constantly consumed. Its recovery still remains difficult to be solved. Tobermorite (Ca5Si6O16(OH)2) with chemical stability is an efficient adsorbent for phosphorus. Herein, the reticulated porous tobermorite (CSH) was successfully synthesized through a facile one-step hydrothermal process and its adsorption performance for phosphorus was evaluated. The adsorption reached the equilibrium within 5 min. The kinetic study demonstrated that the adsorption followed the pseudo-second-order model, indicating the adsorption involved the chemisorption. The adsorption perfectly fitted the Langmuir isotherm. The calculated maximum adsorption capacity is 152.46 mg·g−1 at room temperature. Its excellent adsorption performance for phosphorus is attributed to its reticulated porous structure and larger specific surface area. The adsorption is mainly affected by the electrostatic interaction and the releasing ability of OH- and Ca2+ from the CSH. Reticulated porous CSH is a potential efficient adsorbent for phosphorus recovery owing to its facile synthesis, fast adsorption rate, high adsorption capacity and excellent reusability, which provide a feasible alternative for phosphorus recovery.

Facile one-pot hydrothermal synthesis of a zinc oxide/curcumin nanocomposite with enhanced toxic activity against breast cancer cells.

Zinc oxide/Curcumin (Zn(CUR)O) nanocomposites were prepared via hydrothermal treatment of Zn(NO3)2 in the presence of hexamethylenetetramine as a stabilizing agent and CUR as a bioactive element. Three ZnO : CUR ratios were investigated, namely 57 : 43 (Zn(CUR)O-A), 60 : 40 (Zn(CUR)O-B) and 81 : 19 (Zn(CUR)O-C), as assessed by thermogravimetric analyses, with an average hydrodynamic diameter of nanoaggregates in the range of 223 to 361 nm. The interaction of CUR with ZnO via hydroxyl and ketoenol groups (as proved by X-ray photoelectron spectroscopy analyses) was found to significantly modify the key properties of ZnO nanoparticles with the obtainment of a bilobed shape (as shown by scanning electron microscopy), and influenced the growth process of the composite nanoparticles as indicated by the varying particle sizes determined by powder X-ray diffraction. The efficacy of Zn(CUR)O as anticancer agents was evaluated on MCF-7 and MDA-MB-231 cancer cells, obtaining a synergistic activity with a cell viability depending on the CUR amount within the nanocomposite. Finally, the determination of reactive oxygen species production in the presence of Zn(CUR)O was used as a preliminary evaluation of the mechanism of action of the nanocomposites.

CuCoO2/CuO heterostructure: understanding the role of band alignment in selective catalysis for overall water splitting

Employing a facile one-pot hydrothermal synthesis approach, in this work, we achieved the successful synthesis of a CuCoO2/CuO heterostructure, which was characterized by an atomic-scale intimately bonded interface.

Facile One-Pot Hydrothermal Synthesis of Hierarchical MoS2/α-MnS Nanocomposites with Good Cycling Performance as Anode Materials for Lithium-Ion Batteries

The design of nanoscale composites with a hierarchical structure can improve the poor cycling performances of transition metal sulfides such as anode materials. The hierarchical MoS2/α-MnS nanocomposites were synthesized by a facile one-pot hydrothermal method in this study, aiming to improve the cycling performance. As an anode material, hierarchical MoS2/α-MnS nanocomposites deliver a high reversible capacity, of 1498 mAh g−1 at a current density of 50 mA g−1; a capacity of ~800 mAh g−1 is maintained over 100 cycles at 300 mA g−1, and a capacity of 907 mAh g−1 is obtained at 1200 mA g−1. Moreover, these capacities increase with the number of cycles, which is mainly owed to the occurring metallic nanoparticles that catalyze the developing polymeric film and enhance the conductivity of the active materials during the electrochemical reactions. The good cycling performances are attributed to the synergistic effects between MoS2 and α-MnS.

Hydrothermal synthesis of rGO-MnO2 nanocomposite: Characterization and in vitro biological evaluation

In today’s scenario, a number of nanocomposites are evidencing handy control in in vitro biological studies like anti-inflammatory and antidiabetic activity. Since the nanocomposite action and mechanism are totally different from others, like simple moleculesof antibiotics. This work described a facile one-pot hydrothermal synthesis of the rGO-MnO2 nanocomposite. The prepared samples were characterized and confirmed by XRD, UV, SEM, EDX, and XPS studies. Furthermore, the catalytic performance evolved through in vitro biological applications such as anti-inflammatory and antidiabetic activities. rGO-MnO2 nanocomposite has more biological activity than pure MnO2 nanoparticles, as demonstrated by the results.

