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1.
ACS Omega ; 9(14): 16334-16345, 2024 Apr 09.
Article in English | MEDLINE | ID: mdl-38617612

ABSTRACT

The growing concerns about environmental pollution, particularly water pollution, are causing an increasing alarm in modern society. One promising approach to address this issue involves engineering existing materials to enhance their effectiveness. A one-step solvothermal reconstruction approach was used to build an eco-friendly two-dimensional (2D) AlNiZn-LDH/BDC MOF composite. The characterizations confirm the formation of a metal-organic framework (MOF) at the layered double hydroxide (LDH) surface. The resulting synthesized material, 2D AlNiZn-LDH/BDC MOF, demonstrated remarkable efficacy in decontaminating methylene blue (MB), a model cationic dye found in water systems. The removal performance of 2D AlNiZn-LDH/BDC MOF was significantly higher than that of pristine 2D AlNiZn-LDH. This improvement shows the potential to increase the adsorption capabilities of nanoporous LDH materials by incorporating organic ligands and integrating meso-/microporosity through MOF formation on their surfaces. Furthermore, their kinetic, isothermal, and thermodynamic studies elucidated the adsorption behavior of this composite material. The results of synthesized MOF showed excellent removal efficiency (92.27%) of 10 ppm of MB aqueous solution as compared to pristine LDH. Additionally, the as-synthesized adsorbent could be regenerated for six successive cycles. This method holds promise for the synthesis of novel and highly effective materials to combat water pollution, laying the groundwork for potential advancements in diverse applications.

2.
Chem Asian J ; : e202301051, 2024 Jan 12.
Article in English | MEDLINE | ID: mdl-38216532

ABSTRACT

Enhanced electrocatalysts that are cost-effective, durable, and derived from abundant resources are imperative for developing efficient and sustainable electrochemical water-splitting systems to produce hydrogen. Therefore, the design and development of non-noble-based catalysts with more environmentally sustainable alternatives in efficient alkaline electrolyzers are important. This work reports ferrocene (Fc)-incorporated nickel sulfide nanostructured electrocatalysts (Fc-NiS) using a one-step facile solvothermal method for water-splitting reactions. Fc-NiS exhibited exceptional electrocatalytic activity under highly alkaline conditions, evident from its peak current density of 345 mA cm-2 , surpassing the 153 mA cm-2 achieved by the pristine nickel sulfide (NiS) catalysts. Introducing ferrocene enhances electrical conductivity and facilitates charge transfer during water-splitting reactions, owing to the inclusion of iron metal. Fc-NiS exhibits a very small overpotential of 290 mV at 10 mA cm-2 and a Tafel slope of 50.46 mV dec-1 , indicating its superior charge transfer characteristics for the three-electron transfer process involved in water splitting. This outstanding electrocatalytic performance is due to the synergistic effects embedded within the nanoscale architecture of Fc-NiS. Furthermore, the Fc-NiS catalyst also shows a stable response for the water-splitting reactions. It maintains a steady current density with an 87% retention rate for 25 hours of continuous operation, indicating its robustness and potential for prolonged electrolysis processes.

