Wet Chemical Technique Research Articles

Utilization of marine snails for the sustainable synthesis and crystallographic characterization of nano-crystallite hydroxyapatite

In the present investigation, several biogenic sources of calcium were used to produce HAp nanomaterials by the use of a typical wet chemical precipitation technique. To determine the development of HAp nanocrystals, a variety of characterization methods were used, including X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared (FT-IR) spectroscopy. The results of XRD were used to evaluate a wide range of factors related to structure, such as lattice parameters, degree of crystallinity, dislocation density, microstrain, crystallinity index, and preference growth. The crystallite size of the produced HAp crystals was calculated using the equations of different models. Each of the formed HAp exhibits crystal arrangements that are within the allowed range of 1–150 nm, which the aforementioned models were used to figure out from the XRD information. Furthermore, the EDX examination (Ca, P, and O percentages) and Rietveld refinement (about 95% HAp) verified the makeup of the resultant HAp particles.

High entropy alloys mediated formation of multi-oxide nanoparticles on carbon fiber cloths and their synergistic effects in electrochemical performance

A wet chemistry technique is developed to produce high entropy alloy nanoparticles on carbon fibers. Coatings display solution phase and can be aerially oxygenated into multi-oxides. Electrochemical measurements confirm the generation of high specific capacitance from multi-oxide coatings where individual components show redox reactions at different potentials thus producing large loops of charge–discharge. Comparative study confirms synergistic effects arising from individual oxides in coatings.

Multifunctional Applications of Gd‐Doped ZnO Nanoparticles Prepared Easily by the Coprecipitation Method

AbstractThe present work involves the preparation of pure ZnO and gadolinium‐doped ZnO nanoparticles with the general formula GdxZn1−xO (X = 0–0.05) by wet chemical coprecipitation technique. XRD outcomes confirmed that these nanoparticles exhibited a hexagonal wurtzite structure of zinc oxide lacking any secondary phase. The calculated average crystallite size declined from 33 to 28 nm. Through SEM analysis, the shape and morphology of the sample were determined, which showed nanoflakes‐like structures, and EDS analysis confirmed the elemental composition of Gd‐doped ZnO nanoparticles. UV–vis DRS spectral studies indicate good optical capabilities with a decline in the bandgap from 3.4 to 2.6 eV with an incline in doping concentration. Photoluminescence studies exhibited a green emission peak at 378 nm. Additionally, photodegradation of these nanoparticles was assessed through degradation of MB dye, which showed 94% of dye degradation. Synthesized nanoparticles show good electrochemical performance in CV studies. Pure ZnO and Gd‐ZnO were examined against Gram‐positive Enterococcus faecalis and Gram‐negative Escherichia coli bacteria, and it was initiated that the zone of inhibition of antibacterial activity improved with gadolinium doping compared to the pure ZnO nanoparticles.

Effects of long-term nitrogen and phosphorus fertilization on soil phosphorus forms and dynamics under continuous wheat production in Saskatchewan, Canada

Many agricultural crops require both nitrogen (N) and phosphorus (P) fertilizers to sustain crop yields. However, long-term application of NH4–N fertilizers can cause soil acidification, which alters soil abiotic and biotic processes, including soil P dynamics. Long-term continuous wheat plots in Saskatchewan, Canada, were used to assess effects of N and P fertilization from 1967 and P fertilizer cessation in subplots from 1995. General soil chemical properties and soil P pools and forms were determined and then correlated with soil pH, total N (TN), and total P (TP) concentrations to show the relative importance on soil P dynamics of (a) crop nutrition (TN and TP); (b) soil acidification (pH); or (c) P fertilization/cessation. Fertilization with NH4–N decreased soil pH and altered exchangeable cation concentrations; however, long-term crop growth was poor in no-N plots and was best with both N and P fertilizers, in turn increasing soil carbon and organic matter. Applying P fertilizers without N increased soluble phosphates and the risk of P losses in runoff. Soil organic P (TPo) concentrations were correlated negatively to pH and positively to TN, but the concentrations of P compounds were not correlated to pH. This suggests that TPo accumulation may be from increased long-term crop residue inputs from crops with N and P fertilizers, rather than increased sorption from reduced pH. However, soil pH will continue to decrease with continued NH4–N fertilization, affecting soil chemistry and future P cycling; monitoring with a suite of wet chemistry and spectroscopic techniques is recommended.