Calcium Silicate Hydrate Cation-Exchanger from Paper Recycling Ash and Waste Container Glass

Synthetic 11 Å tobermorite (Ca5Si6O16(OH)2.4H2O) and its Al-substituted analogue are layer-lattice ion-exchangers with potential applications in nuclear and hazardous wastewater treatment. The present study reports the facile one-pot hydrothermal synthesis of an Al-tobermorite-rich cation-exchanger from a combination of paper recycling ash, post-consumer container glass, and lime, with compositional ratios of [Ca]/[Si + Al] = 0.81 and [Al]/[Si + Al] = 0.18. The reaction products were characterized by powder X-ray diffraction analysis, 29Si magic angle spinning nuclear magnetic resonance spectroscopy, and scanning electron microscopy. Hydrothermal processing in 4 M NaOH(aq) at 100 °C for 7 days yielded an Al-tobermorite-rich product that also contained katoite (Ca3Al2SiO12H8), portlandite (Ca(OH)2), calcite (CaCO3), and amorphous silicate gel. The hydrothermal product was found to have a Cs+ cation exchange capacity of 59 ± 4 meq 100 g−1 and selective Cs+ distribution coefficients (Kd) of 574 ± 13 and 658 ± 34 cm3 g−1 from solutions with molar ratios [Cs+]:[Na+] and [Cs+]:[Ca2+] of 1:100. In a batch sorption study at 20 °C, the uptakes of Pb2+, Cd2+, and Cs+ were determined to be 1.78 ± 0.04, 0.65 ± 0.06, and 0.36 ± 0.03 mmol g−1, respectively. The kinetics of Pb2+, Cd2+, and Cs+ removal were described by the pseudo-second-order rate model, which gave respective rate constants (k2) of 0.010, 0.027, and 1.635 g mmol−1 min−1, and corresponding correlation coefficients (R2) of 0.997, 0.996, and 0.999. The metal ion sorption properties of the tobermorite-rich product compared favorably with those of other waste-derived tobermorites reported in the literature. Potential strategies to improve the yield, crystallinity, and sorption characteristics of the product are discussed.

Regulating the surface of anion-doped TiO2 nanorods by hydrogen annealing for superior photoelectrochemical water oxidation

Dedications to achieve the highly efficient metal oxide semiconductor for the photoelectrochemical water splitting system have been persisted to utilize the TiO2 as the promising photoanode material. Herein, we report notable progress for nanostructured TiO2 photoanodes using facile sequential one-pot hydrothermal synthesis and annealing in hydrogen. A photocurrent density of 3.04 mA·cm−2 at 1.23 V vs. reversible hydrogen electrode was achieved in TiO2 nanorod arrays annealed in hydrogen ambient, which is approximately 4.25 times higher than that of pristine TiO2 annealed in ambient air. 79.2% of incident photon-to-current efficiency at 380 nm wavelength demonstrates the prominence of the material at the near-UV spectral range region and 100 h chronoamperometric test exhibits the stability of the photoanode. Detailed studies regarding crystallinity, bandgap, and elemental analysis provide the importance of the optimized annealing condition for the TiO2-based photoanodes. Water contact angle measurement displays the effect of hydrogen annealing on the hydrophilicity of the material. This study clearly demonstrates the marked improvement using the optimized hydrogen annealing, providing the promising methodologies for eco-friendly mass production of water splitting photoelectrodes.Graphical

A facile one-pot hydrothermal synthesis of cobalt sulfide nanospheres integrated with graphene nanocomposite as electrode material for high-performance supercapacitors

A facile one-pot hydrothermal synthesis of cobalt sulfide nanospheres integrated with graphene nanocomposite as electrode material for high-performance supercapacitors

One-pot synthesis of BiSbO4/BiOBr nanocomposite with excellent UV-photocatalytic activity

A facile one-pot hydrothermal synthesis procedure and UV-photocatalytic activity of a series of BiSbO4/BiOBr nanocomposites with various BiSbO4-rich contents were first-time reported in this work. The results showed that BiSbO4/BiOBr nanocomposites containing 10-nm BiOBr nanocubes embedded on BiSbO4 nanobundles were obtained readily. For the optimized BiSbO4/BiOBr nanocomposite, the methyl orange photocatalytic removal efficiency under 365-nm UV illumination was 90% after 120 min, pronouncedly higher than that of the pure BiSbO4 sample (22%). A heterogeneous phase junction formed between BiSbO4 nanobundles and embedded BiOBr nanocubes was supposed to be a major factor causing this enhanced photocatalytic activity of the optimized nanocomposite sample. The mechanism of methyl orange photodegradation over BiSbO4/BiOBr nanocomposites containing heterogeneous phase junction was also proposed.

