Sodium Borohydride Concentration Research Articles

GREEN SYNTHESIS OF CaO–PdNps FROM LAWSONIA INERMIS LEAF EXTRACT: CATALYTIC REDUCTION OF METHYLENE BLUE WITH CENTRAL COMPOSITE DESIGN-ENHANCED NEURAL NETWORK PREDICTION

In this work, small-sized CaO–PdNps nanocomposites were synthesized using Lawsonia inermis leaf extract as a reducing and capping agent. X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR) were used to analyze the produced nanocomposites. Based on these investigations, the average particle size was found to be [Formula: see text][Formula: see text]nm, with a predominantly spherical morphology. The resulting nanocomposite was then tested for catalytic activity in methylene blue reduction. The mass of the catalyst and dye, the concentration of sodium borohydride ([NaBH4]), and the reaction time were all optimized using a central composite design (CCD). A significant correlation between predicted and experimental degradation percentages was shown by the CCD model ([Formula: see text]), which also proved statistically significant (p-[Formula: see text]). Furthermore, a deep learning neural network (DLNN) was used to improve the prediction accuracy over and beyond CCD. There was a good connection between the two models as a result of using the CCD output as DLNN validation data. Mean absolute error (MAE), mean squared error (MSE), root mean squared error (RMSE), mean absolute percentage error (MAPE), and [Formula: see text] were used to assess the performance of the DLNN. The results ([Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text]) validated that all four metrics were successful in forecasting the percentage of degradation.

Multiplicative rGO/Cu-BDC MOF for 4-nitrophenol reduction and supercapacitor applications

Two-dimensional nanosheets, with their distinct characteristics, are widely used in various applications such as water splitting, supercapacitors, catalysis etc. In this research, we produced Cu-BDC MOF nanosheets by using Cu2O nanotubes for metal ions and H2BDC as the organic linker. We combined these Cu-BDC MOF nanosheets with reduced graphene oxide (rGO) to form a nanocomposite. The collaboration between Cu-BDC MOF and rGO boosts both the catalytic reduction of 4-nitrophenol and the electrochemical capabilities. The conversion of 4-nitrophenol to 4-aminophenol is achieved using sodium borohydride as both a reducing agent and a catalyst. The study explores the impact of different concentrations of 4-nitrophenol and sodium borohydride on catalytic efficiency. The increase in sodium borohydride concentration enhances catalytic efficiency by providing more BH4− ions and electrons for the reduction process. The catalytic reduction process adheres to the Langmuir–Hinshelwood mechanism with apparent pseudo-first-order kinetics. Specifically, Cu-BDC MOF and rGO/Cu-BDC MOF exhibit specific capacities of 468.4 mA h/g and 656.4 mA h/g at a current density of 2 A/g, respectively, while also enhancing the operating voltage window. Therefore, electrodes based on rGO/Cu-BDC MOF nanosheets present a novel approach for environmental remediation and energy storage applications across various fields.

Application of Palladium Mesoporous Carbon Composite Obtained from a Sustainable Source for Catalyzing Hydrogen Generation Reaction

Alternative fuel sources are necessary in today’s economic and environmental climate. Hydrogen fuel arises as an environmentally friendly and energy dense option; however, the volatility of hydrogen gas makes it dangerous to store and utilize. The evolution of hydrogen from hydrogen feedstock materials may prove to overcome this safety barrier, but a catalyst for this reaction is necessary to optimize production. In this work, a composite catalyst comprised of palladium nanoparticles embedded on mesoporous carbon materials (Pd-MCM) was synthesized and characterized by Transmission Electron Microscope (TEM), Powder X-Ray diffraction (P-XRD), Scanning Electron Microscope (SEM) and Energy Dispersive Spectroscope (EDS). Various reaction conditions such as concentration of reactant, temperature, and pH were applied in measuring the catalytic activity of Pd-MCM. Results show the catalytic activity of the Pd-MCM composite catalysts increased with increasing concentrations of sodium borohydride, increasing temperature, and lower pH. The reaction involving the Pd-MCM composite had an activation energy of 27.9 kJ mol−1. Reusability trials showed the Pd-MCM composite remained stable for up to five consecutive trials.

Ni-B-PTFE Nanocomposite Co-Deposition on the Surface of 2A12 Aluminum Alloy.