Magnetically separable quaternary g-C3N4/Fe3O4/AgBr/rGO nanocomposite for enhanced photocatalytic degradation of ofloxacin in water under visible light irradiation

Novel photocatalytic-magnetic hybrid quaternary nanocomposite (g-C3N4/Fe3O4/AgBr/rGO) was successfully synthesized for the first time via ultrasonication-assisted wet chemistry technique. The nanocomposite was characterized using various advanced characterization techniques and its visible photocatalytic performance was analyzed by using ofloxacin (OFL) as target pollutant. The photocatalytic degradation efficiency was 100 % under conditions (pH 6.65, 0.1 g/L nanocomposite and 10 mg/L OFL) in 5 h. The pseudo-first-order kinetic constant of g-C3N4/Fe3O4/AgBr/rGO was as high as 1.1832 h−1. Evaluation of different catalysts, catalyst dosage, initial concentrations of OFL and initial solution pH have been studied. Based on the scavenging tests, benzoquinone (BQ) significantly decreased the removal efficiency of OFL to 41.4 %, indicating that O2− served as the dominant radical involved in the reaction. More importantly, after undergoing five cycles, the g-C3N4/Fe3O4/AgBr/rGO nanocomposite demonstrated robust stability and was effectively separated from the solution through magnetic means. The remarkable performance of g-C3N4/Fe3O4/AgBr/rGO is linked to substantial utilization of visible light and facilitation of Z-scheme heterojunctions, thereby facilitating charge separation. The quaternary nanocomposite exhibits auspicious potential for effectively degrading emerging organic pollutants and has bright application forecast for practical application in wastewater treatment.

Investigating the synergistic effect of Nd3+ and Ni2+ in CuO nanocrystals on their structural, optical, and magnetic properties for photovoltaic and photocatalytic implementations

The wet chemical precipitation technique was used to synthesize CuO, Nd:CuO and Ni-Nd:CuO nanoparticles efficiently. The produced substance was tested using X-ray diffraction (XRD) for confirming the crystallite structure, and scanning electron microscopy (SEM) was used to examine the morphological properties of the produced materials. Crystal defects and optical properties of the synthesized samples were analyzed through luminescence (PL) investigations and UV–Vis spectroscopy. EIS spectrum was utilized to study the electrochemical behavior of the prepared material. Vibrating Sample Magnetometer (VSM) was employed to examine the magnetic properties influencing from the doping of Ni2+ and Nd3+ ions into CuO, attributed to their substantial magnetic moment and ferromagnetic traits. Photovoltaic efficiency of the prepared material was studied by J-V characteristics and photon-to-electron converting efficacy (IPCE) studies. Photocatalytic properties were studied by degrading MB and RhB dyes. The enhancement in the photocatalytic performance of the Ni-Nd:CuO was a result of suppression of photogenerated electron-hole pair recombination and accelerated separation and migration of photogenerated charges.

Microwave digestion method for sulfide analysis of Çanakkale region coal

ABSTRACT Quantitative analysis of sulfide content in coal is a necessary step for complete analysis. Conventional analysis methods take several days, whereas it takes a few hours in microwave digestion method. In the present study, a new wet chemical analysis technique was developed and applied to quantify the sulfide content in Turkish coal samples. In the initial step, 5 M HCl solution is employed to dissolve the sulfate phases present in the coal. Subsequently, pyrite is separated from the residue obtained in stage 1 through the utilization of 2 M HNO3 solution. The final stage involves the determination of organic sulfur, wherein concentrated HNO3, HCl, HF, and boric acid are utilized to completely decompose the remaining residue from stage 2. The extracted solutions from each stage are promptly analyzed for sulfur content using ICP-OES. The cumulative values of the three sulfur forms consistently correspond with certified total sulfur data for the majority of the examined coals. Among several advantages, the analysis duration is the most distinctive feature. Chemical analysis of sulfide in coal with microwave analysis method completed three times rapid than with conventional analysis.