The effect of potassium chloride on BiVO4 morphology and photocatalysis

The monoclinic BiVO4 was synthesized via a facile one-pot hydrothermal synthesis. KCl concentration in the precursor greatly influences the crystal growth, morphology, and absorption properties of BiVO4 attributed to the effect of Clˉ ions on the formation of BiOCl intermediate and preferential growth of BiVO4 crystals along {010} planes. The photocatalytic property of BiVO4 is accordingly altered based on the KCl content. The “shuriken-like” BiVO4 prepared with 3 ​mmol of KCl exhibits the highest photocatalytic activity among our samples. Its photocatalytic rhodamine B degradation efficiency could reach 94.7% after 4 ​h of visible-light irradiation. The degradation efficiency only decreased to 90.8% after four runs of 4 h irradiation. The photodegradation rate with the shuriken-like BiVO4 is around 2.3 times higher than that with the rod-like BiVO4 prepared without KCl, owing to its highest relative intensity ratio of (040) to (1¯21) plane, which maximizes the exposed active {010} facets of BiVO4.

One-pot in situ synthesis of Cu-SAPO-34/SiC catalytic membrane with enhanced binding strength and chemical resistance for combined removal of NO and dust

The SiC catalytic membrane combining dust removal and denitration can realize the efficacious treatment of atmospheric pollutants. Unfortunately, a large amount of SiO2, formed by the partial oxidation of SiC at a high temperature, results in the decreased chemical resistance of SiC catalytic membrane. In addition, the complicated preparation processes and susceptible to loss of catalytic components under harsh conditions restrict the industrial application of SiC catalytic membranes. Here, the Cu-SAPO-34(D)/SiC catalytic membranes were directly prepared via a facile one-pot hydrothermal synthesis method, which ingeniously utilized the generated SiO2 as a Si source to participate in the growth of Cu-SAPO-34 zeolites. Excellent binding strength and chemical resistance were simultaneously realized for the SiC catalytic membranes. As a comparison, a Cu-SAPO-34(I)/SiC catalytic membrane was fabricated via the conventional two-step ion-exchange method. The 0.2 Cu-SAPO-34(D)/SiC (Cu molar ratio of 0.2) achieved the best NH3-SCR performance among the prepared catalytic membranes for its highly active copper and oxygen species, abundant Lewis acid sites and remarkable redox capacity. When implementing the simultaneous removal of NO and PM, the 0.2 Cu-SAPO-34(D)/SiC catalytic membrane achieved a high NO degradation performance of 98% from 200 to 280 °C, coupled with an excellent PM0.3 (model dust with average size of 300 nm) filtration performance of 99.99%. These results were better than those of the Cu-SAPO-34(I)/SiC catalytic membrane (92% for NO degradation and 99.98% for PM0.3 filtration). The one-pot in situ synthesis of Cu-SAPO-34(D)/SiC catalytic membrane with enhanced binding strength and chemical resistance provides a novel strategy for preparation of high-performance SiC catalytic membrane with double benefits.

Pd/Mg(OH)2 Heterogeneous Nanocatalysts Synthesized by a Facile One-Pot Hydrothermal Method for CO Direct Esterification to Dimethyl Oxalate

Pd-based heterogeneous nanocatalysts have wide application in chemical industry. However, the traditional synthesis process contains multi-steps such as impregnation, dry, calcination and reduction. The pre-synthesis nanoparticles process can reduce the steps, but need to remove the surfactants, which are added in the synthesis process. In this work, a facile one-pot hydrothermal synthesis process named as single molecular precursor method was successfully developed to prepare Pd/Mg(OH)2 heterogeneous nanocatalysts with clean surface. The as-synthesized Pd/Mg(OH)2 heterogeneous nanocatalysts show excellent performance for CO direct esterification to dimethyl oxalate (DMO). The WTY (weight time yield) of DMO can reach the high-performance of 2544 g kgcat.−1 h−1, while the conversion of CO is 62.6% and selectivity to DMO is 90.8%. The single molecular precursor method developed by this work can be extended to other supported noble metal nanocatalysts.