The spinning cup, a crucial component of textile equipment, relies heavily on 2A12 aluminum alloy as its primary raw material. Commonly, electroplating and chemical nickel-phosphorus (Ni-P) plating are employed to improve the surface characteristics of the object. Nevertheless, due to the growing expectations for the performance of aluminum alloys, the hardness and wear resistance of Ni-P coatings are no longer sufficient to fulfill industry standards. This study primarily focuses on the synthesis of Ni-B-PTFE nanocomposite chemical plating and its effectiveness when applied to the surface of 2A12 aluminum alloy. We examine the impact of the composition of the plating solution, process parameters, and various other factors on the pace at which the coating is deposited, the hardness of the surface, and other indicators of the coating. The research findings indicate that the composite co-deposited coating achieves its optimal surface morphology when the following conditions are met: a nickel chloride concentration of 30 g/L, an ethylenediamine concentration of 70 mL, a sodium borohydride concentration of 0.6 g/L, a sodium hydroxide concentration of 90 g/L, a lead nitrate concentration of 30 mL, a pH value of 12, a temperature of 90 °C, and a PTFE concentration of 10 mL/L. The coating exhibits consistency, density, a smooth surface, and an absence of noticeable pores or fissures. The composite co-deposited coating exhibits a surface hardness of 1109 HV0.1, which significantly surpasses the substrate's hardness of 232.38 HV0.1. The Ni-B-PTFE composite coating exhibits an average friction coefficient of around 0.12. It has a scratch width of 855.18 μm and a wear mass of 0.05 mg. This coating demonstrates superior wear resistance when compared to Ni-B coatings. The Ni-B-PTFE composite coating specimen exhibits a self-corrosion potential of -6.195 V and a corrosion current density of 7.81 × 10-7 A/cm2, which is the lowest recorded. This enhances its corrosion resistance compared to Ni-B coatings.

Fabrication of CuO derived reduced graphene oxide photocatalyst for the strategic decolorization of Congo red from an aqueous environment

Herein, we designed a novel reduced graphene oxide functionalized copper oxide (rGO-CuO) nanocomposite material through simple method. The synthesized rGO-CuO nanocomposite is rigorously characterized via advanced techniques including X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). These characterizations reveal crucial insights into the nanocomposite crystalline attributes, phase purity, morphological characteristics, and elemental composition, collectively confirming its successful fabrication. Furthermore, the synthesized nanocomposite is subsequently used for the proficient decolorization of Congo Red (CR) dye within an aqueous medium employing a careful optimization of experimental variables including the concentration of sodium borohydride (NaBH4), solar irradiation, and catalytic dosage. The developed photocatalytic achieved 98.7 % degradation of CR dye at a minimal catalyst dosage of 2.4 mg in a 5-min reaction time. Notably, the nanocomposite exhibits reusability for up to five cycles with 88 % efficiency, underscoring the durability and reliability of the rGO-CuO photocatalyst. Moreover, the kinetic study evaluation demonstrated that the decolorization of dye at surface of the catalyst follows pseudo first order reaction. The rGO-CuO nanocomposite could be a suitable candidate for the rapid photocatalytic degradation of CR dye not only at low level but also at industrial scale.

Synthesis and characterization of cobalt doped zinc oxide nanoparticles and their application for catalytic reduction of methylene blue dye

The co-precipitation approach has been used in the current research work to synthesize cobalt-doped zinc oxide nanoparticles (ZnO NPs) employing zinc and cobalt nitrate hexahydrate as precursor salts. Ultraviolet-visible spectra and Fourier transform infrared were used to confirm that the manufacturing procedure was efficient and that the synthesized sample contained a range of unique binding sites. The catalytic efficacy of the prepared nanoparticles for the reduction of Methylene blue dye in the presence of NaBH4 as a reducing agent has been investigated. The concentration of methylene blue, the catalyst dose, and the concentration of sodium borohydride all play significant roles in the catalytic reduction of methylene blue (MB). The best result for the complete reduction of methylene blue was obtained in 14 min of reaction time. Catalytic reduction of methylene blue in the involvement of synthesized nanoparticles was found to be followed by the Langmuir-Hinshelwood mechanism. Concerning this process, the reduction reaction is affected by the quantity of methylene blue, catalyst, and sodium borohydride. This effective catalytic activity of Co-doped ZnO nanoparticles suggests that these NPs can work wonders as nano-catalysts for the reduction of hazardous dyes.