Activated carbon based TiO2 nanocomposites (TiO2@AC) used simultaneous adsorption and photocatalytic oxidation for the efficient removal of Rhodamine-B (Rh–B)

The availability of fresh water is limited compared to its huge consumption. Conversely, certain industries like dyes, textiles, paper, and tanning not only consume vast quantities of fresh water, but also generate significant amounts of wastewater that poses severe threats to living organisms. The present investigation focuses on the degradation of Rhodamine-B (Rh–B) as a model pollutant by using the nanocomposite based on waste scrap tire-derived activated carbon (AC) and titanium dioxide (TiO2). These nanostructures were fabricated using wet chemistry techniques. Analysis using scanning electron microscopy (SEM) revealed that the morphology of the structures remained largely unchanged even with a concentration of 6 mg of AC. X-ray diffraction (XRD) results confirmed the successful fabrication of rutile and anatase phases of TiO2@AC nanocomposite. The XPS results confirmed the presence of AC and TiO2 in the composite. Furthermore, the optical band gap of the nanocomposites decreased up to 17.17 % and 34.57 % through direct and indirect methods respectively, owing to the varying quantity of AC used. The narrowing of optical band gap and the increased surface oxygen vacancies were caused by the successive addition of AC during the synthesis of nanocomposites. This resulted in the efficient degradation of Rhodamine-B (Rh–B) using adsorption and photocatalytic oxidation. The findings demonstrate a significant influence of AC on the TiO2 catalyst in the removal of Rh–B dye. The maximum efficiency of dye removal, reaching up to 99.14 %, was achieved with the highest concentration of AC, thus demonstrating almost complete elimination of Rh–B dye. The findings suggest that the use of waste scrap tires can be effectively applied to design efficient photocatalysts for addressing the wastewater management issues.

Environmentally friendly p-type CTS-based thin-film thermoelectric generator

Cu-based sulphides are promising materials for environmentally friendly Te-free thermoelectric generators (TEGs). Cu2SnS3 (CTS) stands out for its electronic properties, stemming from its conductive Cu–S networks, especially in fully disordered cubic structural form. While wet chemical techniques are the most utilized for CTS synthesis, they introduce organic contaminants that reduce electronic connectivity between grains, limiting their performance as in-plane thin-film TEGs. We present a new method to improve the electronic properties of CTS thin films for thermoelectric applications involving three-step dry route synthesis of ball milling, thermal evaporation, and sulfurization of Cu2–Sn metallic precursors. Via this method, charge carrier concentration increased significantly, as estimated by Hall effect analysis, which was attributed to the Cu-poor stoichiometry, also confirmed via energy-dispersive X-ray spectroscopy (EDXS). Microstructural analysis by scanning electron microscopy (SEM) revealed micrometre-sized grains composed of even smaller crystalline domains, which X-ray diffraction (XRD) showed to be ~ 50 nm in diameter. When compared with literature results, our procedure leads to a fourfold enhancement in the thermoelectric power factor (PF=S2σ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$PF={S}^{2} \\sigma$$\\end{document}), determined through the Seebeck coefficient measurements (S\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$S$$\\end{document}) and electronic conductivity (σ) estimated by the van der Pauw technique. The CTS TEG has a power volume density of 2.3 μW K−1 cm−3, measured by a custom current–voltage–power (I–V–P) setup with varying load resistance. Results present a 100% increase in performance compared to ink-based techniques and were reproducible across three different batches. This strategy, improving the density of the CTS thin films, offers a new way to enhance Cu-based thin-film TEGs.

Studying the Anti-microbial and Alpha Amylase Inhibition Activity of Cerium Oxide Nanoparticles for Biomedical Applications

Cerium oxide nanoparticles (CNP) have been produced using a wet chemical technique. The therapeutic capacities of cerium oxide nanoparticles are determined based on the analysis of their anti-diabetic and antibacterial activities. The study below demonstrated the antibacterial characteristics of cerium oxide nanoparticles (CNP) against several bacteria. Specifically, the inhibition zones observed for Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Enterococcus gergovae were 14.5mm, 11mm, 17mm, and 15mm, respectively. The results obtained indicate that CNP has the potential to address the urgent problem of hospital-acquired microbial infections, particularly those caused by antibiotic-resistant microorganisms. Additionally, the anti-diabetic property of CNP was evaluated and found to have a 66% alpha amylase inhibition, which suggests a significant reduction in glucose levels. Therefore, it has the potential to be utilized as an antidiabetic medication as well. The study has produced a compound with potent biological capabilities that can be enhanced through a synthesis technique and utilized in the pharmaceutical industry.