3.
Chem Rec ; 24(1): e202300161, 2024 Jan.
Article in English | MEDLINE | ID: mdl-37582638

ABSTRACT

Due to ever-increasing global energy demands and dwindling resources, there is a growing need to develop materials that can fulfil the World's pressing energy requirements. Electrochemical energy storage devices have gained significant interest due to their exceptional storage properties, where the electrode material is a crucial determinant of device performance. Hence, it is essential to develop 3-D hierarchical materials at low cost with precisely controlled porosity and composition to achieve high energy storage capabilities. After presenting the brief updates on porous carbons (PCs), then this review will focus on the nitrogen (N) doped porous carbon materials (NPC) for electrochemical supercapacitors as the NPCs play a vital role in supercapacitor applications in the field of energy storage. Therefore, this review highlights recent advances in NPCs, including developments in the synthesis of NPCs that have created new methods for controlling their morphology, composition, and pore structure, which can significantly enhance their electrochemical performance. The investigated N-doped materials a wide range of specific surface areas, ranging from 181.5 to 3709 m2 g-1 , signifies a substantial increase in the available electrochemically active surface area, which is crucial for efficient energy storage. Moreover, these materials display notable specific capacitance values, ranging from 58.7 to 754.4 F g-1 , highlighting their remarkable capability to effectively store electrical energy. The outstanding electrochemical performance of these materials is attributed to the synergy between heteroatoms, particularly N, and the carbon framework in N-doped porous carbons. This synergy brings about several beneficial effects including, enhanced pseudo-capacitance, improved electrical conductivity, and increased electrochemically active surface area. As a result, these materials emerge as promising candidates for high-performance supercapacitor electrodes. The challenges and outlook in NPCs for supercapacitor applications are also presented. Overall, this review will provide valuable insights for researchers in electrochemical energy storage and offers a basis for fabricating highly effective and feasible supercapacitor electrodes.

4.
Chem Asian J ; : e202300870, 2023 Nov 09.
Article in English | MEDLINE | ID: mdl-37943100

ABSTRACT

Amorphous inorganic perovskites have attracted significant attention as efficient electrocatalysts due to their unique structural flexibility and good catalytic activity. In particular, the disordered structure and a surface rich in defects such as oxygen vacancies can contribute to the superior electrocatalytic activity of amorphous oxides compared to their crystalline counterpart. In this work, we report the synthesis of LaCoO3 , followed by an amorphization process through urea reduction with tailored modifications. The as-synthesized catalysts were thoroughly tested for their performance in oxygen evolution reaction (OER), Remarkably, the amorphous LaCoO3 synthesized at 450 °C (referred to as LCO-4) exhibits excellent OER catalytic activity. At an overpotential of 310 mV, it achieved a current density of 10 mA/cm-2 , exceedingly fast to 1 A/cm-2 at an overpotential of only 460 mV. Moreover, LCO-4 exhibited several advantageous features compared to pristine LaCoO3 and LaCoO3 amorphized at other two temperatures (350 °C, LCO-3, and 550 °C, LCO-5). The amorphized LCO-4 catalyst showed a higher electrochemically active surface area, a key factor in boosting catalytic performance. Additionally, LCO-4 demonstrated the lowest Tafel slope of 70 mVdec-1 , further highlighting its exceptional OER activity. Furthermore, the long-term stability of LCO-4 is notably superior than pristine LaCoO3 (LCO-P) and the other amorphized samples (LCO-3 and LCO-5). The enhanced catalytic activity of LCO-4 can be attributed to its unique disordered structure, small crystallite size, and higher concentration of oxygen vacancies in the final catalyst.

5.
RSC Adv ; 13(34): 23547-23557, 2023 Aug 04.
Article in English | MEDLINE | ID: mdl-37555091

ABSTRACT

Developing an efficient and non-precious bifunctional catalyst capable of performing water splitting and organic effluent degradation in wastewater is a great challenge. This article reports an efficient bifunctional nanocatalyst based on NiCo2O4, synthesized using a simple one-pot co-precipitation method. We optimized the synthesis conditions by varying the synthesis pH and sodium dodecyl sulfate (SDS) concentrations. The prepared catalyst exhibited excellent catalytic activity for the electrochemical oxygen evolution reaction (OER) and simultaneous methylene blue (MB) dye degradation. Among the catalysts, the catalyst synthesized using 1 g SDS as a surfactant at 100 °C provided the highest current density (658 mA cm-2), lower onset potential (1.34 V vs. RHE), lower overpotential (170 mV @ 10 mA cm-2), and smallest Tafel slope (90 mV dec-1) value. Furthermore, the OH˙ radicals produced during the OER electrochemically degraded the MB to 90% within 2 hours. The stability test conducted at 20 mA cm-2 showed almost negligible loss of the electrochemical response for OER, with 99% retention of the original response. These results strongly suggest that this catalyst is a promising candidate for addressing the challenges of wastewater treatment and energy generation.

