Effect Of Precursor Concentration Research Articles

Rapid synthesis of cobalt manganese phosphate by microwave-assisted hydrothermal method and application as positrode material in supercapatteries

Electrochemical energy storage devices with high specific capacity are of utmost important for the next-generation electronic devices. Supercapatteries (SCs) are highly demanded energy storage devices nowadays as these bridge the low energy supercapacitors and low power batteries. Herein, we report a rapid synthesis of cobalt manganese phosphate (COMAP) by microwave-assisted hydrothermal method and facile fabrication of SCs using electrodes comprising of COMAP as positrode material. The effect of precursor concentration on the microstructure and surface morphology of the COMAP samples are examined initially. Further, the electrochemical performance of COMAP electrodes is studied systematically in 3 M KOH (aqueous) electrolyte. COMAP exhibits excellent charge storage capabilities where type of charge storage mechanism is found to be battery-type based on the calculation obtained from Dunn’s method. The SC electrode fabricated with COMAP synthesized using cobalt: manganese precursor ratio as 80:20 exhibits a highest specific capacity of 191.4 C/g at a scan rate of 1 mV/s. An asymmetric SC (ASC) cell fabricated with COMAP as positrode and activated carbon (AC) as negatrode exhibits a specific capacity of 165.5 C/g at a current density of 1.8 A/g. The COMAP//AC ASC cell exhibits an energy density of 34.1 Wh/kg at a corresponding power density of 1875 W/kg at a current density of 1.8 A/g.

Effect of precursor concentration on the growth of magnesium oxide nanomaterials by direct heating method

Various methods have been developed for the preparation of MgO nanomaterials. However, they often suffer from limitations such as high cost, lengthy synthesis times, and excessive power consumption. In response, a direct heating (DH) method has been developed to address these challenges, enabling rapid (< 10 min) and cost-effective production of MgO nanomaterials. In this study, the DH process was optimized by investigating the influence of precursor solution concentrations (0.01 M to 0.10 M) on the growth of MgO nanomaterials on wire surfaces. Analyses utilizing Fourier Transform Infrared Spectroscopy (FTIR), Energy Dispersive X-ray Spectroscopy (EDX), and X-ray Photoelectron Spectroscopy (XPS) confirmed the formation of MgO. Field Emission Scanning Electron Microscopy (FESEM) revealed that the nanomaterials predominantly nano-walls and particles. The optimized synthesis conditions for MgO nanomaterials requires the heating of 0.10 M Mg(NO3)2·6H2O precursor at 50 W.h. for 10 min. Under this specific condition, a favourable surface coverage of 81.54% was achieved where the MgO nanowalls produced has demonstrated promising capability to remove Methylene Blue (MB) dye under UV irradiation. In conclusion, DH technique is a favourable alternative route to synthesize MgO nanomaterial in a simple, cost-and -time efficient and environmentally friendly way.

Study on the Effects of Precursor Concentration and Annealing Process of In2O3 thin Films Prepared by Sol-gel Method

Study on the Effects of Precursor Concentration and Annealing Process of In2O3 thin Films Prepared by Sol-gel Method

Effect of precursor concentration, surfactant and temperature on the size, morphology and nanostructure of zero-valent iron nanocrystals synthesised by a polyol route

Iron metal nanoparticles, due to their magnetic properties, reducing power and low toxicity, have numerous applications not only in groundwater and contaminated soil remediation but also in biomedicine as contrast agents in magnetic resonance imaging. However, obtaining this nanomaterial involves the use of strongly reducing, polluting and expensive reagents and high temperatures. Herein, the use of ethylene glycol and diethylene glycol in a strong alkaline medium that allows the direct reduction of iron(II) salts to iron(0) in the absence of any added reducer has been analysed for preparation of well-defined nanoparticles. The key roles of the polyhydroxylated surfactants (D-mannitol, D-mannose, polyvinyl alcohol and polyvinyl pyrrolidone) were identified, and their efficiencies were evaluated. In addition, conclusions have been drawn regarding the existence of a minimum temperature required for the reduction of the precursor, as well as the observation that the size of the nanoparticles increases with reaction temperature. The main result is that by combining surfactants and controlling the reaction temperature, pure cubic iron(0) nanoparticles smaller than 100 nm were obtained, thereby reducing the formation of hydroxylated by-products. The high reactivity, high magnetic response, long-term stability and small size of the iron nanoparticles produced in this work will allow their use in various applications.