Strontium Oxide Functionalized Chitosan as Novel Bioaffinity Layer for Construction of Multipurpose Biosensor Platform

The wet chemical technique was used to create a biofriendly composite consisting of Strontium Oxide hybridized chitosan (SrO-CS). A spectroscopic analysis revealed that the CS amine group is mostly hybridized with the SrO nanoparticle. The crystalline phases of the nanoparticle are visible in the as prepared SrO-CS. Morphological studies show that the SrO nanorods are covered in CS flakes. The greater electron transfer rate is demonstrated by the SrO-CS modified GCE, which follows a surface confined mechanism at the interface. The SrO-CS modified screen-printed electrode was used to immobilize miRNA sequences in order to selectively detect exosomal CD24 oligonucleotides that are suitable for a broad spectrum of target analyte detection. For biosensor applications, the created SrO-CS functions as a useful bio-affinity layer for biomolecule attachment.

Subsurface damage evolution of β-Ga2O3 (010) substrates during lapping and chemical mechanical polishing

For semiconductor single crystal substrates, subsurface damage (SSD) is an important factor for device failure. For β-Ga2O3 with two cleavage planes, the SSD is the key issue that needs to be addressed. In this work, β-Ga2O3 (010) substrates were lapped and polished precisely. The formation and evolution mechanisms of SSD were analyzed by cross-section transmission electron microscopy and wet chemical etching techniques. The linear distribution of scratches was found on the substrates after lapping. After chemical mechanical polishing (CMP), the surface scratches were eliminated. However, the SSD layer may still exist under the surface. Chemical etching was developed to identify the "invisible damage" to the CMP-finished (010) substrate. The SSD including nanocrystalline, tilt boundary, twist boundary, and high-density dislocations in β-Ga2O3 was first reported. Distinctively, there was no slip occurrence in the SSD of the (010) plane different from the (100) and (001) planes. The Schmid factor of multiple slip systems was calculated to analyze the cause of no slip on the subsurface. The formation mechanism of SSD was believed that when the slip system could not be activated, the stress was released through rotation and distortion of the crystal plane. The accumulation of grain boundary dislocations at twist grain boundary junctions provided a driving force for the formation of nanovoids. The relationship of substrate damage evolution and crystal strain with different machining parameters was established by high-resolution X-ray diffraction and Raman spectra. A non-damaging β-Ga2O3 (010) substrate with a surface roughness of less than 0.2 nm was obtained by the optimized CMP process. The research results had guiding significance for damage control of β-Ga2O3 and other brittle crystals in ultra-precision machining.

Doped carbon dots reinforced flexible nanocomposite active polymer film for antibacterial and antioxidant activities

Utilizing nanoparticles in packaging materials has proven to be an effective method for enhancing the longevity and security of food products. Carbon dots (CDs) have a wide variety of potential applications in food packaging. A flexible film made of thermoplastic chitosan (TPC) and heteroatom-doped CDs has been created using a wet chemical blending technique. These CDs reinforced TPC based hybrid films exhibit flexibility, antioxidant properties, biodegradability, and resistance to UV radiation. The mechanical strength of the films was assessed through uniaxial tensile testing, while their low-temperature flexibility was evaluated by measuring the sub-ambient (∼-30°C) glass transition temperature (Tg). Additionally, the presence of CDs directly influences the permeability of oxygen and moisture, resulting in a reduction in comparison to neat chitosan films, a vital characteristic for packaging materials. Over a span of three weeks, the TPC-based hybrid films demonstrated a progressive weight loss (∼75 %), indicating their biodegradability. Furthermore, these films have shown promise as antibacterial and antioxidant materials. The durability of the films and the absence of chemical release from the embedded CDs within the TPC matrices were also verified, underscoring their considerable potential as antibacterial, biodegradable, and antioxidant packaging materials within the food industry.

A Complementary Multitechnique Approach to Assess the Bias in Molecular Weight Determination of Lignin by Derivatization-Free Gel Permeation Chromatography.