6.
Environ Res ; 234: 116550, 2023 10 01.
Article in English | MEDLINE | ID: mdl-37437862

ABSTRACT

A facile two-step hydrothermal method was successfully used to prepare a photocatalyst Bi2WO6/WS2 heterojunction for methyl blue (MB) photodegradation. Fabricated photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), energy-dispersive X-ray analysis (EDX), and X-ray photoelectron spectroscopy (XPS). Band gap measurements were carried out by diffuse reflectance spectroscopy (DRS). Results indicated that the prepared heterostructure photocatalyst has increased visible light absorption. Photocatalytic performance was evaluated under sunlight irradiation for methylene blue (MB) degradation as a model dye. Variations in pH (4-10), amount of catalyst (0.025-0.1 g/L), and initial MB concentrations (5-20 ppm) were carried out, whereas all prepared catalysts were used to conduct the tests with a visible spectrophotometer. Degradation activity improved with the pH increase; the optimum pH was approximately 8. Catalyst concentration is directly related to degradation efficiency and reached 93.56% with 0.075 g of the catalyst. Among tested catalysts, 0.01 Bi2WO6/WS2 has exhibited the highest activity and a degradation efficiency of 99.0% in 40 min (min) for MB. MB photodegradation follows pseudo-first-order kinetics, and obtained values of kapp were 0.0482 min-1, 0.0337 min-1, 0.0205 min-1, and 0.0087 min-1 for initial concentrations of 5 ppm, 10 ppm, 15 ppm, and 20 ppm, respectively. The catalyst was reused for six cycles with a negligible decrease in the degradation activity. Heterostructure 0.01 Bi2WO6/WS2 has exhibited a photocurrent density of 16 µA cm-2, significantly higher than 2.0 and 4.5 µA cm-2 for the pristine WS2 and Bi2WO6, respectively. The findings from these investigations may serve as a crucial stepping stone towards the remediation of polluted water facilitated by implementing such highly efficient photocatalysts.


Subject(s)
Methylene Blue , Sunlight , Methylene Blue/chemistry , Photolysis , Light , Catalysis
7.
Membranes (Basel) ; 13(7)2023 Jul 19.
Article in English | MEDLINE | ID: mdl-37505044

ABSTRACT

Porous low-pressure membranes have been used as active membranes in water treatment and as support for thin-film composite membranes used in water desalination and gas separation applications. In this article, microfiltration polysulfone (PSf)mixed-matrix membranes (MMM) containing amine-functionalized graphene oxide (GO-NH2) were fabricated via a phase inversion process and characterized using XPS, SEM, AFM, DMA, XRD, and contact angle measurements. The effect of GO-NH2 concentration on membrane morphology, hydrophilicity, mechanical properties, and oil-water separation performance was analyzed. Significant enhancements in membrane hydrophilicity, porosity, mechanical properties, permeability, and selectivity were achieved at very low GO-NH2 concentrations (0.05-0.2 wt.%). In particular, the water permeability of the membrane containing 0.2 wt.% GO-NH2 was 92% higher than the pure PSf membrane, and the oil rejection reached 95.6% compared to 91.7% for the pure PSf membrane. The membrane stiffness was also increased by 98% compared to the pure PSf membrane. Importantly, the antifouling characteristics of the PSf-GO-NH2 MMMs were significantly improved. When filtering 100 ppm bovine serum albumin (BSA) solution, the PSf-GO-NH2 MMMs demonstrated a slower flux decline and an impressive flux recovery after washing. Notably, the control membrane showed a flux recovery of only 69%, while the membrane with 0.2 wt.% GO-NH2 demonstrated an exceptional flux recovery of 88%. Furthermore, the membranes exhibited enhanced humidity removal performance, with a permeance increase from 13,710 to 16,408. These results indicate that the PSf-GO-NH2 MMM is an excellent candidate for reliable oil-water separation and humidity control applications, with notable improvements in antifouling performance.