Investigating the effect of the perturbation on emulsion polymerization of polystyrene nanospheres

Polystyrene nanospheres (PS spheres) were prepared by soap-less emulsion polymerization. The polymerization reaction with the monomer styrene was initiated using potassium persulfate under nitrogen injection. By adjusting the amount of precursor and the mixing speed of the stirrer during the polymerization process, PS particles of the expected appropriate size can be obtained. This work focuses on the effect of precursor concentration, reaction conditions and stirrer speed on particle size. Samples (C1–C6) were systematically prepared with varying amounts of K2S2O8 and C8H8. The particle sizes ranged from 69.9[Formula: see text]nm to 364.44[Formula: see text]nm. The calculated K2S2O8 to C8H8 ratio remained approximately constant across the samples. This supports the observed trend where increasing monomer concentration leads to larger particle sizes, indicative of bonded spheres. In addition, a correlation between stirring speed and PS bead size is found, with higher speeds resulting in smaller particles. Transmittance analysis of the filtered and sieved process samples showed that better polymerization conditions could be selected for PS beads up to 220[Formula: see text]nm at a stirring speed of 900[Formula: see text]rpm.

Influence of surface passivation by MgO on photovoltaic performance of SnO2 based dye-sensitized solar cells

The study highlights effect of surface modification of SnO2 photoelectrode by MgO coating on photovoltaic properties of dye-sensitized solar cells (DSSCs). A thin coating of MgO on SnO2 photoelectrode was prepared using sol-gel-derived dip coating technique. The bare SnO2 and MgO coated SnO2 composite photoanodes was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS) and UV–vis spectrophotometer. The optical absorption study revealed that the modification in SnO2 by MgO coating caused an increase in absorption by photoanode in visible region. The solar cell was demonstrated by preparing FTO|SnO2|Dye|MgO|Electrolyte|Pt coated FTO device structure and tested with current density-voltage (J-V) measurement. The effect of precursor concentration of MgO coating on the performance of DSSCs were investigated. It was found that, optimized coating of MgO for 90 seconds on SnO2 improved all photovoltaic parameters, resulting in enhancement in efficiency by 42% compared to that of DSSC with bare SnO2 photoanode. The coating of MgO would have reduced the trap states and suppressed interfacial recombination losses by preventing back electron transfer from the conduction band of the semiconductor to HOMO of dye molecule or redox species.

Fast-dissolving calcium carbonate particles as a high-performance lime for amelioration of agricultural acidic soils

Effective soil management is essential for maximizing crop yields, as soil fertility plays a pivotal role in this process. Unfortunately, liming and fertilization practices are frequently ineffective, leading to overdoses and unnecessary product waste. Liming is essential for correcting soil acidity, mitigating aluminum toxicity, and promoting nutrient bioavailability before fertilizer application. This study explores the potential of vaterite, a highly soluble CaCO3 polymorph, as a sustainable liming agent. Vaterite particle synthesis is challenging because of its poor stability and rapid phase transformation into calcite, therefore, we analyze the effects of precursor concentration, Ca2+/CO32- ratio, and stirring rate on vaterite morphology and content in a reactive precipitation process through screening and D-optimal experimental designs, resulting in a design space to tailor the conditions that promote vaterite particles with a high dissolution profile at the lowest possible cost. To assess the efficacy of fast-dissolving CaCO3 particles, a comparative incubation test was conducted in andisol-type soil with a high buffering capacity. The results demonstrated that vaterite particles were capable of quickly adjusting the soil pH in the first few days using 360% fewer conventional liming agents. This innovative strategy aligns with Precision Agriculture principles, enabling efficient crop production while minimizing the environmental impact.