The growing interest in lignin valorization in the past decades calls for analytical techniques for lignin characterization, ranging from wet chemistry techniques to highly sophisticated chromatographic and spectroscopic methods. One of the key parameters to consider is the molecular weight profile of lignin, which is routinely determined by size-exclusion chromatography; however, this is by no means straightforward and is prone to being hampered by considerable errors. Our study expands the fundamental understanding of the bias-inducing mechanisms in gel permeation chromatography (GPC), the magnitude of error originating from using polystyrene standards for mass calibration, and an evaluation of the effects of the solvent and type of lignin on the observed bias. The developed partial least-squares (PLS) regression model for lignin-related monomers revealed that lignin is prone to association mainly via hydrogen bonding. This hypothesis was supported by functional group-based analysis of the bias as well as pulse field gradient (pfg) diffusion NMR spectroscopy of model compounds in THF-d8. Furthermore, although the lack of standards hindered drawing conclusions based on functionalities, direct infusion electrospray ionization mass spectrometry indicated that the relative bias decreases considerably for higher molecular weight species. The results from pfg-diffusion NMR spectroscopy on whole lignin samples were comparable when the same solvents were used in both experiments; in addition, the comparison between results obtained by pfg-diffusion NMR in different solvents gives some additional insights into the aggregation.

Chemical Bath Deposition of ZnO/ZnGa2O4 Core-Shell Nanowire Heterostructures Using Partial Chemical Conversion.

The development of innovative heterostructures made of ZnO nanowires is of great interest for enhancing the performances of many devices in the fields of optoelectronics, photovoltaics, and energy harvesting. We report an original fabrication process to form ZnO/ZnGa2O4 core-shell nanowire heterostructures in the framework of the wet chemistry techniques. The process involves the partial chemical conversion of ZnO nanowires grown via chemical bath deposition into ZnO/ZnGa2O4 core-shell nanowire heterostructures with a high interface quality following their immersion in an aqueous solution containing gallium nitrate heated at a low temperature. The double-step process describing the partial chemical conversion relies on successive dissolution and reaction mechanisms. The present finding offers the possibility to fabricate ZnO/ZnGa2O4 core-shell nanowire heterostructures at low temperatures and over a wide variety of substrates with a large surface area, which is attractive for nanostructured solar cells, deep-UV photodetectors, and piezoelectric devices.

XPS analysis of molecular contamination and sp2 amorphous carbon on oxidized (100) diamond

The efficacy of oxygen (O) surface terminations on diamond is an important factor for the performance and stability for diamond-based quantum sensors and electronics. Given the wide breadth of O-termination techniques, it can be difficult to discern which method would yield the highest and most consistent O coverage. Furthermore, the interpretation of surface characterization techniques is complicated by surface morphology and purity, which if not accounted for will yield inconsistent determination of the oxygen coverage. We present a comprehensive approach to consistently prepare and analyze oxygen termination of surfaces on (100) single-crystalline diamond. We report on x-ray photoelectron spectroscopy (XPS) characterization of diamond surfaces treated with six oxidation methods that include various wet chemical oxidation techniques, photochemical oxidation with UV illumination, and steam oxidation using atomic layer deposition (ALD). Our analysis entails a rigorous XPS peak-fitting procedure for measuring the functionalization of O-terminated diamond. The findings herein have provided molecular-level insights on oxidized surfaces in (100) diamond, including the demonstration of clear correlation between the measured oxygen atomic percentage and the presence of molecular contaminants containing nitrogen, silicon, and sulfur. We also provide a comparison of the sp2 carbon content with the O1s atomic percentage and discern a correlation with the diamond samples treated with dry oxidation which eventually tapers off at a max O1s atomic percentage value of 7.09 ± 0.40%. Given these results, we conclude that the dry oxidation methods yield some of the highest oxygen amounts, with the ALD water vapor technique proving to be the cleanest technique out of all the oxidation methods explored in this work.

Efficient and stable supercapacitors using rGO/ZnO nanocomposites via wet chemical reaction

The electrochemical behaviorof metal oxide nanoparticles (NPs) can be improved by maximizing the surface area and combining materials with high electrical conductivity. The reduced graphene oxide (rGO) enables to bestow a larger surface area for intercalation and deintercalation as well as shorter paths for ion transfer, lowering ionic resistance. In the current research, hybrid composites of rGO and zinc oxide (ZnO) NPs were successfully synthesized by using a wet chemical method for the application of supercapacitors. The wet chemical technique for industrial-scale nanocomposite synthesis is easy, fast, and cost-effective and requires no specialized equipment. The size, surface morphology, and crystalline structure of the rGO/ZnO nanocomposites were characterized by using FE-SEM, HR-TEM, and XRD, respectively. By using cyclic voltammetry and Galvanostatic charge–discharge tests, it was confirmed that the capacitances of rGO/ZnO composites were significantly enhanced compared to that of pure ZnO NPs. The proposed nanocomposite could achieve significantly enhanced specific capacitance (258 Fg−1) and also, it was able to achieve a longer life cycle with maximum capacitance retention. We expect that this work provides a simple but very effective strategy for the rGO and metal oxide NP composites.