8.
Biosensors (Basel) ; 12(8)2022 Aug 11.
Article in English | MEDLINE | ID: mdl-36005025

ABSTRACT

Over the past several years, wearable electrophysiological sensors with stretchability have received significant research attention because of their capability to continuously monitor electrophysiological signals from the human body with minimal body motion artifacts, long-term tracking, and comfort for real-time health monitoring. Among the four different sensors, i.e., piezoresistive, piezoelectric, iontronic, and capacitive, capacitive sensors are the most advantageous owing to their reusability, high durability, device sterilization ability, and minimum leakage currents between the electrode and the body to reduce the health risk arising from any short circuit. This review focuses on the development of wearable, flexible capacitive sensors for monitoring electrophysiological conditions, including the electrode materials and configuration, the sensing mechanisms, and the fabrication strategies. In addition, several design strategies of flexible/stretchable electrodes, body-to-electrode signal transduction, and measurements have been critically evaluated. We have also highlighted the gaps and opportunities needed for enhancing the suitability and practical applicability of wearable capacitive sensors. Finally, the potential applications, research challenges, and future research directions on stretchable and wearable capacitive sensors are outlined in this review.


Subject(s)
Wearable Electronic Devices , Electrodes , Humans , Monitoring, Physiologic , Motion
9.
Small ; 18(26): e2107571, 2022 07.
Article in English | MEDLINE | ID: mdl-35620959

ABSTRACT

The integration of nanoarchitectonics and hydrogel into conventional biosensing platforms offers the opportunities to design physically and chemically controlled and optimized soft structures with superior biocompatibility, better immobilization of biomolecules, and specific and sensitive biosensor design. The physical and chemical properties of 3D hydrogel structures can be modified by integrating with nanostructures. Such modifications can enhance their responsiveness to mechanical, optical, thermal, magnetic, and electric stimuli, which in turn can enhance the practicality of biosensors in clinical settings. This review describes the synthesis and kinetics of gel networks and exploitation of nanostructure-integrated hydrogels in biosensing. With an emphasis on different integration strategies of hydrogel with nanostructures, this review highlights the importance of hydrogel nanostructures as one of the most favorable candidates for developing ultrasensitive biosensors. Moreover, hydrogel nanoarchitectonics are also portrayed as a promising candidate for fabricating next-generation robust biosensors.


Subject(s)
Biosensing Techniques , Nanostructures , Hydrogels/chemistry , Nanostructures/chemistry
10.
Nanomaterials (Basel) ; 11(12)2021 Dec 03.
Article in English | MEDLINE | ID: mdl-34947630

ABSTRACT

Due to the shortage of freshwater availability, reclaimed water has become an important source of irrigation water. Nevertheless, emergent contaminants such as antibiotics in reclaimed water can cause potential health risks because antibiotics are nonbiodegradable. In this paper, we report the adsorptive removal of azithromycin (AZM) antibiotics using activated porous carbon prepared from Azolla filiculoides (AF) (AFAC). The influence of the adsorption process variables, such as temperature, pH, time, and adsorbent dosage, is investigated and described. The prepared AFAC is very effective in removing AZM with 87% and 98% removal after the treatment of 75 min, at 303 and 333 K, respectively. The Langmuir, Temkin, Freundlich, and Dubinin-Radushkevich isotherm models were used to analyze the adsorption results. The Freundlich isotherm was best to describe the adsorption isotherm. The adsorption process follows second-order pseudo kinetics. The adsorption was endothermic (ΔH°= 32.25 kJ/mol) and spontaneous (ΔS° = 0.128 kJ/mol·K). Increasing the temperature from 273 to 333 K makes the process more spontaneous (ΔG° = -2.38 and -8.72 KJ/mol). The lower mean square energy of 0.07 to 0.845 kJ/mol confirms the process' physical nature. The results indicate that AFAC can be a potential low-cost adsorbent of AZM from aqueous solutions.