The Effect of Precursor Concentration on the Crystallite Size of CeO2 to Enhance the Sulfur Resistance of Pt/CeO2 for Water Gas Shift

To develop customized sulfur–resistant catalysts for the water gas shift (WGS) reaction in the waste–to–hydrogen process, the effects of changing the nucleation conditions of the CeO2 support on catalytic performance were investigated. Supersaturation is a critical kinetic parameter for nuclei formation. The degree of supersaturation of the CeO2 precipitation solution was controlled by varying the cerium precursor concentration from 0.02 to 0.20 M. Next, 2 wt.% of Pt was impregnated on those various CeO2 supports by the incipient wetness impregnation method. The prepared samples were then evaluated in a WGS reaction using waste–derived synthesis gas containing 500 ppm H2S. The Pt catalyst supported by CeO2 prepared at the highest precursor concentration of 0.20 M exhibited the best sulfur resistance and catalytic activity regeneration. The sulfur tolerance of the catalyst demonstrated a close correlation with its oxygen storage capacity and easier reducibility. The formation of oxygen vacancies in CeO2 supports is promoted by the formation of small crystals due to a high degree of supersaturation.

Effect of molar concentration on optoelectronic properties of NiO nanoparticles for p-n junction diode application

In this work, fine nickel oxide nanoparticles (NiO NPs) were successfully made utilizing a straightforward co-precipitation approach at low temperature. The effects of precursor concentration on the structural, optical, and electrical characteristics of NiO nanoparticles were investigated. All indexed diffraction peaks in XRD demonstrate the production of NiO with cubic structure. An increase in NiO crystallite size above 16.8 nm was observed when the precursor concentration exceeds 2 M, suggesting the presence of nanostructure in the final product. In FT-Raman spectra, the band centered at ∼ 500 cm–1 is due to Ni-O stretching (LO) mode, and two-magnon (2 M) scattering mode causes the band at 1514 cm–1. The synthesized product is composed of almost rod-shaped particles with a size range of 10–20 nm, according to FESEM pictures. The UV absorption studies showed a high absorption at the fundamental absorption edges originating at 332 nm, which gradually shifted to a lower energy region up to 400 nm with increasing precursor concentration, which means a reduction in bandgap values. The effect of precursor concentration associated with the electrical characteristics of the produced NiO nanoparticles has been investigated for the temperature range 30 to 130 °C. The I-V characterization was used to compute the different photo-diode parameters including n, ФB, Io, PS, R, QE, and D* . The remarkable high photosensitivity of 1100% and specific detectivity of 4.324 × 10−10 Jones for the diode evaluated at 120 mW/cm2 was observed in a 2 M fabricated diode. These findings imply that all the fabricated diodes are exceptionally light-sensitive and are well-suited for upcoming UV photodetector applications.

The effect of precursor concentrations on the structure and optoelectronic properties of quasi low-dimensional hybrid 2-methylpyridinium lead bromide crystalline phases

This work presents the synthesis and optoelectronic properties of the crystalline phases [Pb2Br5][C6NH8] and [PbBr3][C6NH8] of 2-methylpyridinium lead bromide.

Microfluidic-Aerosol Hyphenated Synthesis of Metal-Organic Framework-Derived Hybrid Catalysts for CO2 Utilization.

A new and efficient technique is developed by combining the hyphenated microfluidic- and aerosol-based synthesis with the coupled differential mobility analysis for the effective and continuous synthesis and simultaneous analysis of metal-organic frameworks (MOFs)-derived hybrid nanostructured products. HKUST-1, a copper-based MOF, is chosen as the representative to fabricate Cu-based hybrid catalysts for reverse water-gas shift (RWGS) reaction, an effective route for CO2 utilization. The effect of precursor concentration and carrier selection on the properties of the resulting products, including mobility size distribution, crystallization degree, surface area, and metal dispersion are investigated, as well as the correlation between the material properties of the synthesized catalysts and their catalytic performance in RWGS reaction in terms of conversion ratio/rate, selectivity, and operational stability. The results indicate that the continuous microfluidic droplet system can successfully synthesize MOF colloids, followed by the continuous production of MOF-derived hybrid materials through the tandem aerosol spray-drying-reaction system. High catalytic activity and low initiate temperature toward RWGS (turnover frequency = 0.0074s-1; 450°C) are achievable. The work facilitates the production and the designed concept of relevant MOF-derived hybrid nanostructured catalysts in the continuous synthesis system and the enhancement of applications in CO2 capture and utilization.