Cobalt nanoparticle synthesis through the mechanochemical and chemical reduction method as a highly active and reusable catalyst for H2 production via sodium borohydride hydrolysis process

The process of hydrolysis of sodium borohydride is a new and clean method for the production of hydrogen. In this study, cobalt nanoparticles were synthesized by the mechanochemical and chemical reduction methods, and their catalytic performance was compared. The effect of using different cobalt precursors and reducing agents was investigated for the sample prepared via the chemical reduction method. The results showed that the cobalt catalysts synthesized through the chemical reduction method possessed better catalytic performance. Also, the sample prepared using cobalt nitrate and sodium borohydride had a higher hydrogen generation rate (HGR), which was equal to 3272.7 ml min−1g−1. The kinetics of the cobalt catalyst in the process have also been investigated, revealing that the rate of hydrogen production is dependent on the concentrations of sodium borohydride and sodium hydroxide, the catalyst dosage, and the process temperature. The crystal size of this catalyst was 21.6 nm with spherical agglomerated particles. The BET area of the best sample and its activation energy was equal to 11.18 m2g-1 and 22.3 kJmol-1, respectively. This catalyst was also stable in successive cycles.

Synthesis of Trimetallic Nanoparticle (NiCoPd)-Supported Carbon Nanofibers as a Catalyst for NaBH4 Hydrolysis.

The generation of H2 via the catalytic hydrolysis of sodium borohydride (SBH) has promise as a practical and secure approach to produce H2, a secure and environmentally friendly energy source for the foreseeable future. In this study, distinctive trimetallic NiCoPd nanoparticle-supported carbon nanofibers (NiCoPd tri-NPs@CNFs) is synthesized via sol-gel and electrospinning approaches. The fabricated trimetallic catalysts show an excellent catalytic performance for the generation of H2 from the hydrolysis of SBH. Standard physicochemical techniques were used to characterize the as-prepared NiCoPd tri-NPs@CNFs. The results show that NiCoPd tri-NPs@CNFs is formed, with an average particle size of about 21 nm. When compared to NiCo bimetallic NP @CNFS, all NiCoPd tri-NPs@CNFs formulations demonstrated greater catalytic activates for the hydrolysis of SBH. The improved catalytic activity may be due in the majority to the synergistic interaction between the three metals in the trimetallic architecture. Furthermore, the activation energy for the catalytic hydrolysis of SBH by the NiCoPd tri-NPs@CNFs was determined to be 16.30 kJ mol-1. The kinetics studies show that the reaction is of a first order with respect to the catalyst loading amount and a half order with respect to the SBH concentration [SBH].

Synthesis of Copper/Sulfur Co-Doped TiO2-Carbon Nanofibers as Catalysts for H2 Production via NaBH4 Hydrolysis

Copper/sulfur co-doped titanium dioxide-carbon nanofibers (Cu,S-codoped TiO2 NPs, decorated-CNFs) catalysts were synthesized using the electrospinning process to produce composite nanofibers (NFs). These composite NFs were utilized for the hydrolysis of sodium borohydride (SBH) to generate hydrogen gas (H2), taking advantage of their catalytic properties. The experimental results demonstrated that using 100 mg of composite NFs yielded the highest catalytic activity for H2 production, generating 79 mL of H2 gas within 6 min at 25 °C and 1000 revolutions per minute (rpm) using 1 mmol of SBH. As the catalyst dosage was reduced from 100 mg to 75, 50, and 25 mg, the reaction time increased by 9, 13, and 18 min, respectively. Kinetic studies revealed that the reaction rate followed a first-order reaction, indicating a direct proportionality between the rate of reaction and the catalyst amount. Additionally, it was observed that the concentration of SBH had no influence on the reaction rate, suggesting a zero-order reaction. Increasing the reaction temperature resulted in a reduced reaction time. The activation energy was determined to be 26.16 kJ mol−1. The composite NFs maintained their superior performance over five iterations. These findings suggest that composite nanofibers have the potential to serve as a cost-effective alternative to expensive catalysts in hydrogen production.