11.
Polymers (Basel) ; 13(8)2021 Apr 18.
Article in English | MEDLINE | ID: mdl-33919649

ABSTRACT

Polyimide-silica (PI-Silica) composites are of tremendous research interest as high-performance materials because of their excellent thermal and mechanical properties and chemical resistance to organic solvents. Particularly, the sol-gel method of fabricating such composites is popular for manipulating their properties. In this work, PI-silica composite films are synthesized by the sol-gel method and thermal imidization from the solution mixtures of hydrolyzed tetraethoxysilane (TEOS) (or glycidoxypropyltrimethoxysilane (GPMS)) modified silica and an aromatic polyamic acid (PAA) based on 3,3',4,4'-biphenyl tetracarboxylic dianhydride (BPDA)-p-phenylenediamine (PDA). The phase morphology of composites is found to be controlled by the substitution of TEOS with GPMS. Solid-state NMR spectroscopy is used to confirm the structural components of silica and GPMS-modified silica, whereas FT-IR results confirm the complete imidization of polyimide and composite film and suggest successful incorporation of Si-O-Si bonds into polyimide. The thermal, optical transmittance, and dielectric constant characterizations of pure polyimide and composite films are also carried out. Thermal stability of pure polyimide is found to be increased significantly by the addition of silica, whereas the partial substitution of TEOS with GPMS decreases the thermal stability of the composite, due to the presence of the alkyl organic segment of GPMS. The optical transmittance and dielectric constant of the composite films are controlled by manipulating the GPMS content.

12.
Nanomaterials (Basel) ; 11(3)2021 Feb 26.
Article in English | MEDLINE | ID: mdl-33652693

ABSTRACT

Silver nanoparticles (Ag NPs) and their nanocomposites with polymers are potent agents for antibacterial and disinfectant applications. The structural parameters of Ag-NPs, such as size, shape, and surface area, are very critical for developing appropriate formulations for the targeted applications. The impact of these factors on the performance of Ag NPs is analyzed. Ag NPs with a broad spectrum of antibacterial activities have already found applications in wound and burn dressing, food preservation, agricultural ponds, treatment for infected areas, coatings, water treatment, and other biomedical applications. Ag NPs are quite useful against antibiotic-resistant bacteria, but their level of toxicity needs careful investigation as their toxicity could be very harmful to human health and the environment. This review discusses the challenges and prospects of various Ag NPs and their composites. The review will enrich the knowledge about the efficiency and mechanism of various Ag nanoparticle-based antibacterial agents.

13.
J Hazard Mater ; 408: 124843, 2021 04 15.
Article in English | MEDLINE | ID: mdl-33421849

ABSTRACT

We report the nanoconfinement-mediated graphitic nanoporous carbon nitride (gNPCN) adsorbents with a high content of inbuilt basic nitrogen (N) (48%) by X-ray photoelectron spectroscopy (XPS) for efficient CO2 adsorption. The gNPCNs (gNPCN-150 and gNPCN-130) are synthesized using the mesoporous SBA-15 silica template and a single carbon-nitrogen (C-N) precursor (guanidine hydrochloride). The various adsorbents were utilized for investigating the influence of pore size (PS), surface area (SA), and type of adsorbent for CO2 adsorption performance. The capacity for CO2 capturing of gNPCN-150 reached 23.1 mmol/g at 0 °C under 30 bar pressure. This CO2 capturing capacity value was higher than the capacity gNPCN-130, SBA15, activated carbon (AC), and multiwalled carbon nanotube (MWCN) under identical conditions. The gNPCN materials exhibited superior CO2 adsorption ability that is ascribed to the presence of the highly organized mesoporosity, inbuilt high content of basic N site for adsorbing more CO2 through acid-base interaction, and tunable surface-structural properties. Moreover, the synthesis strategy is remarkably flexible in selecting C-N sources. This study features graphitic high-ordered nanoporous CN materials as a resourceful platform towards the efficient CO2 capture.