Pengaruh Konsentrasi Perkursor terhadap Sifat Listrik dari Lapisan Tipis

A thin layer is a layer made from organic or non-organic materials which are semiconductors, conductors and insulators. This research aims to determine the effect of precursor concentration on the electrical properties of thin films. Variations in precursor concentration used were 0.025 M, 0.05 M, and 0.075 M. CuSnO3 thin films were characterized by UV-DRS, XRD, FPP, and SEM. The method used in this research is sol-gel. The sol-gel process is used because of its ability to control the surface properties of oxide composites. The results of the band-gap test the variation in precursor concentration obtained by the band-gap value becomes smaller with increasing concentration. The lowest band-gap value in variations in adding an MEA volume of 2 ml, the optimum band-gap value is 2.1706 eV. The results of the FPP test on a thin layer of CuSnO3 precursor concentration of 0.05 M with an optimum MEA of 2 ml obtained a resistivity value of 0.0005671 Ωm with a conductivity value of 173.5809 Ω^(-1) m^(-1).

Effect of precursor concentration on the electrochemical properties of nickel cobalt phosphate for high-performance electrochromic supercapacitors

This research focuses on developing a high-performance electrode material for sustainable energy applications. The study explores the electrochemical deposition of a nickel-cobalt phosphate composite (NCPC) on a conductive glass substrate. A systematic investigation is conducted to analyze the influence of precursor concentrations, including nickel chloride hexahydrate (NiCl2·6H2O), cobalt chloride hexahydrate (CoCl2·6H2O), and disodium hydrogen phosphate (Na2HPO4), on the electrochromic and energy storage properties of NCPC. Utilizing Design Expert (DoE) software, the optimization process results in a predictive quadratic model with a residual standard error below 5 %, effectively capturing the relationship between independent variables and specific capacitance (Csp). Under optimized conditions (0.1 M NiCl2·6H2O, 0.3 M CoCl2·6H2O, and 0.4 M Na2HPO4), NCPC exhibits remarkable attributes, including a high Csp of 878 F/g (equivalent to 439 mAh/g) for energy storage and an impressive coloration efficiency of 62 cm2/C for electrochromic applications. These exceptional outcomes are attributed to the synergistic effects of NCPC, enhancing electrical conductivity, active site availability, and surface area, collectively contributing to superior electrochemical performance. An electrochromic energy storage device (NCPC//AC) is made, utilizing the optimized NCPC as the positive electrode and activated carbon (AC) as the negative electrode. The NCPC//AC device demonstrates notable performance features, including a high Csp of 135 F/g at a 5 mV/s scan rate, specific power of 750 W/kg, and specific energy of 11 Wh/kg, showcasing an exceptional power-to-weight ratio. Moreover, the NCPC//AC device exhibits excellent stability, retaining 78 % of its capacitance after 5000 charge-discharge cycles, highlighting its durability and long-term viability. In summary, this study emphasizes the exceptional electrochemical properties and performance of the NCPC//AC device, positioning it as a promising sustainable energy technology aligned with SDG 7 of ensuring access to affordable, reliable, sustainable and modern energy for all.