Mercury Determination in Fish Using Cold Vapour-Atomic Absorption Spectrometry (CV-AAS) with Sodium Borohydride (NaBH4) as the Reductor

Marine fish can potentially accumulate heavy metal pollutants, such as mercury, from anthropogenic activities that can harm people who consume it. Marine fishes like Bandeng fish (Chanos chanos), Banjar fish (Rastrelliger kanagurta), Bawal Hitam fish (Parastromateus niger), Selar Kuning fish (Atule mate), Tenggiri fish (Scomberomorini), and Tuna fish (Thunnini) are consumed a lot by people in Bandung City. All these fish were analyzed using the CV-AAS method with the United States – Environment Protection Agency (USEPA, 2006), and the reducing agent was replaced by stannous (II) chloride with sodium borohydride. Variations in the sample preparation process include drying the sample using an oven and freeze dryer. SEM-EDX in the frozen-dried samples shows that the fibbers’ morphology is intact, while the fibbers are damaged in the hot-dried samples. During characterization using FTIR, there is a slight shift in wave number. The mercury concentrations obtained from every sample were below 0.5 mg/kg based on the Indonesian National Standard (SNI) 2009 standard for total mercury in fish. Therefore, it can be concluded that the samples are safe to be consumed. Validation methods showed that 0.3% sodium borohydride as the reductor can be used to analyze mercury and replace stannous (II)chloride. However, further studies are needed to determine the optimal concentration of sodium borohydride (NaBH4) in the marine fish samples as a reduction agent.

Biohydrogen production via green silver nanoparticles synthesized through biomass of Ulva lactuca bloom

Ulva lactuca is a marine green seaweed. Its bloom based biomass accumulated in the İzmir bay and is collected by local authorities. In this investigation, an alternative solution was proposed to utilize the biomass of U. lactuca to produce biohydrogen via green synthesized silver nanoparticles. According to the results, the optimum conditions related to silver nanoparticle production such as pH, temperature, biomass concentration, silver nitrate concentrations, and incubation time were determined to be 11, 25 °C, 10 mg/mL, 4 mM, and 3 days, respectively. Effective conditions for biohydrogen production such as pH, temperature, agitation rate, and sodium borohydride concentration were found to be 7, 50 °C, 250 rpm and 150 mM, respectively. These parameters are also modelled with an artificial neural network. The data presented here provide recommendations for producing biohydrogen from waste algae and helping reduce carbon emissions for better environment and future.

Boosted visible-light-driven degradation over stable ternary heterojunction as a plasmonic photocatalyst: Mechanism exploration, pathway and toxicity evaluation

The incorporation of plasmonic metals into semiconductors forming heterojunction photocatalysts is a promising route to enhance the photocatalytic performance in visible light. In this work, we reported the visible-light-driven one-dimensional (1D) nanostick silver/silver sulfide (Ag/Ag2S) photocatalyst combining with two-dimensional (2D) nanosheet reduced graphene oxide intersected by hollow structure (h-RGO) was prepared via a feasible approach at room temperature. The density of Ag depositing on the surface of Ag2S was easily tuned by the concentration of sodium borohydride and the silicon dioxide nanospheres were employed as templates in the preparation of h-RGO by the layer-by-layer (LBL) assembly. The ternary plasmonic Ag/Ag2S/h-RGO photocatalysts exhibited better photocatalytic performance for degradation of naphthalene (95.95%) and 1-naphthol (98.65%) under visible light than the pure Ag2S, composite Ag/Ag2S and composite Ag/Ag2S/RGO. Localized surface plasmon resonance of Ag, heterojunction formed between Ag/Ag2S and RGO and the unique characteristics of h-RGO, which included higher specific surface areas, more efficient reflections of light and more active sites than RGO for boosting separation efficiency of charge carriers, were all responsible for such enhancement. By combining the characterization results with various computations, the mechanism, potential degradation pathways and the toxicity of the generated intermediates for photodegradation were examined. In addition to offering profound insight into the expansion of effective plasmonic photocatalysts with novel structures, the current study is beneficial to ease the environmental crisis to a certain extent.