PH-Responsive Torpedo-Like Persistent Luminescence Nanoparticles for Autofluorescence-Free Biosensing and High-Level Information Encryption.

Persistent luminescent nanoparticles (PLNPs) with intrinsic stimuli-responsive properties are desirable because of no autofluorescence background and natural responsive luminescence. However, the stimuli-responsive features of pure PLNPs have been unexplored. Here we show a facile one-pot hydrothermal synthesis of green-emitting Zn2 GeO4 :Mn2+ ,Pr3+ nanoparticles (ZGMP) with regular shape, uniform size and good afterglow luminescent performance. We also report the pH stimuli-responsive luminescent behavior of ZGMP and its possible mechanism. Taking the intriguing feature of pH responsive persistent luminescence, we explore ZGMP as autofluorescence-free probes to achieve stimuli-activated signal switch for biosensing by integrating enzyme catalysis reaction mediated pH modulation. The pH-responsive persistent luminescence also makes ZGMP promising for high-level information encryption.

Indium-Doped Rutile Titanium Oxides As Anode Materials for Na-Ion Batteries

Na-ion batteries (NIBs) have been recently considered as an attractive alternative to Li-ion batteries (LIBs) for large-sized rechargeable batteries because Na’s resource has a lower cost and a wider availability compared to Li’s resource. Na+ has a 2.4 times larger ionic volume than Li+, resulting in slower kinetics of its host materials of negative electrode (anodes). We have recently developed various compounds as novel anode materials of NIB [1-6], and have particularly focused on rutile-type TiO2 with very favorable ion-diffusion path along its c-axis. However, rutile TiO2 has two problems as anode materials: the very low diffusion coefficient along ab in-plane direction and the poor electronic conductivity.To address the issues, the authors have conducted two kinds of approaches: the doping of impurity elements into the crystal structure [1] and the improvement in the crystallinity of TiO2 particles [2]. The approaches could improve the electronic conductivity and the trapping at grain boundaries, leading to a remarkable enhancement in the anode performances. In particular, the Nb-doped TiO2 electrode [6] and Ta-doped TiO2 electrode [5] showed remarkably-enhanced anode performances. Nevertheless, there still remains a serious problem that the capacity steeply increases or decreases in the initial several tens of cycles even by Nb-doping and Ta-doping. The dopings of Nb and Ta have another effect of expanding crystal lattice of rutile TiO2 because the sites of Ti4+ (ionic diameter: 121 pm) are substituted with Nb5+ (128 pm) and Ta5+ (128 pm). This expansion is accompanied by an increase in size of Na+ diffusion path, which is favorable for improving the Na+ insertion−extraction properties. Since the ionic diameter of Na+ (204 pm) is larger than that of Li+ (152 pm), the size expansion of ion diffusion path is more important for NIB compared with LIB.Indium (In) has a much larger ionic size of 160 pm than Nb and Ta. It is thus expected that the larger size will change the doping effects on Na+ insertion−extraction properties. In the previous study, the authors have not systematically investigated the dependence of In doping amount on the anode properties. Therefore, in this study, we evaluated the anode properties of In-doped rutile electrodes with various doping amounts to clarify the influence of In doping. In addition to this, we used an anionic surfactant for the hydrothermal synthesis of TiO2 to reduce its particle length [6].We prepared In-doped rutile TiO2 by a facile one-pot hydrothermal synthesis [6-8]. For the reduction of the particle length, we used a solution of the anionic surfactant (Sodium dodecyl sulfate: SDS) for the synthesis. We investigated the influences of In doping and the particle morphology on the Na+ storage properties. The X-ray diffraction analyses revealed that the solid solubility limit was found to be 0.8 at.% in In-doped TiO2. With increasing the In amount from to 0.8 at.%, the lattice parameters of rutile TiO2 were increased, indicating the expansion of diffusion path size for Na+. The degree of size expansion by In doping is comparable to the change by 6 at.% of Nb doping. The remarkable feature is that the similar size increasing can be achieved even with a much smaller doping amount in the case of In doping because of its larger ionic size. The improvement in the electronic conductivity was also confirmed by 0.8 at.% In doping into TiO2.In the case where no surfactant was used, the best anode performance was obtained for 0.8 at.%. In-doped TiO2 electrode by the benefits of three doping effects: (i) expanded diffusion-path size, (ii) improved electronic conductivity, and (iii) reduced electron charge density in the path. A further enhancement in the performance was achieved for the In-doped TiO2 with a reduced particle-length by the synthesis in the SDS surfactant solution. This electrode exhibited a better cycle stability, and maintained high discharge capacities of 240 mA h g−1 for 200 cycles. The reason is probably that Na+ can be inserted in the inner part of TiO2 particles because of its reduced particle-length.