Tweaking and collating the structural, optical and magnetic properties of auto combusted lanthanum ferrites - study on effect of precursor concentration

A novel sol-gel auto-combustion technique is utilized to prepare nano-sized, perovskite-structured LaFeO3 powders. The nanoparticles were synthesized for three distinct precursor concentrations (0.5, 1 and 1.5 M) maintaining pH, annealing temperature and time. The synthesized nanoparticles were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, high-resolution scanning electron microscopy (HRSEM), high-resolution transmission electron microscopy (HRTEM), energy dispersive X-ray absorption spectroscopy (EDAX), diffuse reflectance spectroscopy (DRS), photoluminescence (PL) study and vibrating sample magnetometer (VSM). XRD revealed that all the prepared samples have shown an orthorhombic phase with space group Pnma. DRS suggested a marginal increase in bandgap and the average band gap was found to be 2.2 eV VSM analysis has shown that all the prepared samples exhibit weak ferromagnetic behaviour due to uncompensated canted spins. All the studies performed revealed a significant modification of structural, optical and magnetic properties with the variation of precursor concentration.

Probing the effect of precursor concentration on the growth and properties of titanium dioxide nanocones for environment safe solar cells.

Environment friendly third-generation solar cells sensitized by dyes, quantum dots, and perovskites are seen as promising energy alternatives. Among the various strategies, employing one-dimensional nanostructures that exemplify the smallest dimension for efficient carrier transport rate from the active layer to electron transport layer (ETL) in photovoltaic devices is attempted in this work. We herein report the synthesis of well-aligned 1-D TiO2 nanocones as ETL for photovoltaic thin films by varying the precursor concentration (0.03M, 0.04M, 0.05M) to track the evolution of growth. The hydrothermal approach is exploited to grow oriented rutile TiO2 nanocones on fluorine doped tin oxide (FTO) under neutral conditions. The examination of phase, crystallinity, morphology, and opto-electronic properties of the well-structured nanocone arrays is characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), ultra violet diffuse reflectance spectroscopy (UV-DRS), Brunnauer-Emmett-Teller (BET) surface area analysis, and field-dependent dark and photoconductivity analysis. The XRD pattern confirms the formation of the tetragonal rutile phase. SEM micrographs and UV-DRS spectroscopy reveals that the length of the nanocones and the energy gap is found to be maximum for 0.04M concentration with a well-defined excitation band at 316nm. Significantly, a strong light-trapping effect that decreases the incident light reflections and correspondingly increases the light absorption is unveiled through photoconductive studies for the TiO2 nanocones at 0.04M having a surface area of 81.767 m2/g. The investigation essentially suggests that the as-prepared one-dimensional nanostructures would serve as efficient photoanodes in environment safe third-generation solar cells.

The effect of precursor concentration on the crystallinity synchronization of synthesized copper nanoparticles

Highly crystalline copper nanoparticles are formed with Chemical Reduction Method (CRM) by the application of an effective capping agent and changing the precursor concentration. In this study, copper sulphate pentahydrate is used as a precursor which is reduced by ascorbic acid. The synthesized nanoparticles are designated as P, Q and R. These are systematically characterized by X-ray Diffraction (XRD), UV–Visible Spectroscopy (UV), Differential Scanning Calorimetry (DSC), Thermo-gravimetric Analysis (TGA), Transmission Electron Microscope (TEM) coupled with Energy Dispersive X-ray Spectroscopy (EDS). XRD ensured that the crystalline phase gradually changes from 79% to 96% with the change in precursor concentration from 0.08 M to 0.10 M. UV analysis shows that due to the high conductivity of copper nanoparticles might have caused the redshift at 630–634 nm. TGA show the energy of activation (Ea) of P is 22.90 KJ/mol which is more reactive than Q and R. An excellent arrangement in XRD and TEM confirms the average particle size near about 40 nm, with consists of crystal plane (111), (200) and (220). SAED confirmed the particles are elongated with the miller indices of the synthesized nanomaterials on (111), (200) and (220) planes. The EDS confirmed the purity of nanomaterials up to 86%. The adopted process may be employed to synthesize and synchronize the crystallinity of other metal nanoparticles.

Effect of precursor concentration on structural and optical properties of nickel oxide nanoparticles synthesized by facile sol-gel method

We report a simple, fast and efficient sol-gel technique to synthesize nickel oxide (NiO) nanoparticles of variable sizes. For this, three different precursor concentrations, viz. 0.1, 0.3, and 0.5 M were used. All the samples were maintained at a pH of 8 and calcined at 500 °C for 4 h. Our study shows the formation of well-crystalline, spherical, single-phase, pure NiO nanoparticles. The size of the nanoparticles increases with the concentration of the precursor solution. All nanoparticles show absorption peaks at the wavelength of ∼358 nm, which lie in the UV region and a near band edge emission peak at ∼390 nm.