Optimization of ultrasonic-assisted approach for synthesizing a highly stable biocompatible bismuth-coated iron oxide nanoparticles using a face-centered central composite design

The incorporation of additional functional groups such as bismuth nanoparticles (Bi NPs) into magnetite nanoparticles (Fe3O4 NPs) is critical for their properties modification, stabilization, and multi-functionalization in biomedical applications. In this work, ultrasound has rapidly modified iron oxide (Fe3O4) NPs via incorporating their surface through coating with Bi NPs, creating unique Fe3O4@Bi composite NPs. The Fe3O4@Bi nanocomposites were synthesized and statistically optimized using an ultrasonic probe and response surface methodology (RSM). A face-centered central composite design (FCCD) investigated the effect of preparation settings on the stability, size, and size distribution of the nanocomposite. Based on the numerical desirability function, the optimized preparation parameters that influenced the responses were determined to be 40 ml, 5 ml, and 12 min for Bi concentration, sodium borohydride (SBH) concentration, and sonication time, respectively. It was found that the sonication time was the most influential factor in determining the responses. The predicted values for the zeta potential, hydrodynamic size, and polydispersity index (PDI) at the highest desirability solution (100%) were −45 mV, 122 nm, and 0.257, while their experimental values at the optimal preparation conditions were −47.1 mV, 125 nm, and 0.281, respectively. Dynamic light scattering (DLS) result shows that the ultrasound efficiently stabilized and functionalized Fe3O4NPs following modification to Fe3O4@Bi NPs, improved the zeta potential value from –33.5 to −47.1 mV, but increased the hydrodynamic size from 98 to 125 nm. Energy dispersive spectroscopy (EDX) validated the elemental compositions and Fourier transform infrared spectroscopy (FTIR) confirmed the presence of Sumac (Rhus coriaria) compounds in the composition of the nanocomposites. The stability and biocompatibility of Fe3O4@Bi NPs were improved by using the extract solution of the Sumacedible plant. Other physicochemical results revealed that Fe3O4NPs and Fe3O4@Bi NPs were crystalline, semi-spherical, and monodisperse with average particle sizes of 11.7 nm and 19.5 nm, while their saturation magnetization (Ms) values were found to be 132.33 emu/g and 92.192 emu/g, respectively. In vitro cytotoxicity of Fe3O4@Bi NPs on the HEK-293 cells was dose- and time-dependent. Based on our findings, the sonochemical approach efficiently produced (and RSM accurately optimized) an extremely stable, homogeneous, and biocompatible Fe3O4@Bi NPs with multifunctional potential for various biomedical applications.

Membrane Nanofiber-Supported Cobalt–Nickel Nanoparticles as an Effective and Durable Catalyst for H2 Evolution via Sodium Borohydride Hydrolysis

The successful support of bimetallic NiCo alloy nanoparticles (NPs) on poly(vinylidene fluoride-co-hexafluoropropylene) nanofibers (PVDF-HFP NFs) was achieved through electrospinning (ES) and in situ reduction. The synthesis and physicochemical characterization of Ni-Co@PVDF-HFP NFs with a range of bimetallic compositions (Ni1-xCox, x = 0, 0.1, 0.3, 0.5, 0.7, 0.9, and 1) supported on PVDF-HFP NFs was undertaken. In comparison to their counterparts (Ni-PVDF-HFB and Co-PVDF-HFB), the bimetallic hybrid NF membranes demonstrated a significantly increased volume of H2 generation from sodium borohydride (SBH). The high performance of bimetallic catalysts can be attributed mostly to the synergistic impact of Ni and Co. Among all fabricated catalysts, Ni0.3Co0.7@PVDF-HFP produced the highest H2 production in a short time. The maximum generated H2volume was 118 mL in 11.5, 9, 6, and 4.5 min at 298, 308, 318, and 328 K, respectively. Kinetic analyses showed that the hydrolysis process proceeded as a quasi-first-order reaction with respect to the amount of catalyst and as a zero-order reaction with respect to the concentration of SBH. Thermodynamics studies were also undertaken and the parameters were calculated as Ea, ΔS, and ΔH = 30.17 kJ/mol, 0.065 kJ/mol, and 27.57 kJ/mol K, respectively. The introduced NFs can be easily separated and reused, which facilitates their industrialization and commercialization applications in hydrogen storage systems.

Electrospun Co Nanoparticles@PVDF-HFP Nanofibers as Efficient Catalyst for Dehydrogenation of Sodium Borohydride.