14.
J Hazard Mater ; 408: 124919, 2021 04 15.
Article in English | MEDLINE | ID: mdl-33388627

ABSTRACT

Graphitic carbon nitride with suitably incorporated functionality has attracted much interest in the areas of environmental treatments, clean energy, sensing, and photocatalyst. However, the role of graphitic nanoporous carbon nitride (NCN) matrix from single carbon-nitrogen (C-N) source, aminoguanidine HCl as a precursor and close intimate contact between silver nanoparticles (Ag NPs) dispersed in NCN and bacteria has rarely been demonstrated. Herein, we demonstrate a nanostructure of Ag NPs-incorporated NCN sample (NCN@Ag) as an antibacterial agent against both wild type and the multidrug-resistant Escherichia coli (E. coli) pathogens. In-situ ultrasonication method was used to ensure the homogeneous mixing of the Ag NPs and a single C-N precursor at the molecular level so that pore size (PS) (9.17 nm) of SBA15 silica could be impregnated with ultrasonicated Ag NPs and a single C-N precursor. The porous structure, compositions, and structural information of the final nanocomposites were confirmed by using various analytical techniques such as XRD, TEM, BET surface area (SA) measurements, XPS, and UV. Then, the antibacterial activities of the NCN and NCN@Ag against both wild type and the multidrug-resistant Escherichia coli (E. coli) pathogens were also carried out and results from the in-vitro studies have shown the excellent bactericidal effect of the highly dispersed Ag NPs containing NCN@Ag sample against both E. coli strains. Results have confirmed that the antibacterial activity of the NCN@Ag sample is found to be higher than pure NCN, indicating that in-situ incorporated Ag NPs in NCN matrix have played significant role for enhancing antibacterial activities. Surprisingly, in the presence of NCN@Ag, the reduction in minimum inhibitory concentration (MIC) was higher (64-fold reduction) compared to its susceptible wild type (32-fold reduction) E. coli. These results indicate the potential application of NCN@Ag for inactivating infectious bacterial pathogens implicated in multidrug resistance.


Subject(s)
Metal Nanoparticles , Nanopores , Anti-Bacterial Agents/pharmacology , Escherichia coli , Microbial Sensitivity Tests , Nitriles , Silver
15.
Curr Pharm Biotechnol ; 22(13): 1686-1704, 2021.
Article in English | MEDLINE | ID: mdl-33081684

ABSTRACT

Membrane separation is at the forefront of the technologies for desalination and wastewater treatment. However, current membranes have inherent limitations, including permeability/ selectivity trade-off and fouling susceptibility. To overcome these limitations, a new generation of advanced membranes based on nanomaterials has emerged. Among the nanomaterials, Graphene Oxide (GO) is regarded as the most promising nanomaterials due to its favorable characteristics such as hydrophilicity, tunable surface chemistry, large surface area, mechanical stability, bacteriostasis, and biocidal activities. There are currently three types of graphene-based membranes, i.e., nanoporous graphene/ GO, laminated GO, and mixed matrix membranes. The fabrication, applications, and limitations of the three classes of membranes are analyzed. After a brief introduction to membranes, graphene, GO, and GO functionalization, the recent advances in the fabrication of these membranes are presented. Relevant applications of these membranes in water treatment are discussed in light of the structureperformance relationship. Finally, the overall conclusion and our perspective on future research directions are provided.