Photoluminescence analysis of CsPb2Cl5 and CsPbCl3 perovskite films doped with Yb3+ deposited by aerosol-assisted CVD

Low-dimensional all-inorganic metal halide perovskites (MHPs) have attracted attention due to their promising advantages as semiconductor materials for optoelectronic applications. However, obtaining a low-dimensional MHPs pure phase has been difficult due to its high ionic nature. Here, the one-step in-situ deposition of CsPb2Cl5 films by Aerosol Assisted Chemical Vapor Deposition (AACVD) is reported for the first time. An analysis of the effects of precursor concentrations, using ethanol (EtOH) as antisolvent, and Yb3+ doping on the resulting three-dimensional and/or two-dimensional perovskite phase films is presented. It was found that a lead rich precursor (PbCl2:CsCl = 2:1) was necessary to promote the formation of the CsPb2Cl5 phase, in addition, the use of EtOH and doping with hetero-valent Yb3+ ions was required to attain this phase successfully. The excitation and emission photoluminescence spectra analysis for these films is focused on the three principal emissions: i) a narrow emission peak around 418 nm from the CsPbCl3 phase, ii) a dual broad emission around 550 nm from the CsPb2Cl5 phase, and iii) an emission at 984 nm associated with the Yb3+ ions introduced as dopants in the MHPs lattice. A possible mechanism is proposed for the observed energy transfer from the CsPb2Cl5 matrix to the ytterbium ions and for the interactions between Yb3+ and the excitonic emissions.

Synthesis of NiCo2O4 microflowers by facile hydrothermal method: Effect of precursor concentration

In this work, NiCo2O4 microflowers are developed via hydrothermal method. The impact of precursor concentration on morphology and supercapacitor performance is investigated. The XRD, FTIR and XPS study reveals the formation of NiCo2O4. The FE-SEM study shows the formation of microflower-like morphology. The NiCo2O4 with molar ratio Ni:Co = 1:2 exhibited a BET specific surface area of 147.3 m2 g−1. The supercapacitor study confirms the optimized NiCo2O4 electrode showed a maximum sp. capacitance of 747.4 F g−1 at 5 mV s−1. It exhibited highest energy density of 9.27 Wh kg−1 (@55.55 W kg−1) and 82.32% capacity retention over 5000 cycles.

The beneficial effect of reducing agent on the synthesis of manganese oxide nanowires as electrode materials for supercapacitors

We examine the effects of precursor concentration and changes in the volume of reducing agent on the physico-chemical properties and electrochemical performance of the manganese oxide materials. Despite the fact that studies have been published on the usage of ethylene glycol as a reducing agent in the preparation of manganese oxide, there is no report on the investigation of the change in concentration of the precursor and volume of the reducing agent and how it impacts the physical, chemical, and electrochemical properties of the end products. Hence, the present work attempts to attain knowledge of the found research gap. Three different concentrations of precursor, viz. 0.1, 0.25, and 0.5 M, and four different volumes of reducing agent, viz. 0.5, 1, 3, and 5 ml, are studied. Crystallinity, morphology, chemical state, and surface area characteristics of the prepared samples are thoroughly studied using a variety of techniques. There is an increment in crystallinity and a significant change in morphology observed from nanowires to agglomerated nanostructures when the volume of reducing agent linearly increases. Interestingly, the results indicate that a lower volume of reducing agent can facilitate the development of an end product with optimum electrochemical properties for supercapacitor applications. The samples prepared with a minimum volume of reducing agent achieve a high specific surface area of 241 m2/g with a noteworthy specific capacitance of 179 F/g and also show an acceptable capacitance retention of 74.2% even after 5000 consecutive cycles. These findings might develop a favorable impact and understanding on the ratio of reactants that can be utilized in various material preparations.