Metallic Co NPs@poly(vinylidene fluoride-co- hexafluoropropylene) nanofibers (PVFH NFs) were successfully synthesized with the help of electrospinning and in situ reduction of Co2+ ions onto the surface of PVFH membrane. Synthesis of PVFH NFs containing 10, 20, 30, and 40 wt% of cobalt acetate tetrahydrate was achieved. Physiochemical techniques were used to confirm the formation of metallic Co@PVFH NFs. High catalytic activity of Co@PVFH NFs in the dehydrogenation sodium borohydride (SBH) was demonstrated. The formulation with 40 wt% Co proved to have the greatest performance in comparison to the others. Using 1 mmol of SBH and 100 mg of Co@PVFH NFs, 110 mL of H2 was produced in 19 min at a temperature of 25 °C, but only 56, 73, and 89 mL were produced using 10, 20, and 30 wt% Co, respectively. With the rise of catalyst concentration and reaction temperature, the amount of hydrogen generated increased. By raising the temperature from 25 to 55 °C, the activation energy was lowered to be 35.21 kJ mol-1 and the yield of H2 generation was raised to 100% in only 6 min. The kinetic study demonstrated that the reaction was pseudo-first order in terms of the amount of catalyst utilized and pseudo-zero order in terms of the SBH concentration. In addition, after six cycles of hydrolysis, the catalyst showed outstanding stability. The suggested catalyst has potential applications in H2 generation through hydrolysis of sodium borohydride due to its high catalytic activity and flexibility of recycling.

CuNi Alloy NPs Anchored on Electrospun PVDF-HFP NFs Catalyst for H2 Production from Sodium Borohydride.

Non-noble CuxNi1-x (x = 0, 0.1, 0,2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1) alloy nanoparticles supported on poly(vinylidene fluoride-co-hexafluoropropene) (PVDF-HFP) nanofibers (NFs) are successfully fabricated. The fabrication process is executed through an electrospinning technique and in situ reduction in Cu2+ and Ni2+ salts. The as-synthesized catalysts are characterized using standard physiochemical techniques. They demonstrate the formation of bimetallic NiCu alloy supported on PVDF-HFP. The introduced bimetals show better catalytic activity for sodium borohydride (SBH) hydrolysis to produce H2, as compared to monometallic counterparts. The Cu0.7 Ni0.3/PVDF-HFP catalyst possesses the best catalytic performance in SBH hydrolysis as compared to the others bimetallic formulations. The kinetics studies indicate that the reaction is zero order and first order with respect to SBH concentration and catalyst amount, respectively. Furthermore, low activation energy (Ea = 27.81 kJ/mol) for the hydrolysis process of SBH solution is obtained. The excellent catalytic activity is regarded as the synergistic effects between Ni and Cu resulting from geometric effects over electronic effects and uniform distribution of bimetallic NPs. Furthermore, the catalyst displays a satisfying stability for five cycles for SBH hydrolysis. The activity has retained 93% from the initial activity. The introduced catalyst has broad prospects for commercial applications because of easy fabrication and lability.

Parametric Study of Gold Nanoparticles Synthesis under Micro-Continuous Flow Conditions.

The synthesis of gold nanoparticles (GNPs) using chemical reduction in batch and microreactor methods has been reported. A parametric study of the effect of several parameters on the size of gold nanoparticles was performed in batch synthesis mode using the modified Martin method. The best-obtained conditions were used to synthesize gold nanoparticles using a glass chip microreactor, and the size of the resulting GNPs from both methods was compared. The presence of polyvinyl alcohol (SC) was used as a capping agent, and sodium borohydride (SB) was used as a reducing agent. Several parameters were studied, including HAuCl4, SC, SB concentrations, the volumetric ratio of SB to gold precursor, pH, temperature, and mixing speed. Various techniques were used to characterize the resulting nanoparticles, including Atomic Absorbance spectroscopy (AAS), Ultraviolet-visible spectroscopy (UV-Vis), and dynamic light scratching (DLS). Optimum conditions were obtained for the synthesis of gold nanoparticles. Under similar reaction conditions, the microreactor consistently produced smaller nanoparticles in the range of 10.42-11.31 nm with a reaction time of less than 1 min.