Direct Synthesis of Calcium Lactate through the Reaction of Glycerol with Calcium Hydroxide Catalyzed by Bimetallic AuCu/SiO2 Nanocatalysts

Bimetallic AuCu/SiO2 nanosized catalysts were prepared using the wet chemical reduction technique. From among Au0.1–1.5Cu10/SiO2 catalysts, the Au0.5Cu10/SiO2 catalyst gave the highest yield of calcium lactate of 87% at a glycerol conversion of 96% when the reaction of glycerol with calcium hydroxide at a mole ratio of calcium hydroxide to glycerol of 0.8:1 was conducted under an anaerobic atmosphere at 200 °C for 2 h. The interactions between metallic Au0 and Cu0 nanoparticles facilitate calcium lactate formation. The simulation of glycerol consumption rate with an empirical power-function reaction kinetics equation yielded a reaction activation energy of 44.3 kJ∙mol−1, revealing that the catalytic reaction of glycerol with calcium hydroxide to calcium lactate can be conducted by overcoming a mild energy barrier. The synthesis of calcium lactate through the catalytic reaction of glycerol with calcium hydroxide on a bimetallic AuCu/SiO2 nanosized catalyst under a safe anaerobic atmosphere is an alternative to the conventional calcium lactate production technique through the reaction of expensive lactic acid with calcium hydroxide.

High performance of SrCo1-xZrxO3-δ perovskite cathodes for IT-SOFCs

Stabilization of a tetragonal perovskite structure in the SrCoO3-δ system at room temperature has been achieved through wet chemical techniques, and it has been successfully tested in Solid Oxide Fuel Cells (SOFCs). Chemical substitutions at the Co position were carried out by introducing different amounts of zirconium (SrCo1-xZrxO3−δ; x = 0.05, 0.08 and 0.11) to destabilize the columns of CoO6 octahedra sharing faces in the competitive 2H-hexagonal phase. The crystal structure was studied by X-ray diffraction (XRD) and neutron powder diffraction (NPD) at 25 °C and correlated with mechanical and electrical properties. Chemical compatibility studies between the samples and the La0.8Sr0.2Ga0.83Mg0.17O3-δ (LSGM) electrolyte revealed not interaction at high temperatures. Dilatometric analysis measurements showed a compatible thermal expansion with the LSGM electrolyte over the entire temperature range, demonstrating good mechanical compatibility. Furthermore, the relatively high conductivity values (∼83 S cm-1 at 850 °C) indicated their suitability as cathodes in SOFCs. Finally, test cells prepared with an electrolyte (LSGM) supported configuration provided a maximum output power exceeding 600 mW/cm2 using pure H2 as fuel at 850 °C. Importantly, the performance of the cathode materials did not degrade after extended operation at this temperature.

Lattice variation as a function of concentration and grain size in MgO–NiO solid solution system

The study aimed to understand how changes in crystal's size affect the lattice parameters and crystal structure of Mg1-xNixO solid solution for six X values ranging from x = 0 to x = 1. Mg1-xNixO was synthesized via two different wet-chemical techniques: the sol-gel and the microwave hydrothermal method, both followed by calcination at different temperatures of 673, 873, 1073, 1273 and 1473 K. As annealing caused grain growth, the varied temperature range allowed to examine a wide range of grain sizes. The lattice parameters and x values were determined from XRD (X-ray diffraction) peak positions and intensities respectively. The grain size was evaluated by XRD line profile analysis and supported by SEM (scanning electron microscope) observations. At the temperatures of 673 and 873 K grain size was in the nanometric range and from 1073 K and above grain size was in the micrometric range. A non-monotonic lattice variation versus grain size was found for each concentration. When grain size decreased there was a slight contraction, however for grain size in the nanometric range there was a severe lattice expansion. Both lattice parameter changes were explained by two effects acting together: contraction due to surface stress and expansion due to weakening of the ionic bonding at nanocrystalline particles. In this current research study, the lattice parameter was mapped in two dimensions: concentration and grain size. The findings of this study provided valuable insights into the lattice variation in the MgO–NiO solid solution system.