One-pot synthesis of hierarchical CdS/MoS2/rGO with enhanced (photo)electrocatalytic activities

A facile one-pot hydrothermal synthesis of 3D windmill-like CdS/MoS2/rGO has been reported. The MoS2/rGO framework prevents the aggregation of CdS and leads to a two-pathway for electron transfer, thus enhancing the electron density and more active site on the rGO surface. Compared with pure CdS, the hierarchical CdS/MoS2/rGO catalyst displays superior photocatalytic H2 production activity and electrocatalytic H2 evolution overpotential, which is 3.5 times in photoactivity and 146.7 mV decrease of overpotential. A new hierarchical structure and its characteristics and mechanism are proposed at the atomic-/nanoscale.

Simultaneous formation of Bi2O2(OH)(NO3)/BiOBr ultrathin hierarchical microspheres for effectively promoting visible-light-driven photocatalytic activity in environmental remediation

As a two-dimensional nanomaterial, bismuth oxybromide (BiOBr) have attracted tremendous interest in the area of visible-light photocatalysis since it can provide the internal electric field (IEF) through z-axis through its unique electronic band structure. However, the insufficient active sites and rapid recombination rate of charged carriers hamper the efficiency of the photocatalysis. To address these two major obstacles, an enticing strategy of constructing heterojunction was established by introducing Bi2O2(OH)(NO3) (BiON) in BiOBr with the same precursor. Through a facile one-pot hydrothermal synthesis, two Sillén-type layered photocatalysts, with intimately constructed ultrathin heterostructure, was synthesized by the co-precipitation method. In this work, the formation of Bismuth-based heterojunction for charge separation is established by the excessive bismuth nitrate, which subsequently participates with the in situ growth of ultrathin hierarchical microspheres. By attenuating the thickness of BiOBr from 20 nm to 8 nm with the aid of BiON, the photogenerated charges could migrate to the active sites through shorter charge diffusion pathway. Also, the BiOBr and BiON act as an active bridge to promote the separation of electron-hole pairs, which also brings out more active sites due to its increased specific surface area. BiON/BiOBr ultrathin hierarchical microspheres exhibited enhanced visible-light photocatalytic activity for decontaminating several types of pollutants. Besides, the activity of as-prepared BiON/BiOBr was further evaluated by inhibiting the growth of kanamycin-resistant bacteria strains. This study presents a novel strategy to incorporate the crystalline bismuth hydrate nitrate into BiOBr to form ultrathin hierarchical microspheres with high surface area for environmental remediation.

Multi-Functional Carbon Dots from an Ayurvedic Medicinal Plant for Cancer Cell Bioimaging Applications.

The combination of an Ayurvedic wisdom and nanotechnology may help us to resolve the complex healthcare challenges. A facile and economical one-pot hydrothermal synthesis method has been adopted for preparing a blue fluorescent carbon dots (CDs) with a quantum yield of 15.10% from an Ayurvedic medicinal plant Andrographis paniculata (AP). The Andrographis paniculata derived CDs (AAPCDs) were then characterized using different techniques. Through High Performance Thin Layer Chromatography (HPTLC) profiling of the AP extract and the CDs, it was found that some of the phytoconstituents are retained as such while others may have been converted into their derivatives during the process of formation of CDs. The CDs are designed to possess cellular imaging of human breast carcinoma cells (MCF-7), apart from free radicals sensing and scavenging capabilities. AAPCDs showed minimal cytotoxicity in Multi Drug Resistant clinically isolated strains of gram positive and gram negative bacteria which may be employed for microbiology oriented experiments. These results suggest potential of multi-functional AAPCDs as nano-probes for various pharmaceutical, biomedical and bioengineering applications.