Electrospun nickel nanoparticles@poly(vinylidene fluoride-hexafluoropropylene) nanofibers as effective and reusable catalyst for H2 generation from sodium borohydride

Nickel nanoparticles (Ni NPs) supported on Poly(vinylidene fluoride- co -hexafluoropropylene) nanofibers (PVDF-HFP NFs) were successfully synthesized through electrospinning and in-situ reduction of Ni 2+ salts into the surface of PVDF-HFP NFs to form metallic Ni NPs@PVDF-HFP NFs. Different percentages of nickel acetate tetrahydrate (NiAc) (10 %, 20 %, 30 %, 40 % wt.) based PVDF-HFP. The formation of tiny metallic Ni NPs @PVDF-HFP membrane NFs was demonstrated using standard physiochemical techniques. Nanofibers membranes have demonstrated good catalytic activity in H 2 production from sodium borohydride (NaBH 4 ). The sample composed of 40 %wt Ni showed the highest catalytic activity compared to the other formulations. Whereas 103 mL of H 2 , from the hydrolysis of 1.34 mmol NaBH 4 , was produced using 40 wt% NiAc compared to 68 mL, 81 mL, and 93 mL for 10 wt%, 20 wt%, and 30 wt% NiAc, respectively, in 60 min at 25 °C. The hydrogen generation has been enhanced with an increase in the Nanofibers membrane amount and reaction temperature. The latter results in a low activation energy (23.52 kJ mol −1 ). The kinetics study revealed that the reaction was pseudo-first-order in sodium borohydride concentration and catalyst amount. Furthermore, the catalyst exhibits satisfactory stability in the hydrolysis process for ten cycles. Because of its easy recyclability, the introduced catalyst has a wide range of potential applications in the generation of H 2 from sodium borohydride hydrolysis.

Unraveling the facile reproducible modeled approach for bifunctional catalytic decorated polydopamine coated sponge composite for hydrogen generation

Continuous, flexible, and pure hydrogen (H2) gas supply to the portable, and compact shape proton exchange membrane fuel cells and other type of fuel cells is considered as one of the key factor to be solved for researchers. In this research study, we develop the facile strategy to synthesize the novel, multipurpose catalytic decorated polydopamine coated sponge (CDPCS) composite for continuous H2 generation for a long period of time as well as storage of solution within the composite. We explore the most efficient, light weight, hydrophilic commercial sponge, that is, wood pulp sponge (WPS), and binder, that is, polydopamine (PDA). Decoration of platinum nano particles and using of sodium borohydride solution are carried out as a case study by using as-synthesized CDPCS. Various characterization techniques such as scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Brunauer-Emmett-Teller (BET) analysis and energy dispersive X-ray (EDX) analysis are successfully employed to confirm the presence and size of nano particles and successfully coating of PDA layer. Hydrogen production performance of CDPCS with respect to different mass contents of Pt nanoparticles, molar concentration of sodium borohydride and at different temperature is investigated in this research study. An 87% yield of hydrogen generation has been achieved with 18 mg contents of Pt nano particles and 3 M concentration of sodium borohydride at room temperature. We believe that our conducted research study with respect to novel, facile, reproducible designed CDPCS based composites will be highly promising to simplify the hydrogen generation system for rapidly developed portable and wearable electronic devices.

Effect of heat-treatment temperature and borohydride concentration on corrosion behaviour of ENB coating

Electroless Ni-B (ENB) alloy coatings are extensively used due to their good tribological, physical, electrical and mechanical properties. The behaviour of coatings generally depends on the concentration of bath parameters, heat-treatment temperature, as well as heat-treatment duration. The current study was carried out to deposit coatings over steel specimens with various NaBH4 concentrations and heat-treated at various temperatures to study the significance of NaBH4 concentration as well as heat-treatment temperature on corrosion resistance of the Ni-B coatings. Ni-B coatings were heat-treated for an hour at different temperatures for example, 350°C, 450°C and 550°C. Electrochemical impedance spectroscopy (EIS) and Potentiodynamic polarization (PDP) test methods were employed to analyse the corrosion behaviour of the as-deposited as well as heat-treated coatings. The tests were conducted against a corrosive environment consisting of 3.5% NaCl solution. It was observed that the as-deposited coatings with low boron content exhibit a mixture of amorphous and nanocrystalline structures. The same gradually becomes amorphous with the rise in sodium borohydride concentration. The increase in boron content with sodium borohydride concentration in the coating bath led to the transformation of phase structure. This amorphous phase structure of as-deposited coatings further transforms into a crystalline structure upon heat treatment. This crystallinity increases with heat-treatment temperature. The as-deposited coatings show cauliflower-like surface morphology at all concentrations of NaBH4 but the same becomes a coarse-grained structure with clustered aggregates leading to a rough surface. The as-deposited coatings show better corrosion resistance behaviour compared to heat-treated ones, especially at the higher temperature.