Subject(s)
Graphite , Nanostructures , Water Purification , Membranes, Artificial
16.
Data Brief ; 32: 106197, 2020 Oct.
Article in English | MEDLINE | ID: mdl-32904345

ABSTRACT

Structure and microstructure characterization are very important for determining the membrane hydrophilicity, morphology, porosity, and mechanical properties that affect the membrane separation performance and durability. This article analyzes the morphological differences between graphene oxide (GO) and functionalized graphene oxide (f-GO) based on data from SEM imaging. nalysis of the morphology of mixed matrix membrane (MMMs) through SEM, mechanical properties through DMA and hydrophilicity through contact angle data. This dataset will support the original research article "Mixed matrix membranes containing aspartic acid functionalized graphene oxide for enhanced oil-water emulsion separation" (Abdalla, Wahab and Abdala, 2020; doi.org/10.1016/j.jece.2020.104269). The data reported here also include raw data for stress vs strain measurements, mass recorded during permeation test and pure water fluxes at different pressures for all prepared MMMs.

17.
Sci Rep ; 9(1): 16050, 2019 11 05.
Article in English | MEDLINE | ID: mdl-31690767

ABSTRACT

The anadromous Hilsa shad (Tenualosa ilisha) live in the Bay of Bengal and migrate to the estuaries and freshwater rivers for spawning and nursing of the juveniles. This has led to two pertinent questions: (i) do all Hilsa shad that migrate from marine to freshwater rivers come from the same population? and (ii) is there any relationship between adults and juveniles of a particular habitat? To address these questions, NextRAD sequencing was applied to genotype 31,276 single nucleotide polymorphism (SNP) loci for 180 individuals collected from six strategic locations of riverine, estuarine and marine habitats. FST OutFLANK approach identified 14,815 SNP loci as putatively neutral and 79 SNP loci as putatively adaptive. We observed that divergent local adaptations in differing environmental habitats have divided Hilsa shad into three genetically structured ecotypes: turbid freshwater (Western Riverine), clear freshwater (Eastern Riverine) and brackish-saline (Southern Estuarine-Marine). Our results also revealed that genes involved in neuronal activity may have facilitated the juveniles' Hilsa shad in returning to their respective natal rivers for spawning. This study emphasized the application of fundamental population genomics information in strategizing conservation and management of anadromous fish such as Hilsa shad that intersect diverse ecotypes during their life-history stages.


Subject(s)
Animal Migration , Ecotype , Fishes/physiology , Genotype , Polymorphism, Single Nucleotide , Animals , Estuaries , Rivers
18.
RSC Adv ; 9(30): 17194-17202, 2019 May 29.
Article in English | MEDLINE | ID: mdl-35519874

ABSTRACT

NiMoS2 nanoparticles supported on carbon, synthesized by a microemulsion method were used as a nanocatalyst for hydrodeoxygenation (HDO) of a lignin model compound - guaiacol. Two types of carbon supports - mesoporous carbon (CMK-3) and activated carbon (AC) with a predominantly microporous structure, were studied to investigate the role of porosity and nature of the porous structure in catalyst activity. The activity of NiMoS2/AC resulted in the complete guaiacol conversion at 13 h of reaction time to produce phenol (31.5 mol%) and cyclohexane (35.7 mol%) as the two main products. Contrastingly, NiMoS2/CMK-3 needed a much lesser reaction time (6 h) to attain a similar conversion of guaiacol but gave different selectivities of phenol (25 mol%) and cyclohexane (55.5 mol%). Increased cyclohexane production with NiMoS2/CMK-3 implied better deoxygenation of MoS2 and enhanced hydrogenation capacity of Ni since phenol is a partially deoxygenated product of guaiacol while cyclohexane is a completely deoxygenated and hydrogenated product. The superior catalytic activity and deoxygenating behavior of NiMoS2/CMK-3 catalysts could be attributed to the organized mesoporosity of the CMK-3 support in relation to the improved active phase distribution and access to active sites that facilitate the conversion of the reaction's product. Recyclability study implied NiMoS2/CMK-3 was more stable without significant changes in the catalytic activity even after three reaction cycles.

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