Amount Of Citric Acid Research Articles

Preparation and Characterization of Superabsorbents Based on Durian Seed Starch (Durio zibethinus) and Carboxymethyl Cellulose Using Citric Acid Crosslinking

Superabsorbents are materials that can absorb a liquid beyond its initial volume. Natural polymer-based superabsorbents can be obtained by combining CMC and durian seed starch. The combination of these two materials was cross-linked using varying amounts of citric acid: 0.0 grams, 0.2 grams, 0.4 grams, and 0.6 grams. The resulting superabsorbent has a cross-linking degree of about 41%, shows the presence of OH and CH groups, has a rough and dense surface, and a maximum water absorption capacity of 4130% with a water absorption rate of 41.3 g/g. Durian seed starch has potential as a superabsorbent material.

Validation of Enzytec™ Liquid Citric Acid for Enzymatic Determination of Citric Acid in Selected Foods and Beverages: First Action 2024.02.

Due to its excellent acidifier, antioxidant, and preservative properties, citric acid is added to or is a constituent in a broad range of foods and beverages. Its measurement should be performed to assure the food quality specifications are met. To validate the performance of the Enzytec™ Liquid Citric acid test kit for the determination in food and beverages such as wines, juices, and tomato products. The kit contains two ready-to-use components which makes handling very easy and suitable for automation. Citrate is cleaved into oxaloacetate and acetate by citrate lyase. Oxaloacetate reacts to L-malate by L-malate dehydrogenase and reduced nicotinamide adenine dinucleotide (NADH). Pyruvate, spontaneously formed from oxaloacetate, is converted by L-lactate dehydrogenase to L-lactate. The NADH consumed is equivalent to the amount of citric acid converted and is measured at a wavelength of 340 nm within 20 min. The test is specific to citric acid and shows no relevant interferences. Limit of detection and limit of quantification are 15 and 40 mg/L, respectively when using a test volume of 100 µL. The linear measurement range is from 40 to 1000 mg/L citric acid. Trueness was evaluated using materials from FAPAS, NIST, LGC, and two control wines from the German Wine Analysts. Matrix interference was evaluated by spiking tomato ketchup, tomato paste, orange juice and carbonated beverages and resulted in recoveries around 100%. Intermediate precision is between 6.2% and 8.5% for matrixes with extraction and below 4% for matrixes measured directly.For automation, three applications with different test volumes and different measurement ranges were validated. Linearity is given from 8 mg/L up to 5 g/L (depending on the test volume). The method is robust and accurate for manual and automated applications. The method was approved as AOAC Official Method of Analysis℠. The ready-to-use components of the test kit have a shelf life of at least 24 months from date of manufacture.

Citric acid production by Brazilian garlic Aspergillus welwitschiae strains using orange residues

The global production of citrus fruits has expressively grown resulting in large amounts of residue. Orange residues are rich in carbon and could be used as substrates for production of biomolecules such as citric acid. In this study, wild and mutant Aspergillus welwitschiae strains isolated from Brazilian garlic were used to produce citric acid from orange residues, using solid-state fermentation. The results showed that the mutant A. welwitschiae UELAs 15.262/35 produced great amount of citric acid in the fourth day of solid-state fermentation using total and reducing sugars and producing cellulases. On the other hand, there was no production of citric acid by wild A. welwitschiae UELAs 15.262. The use of total and reducing sugars and the production of cellulases by A. welwitschiae UELAs 15.262 were detected, suggesting the use of carbon sources for the production of other metabolites. The great use of reducing sugars and cellulases production by A. welwitschiae UELAs 15.262/35 indicated the consume of carbon sources from the orange residue to produce citric acid at early times of fermentation. These findings lead to the possibility of biotechnological valorization of orange residues for acid organic production by A. welwitschiae strain.

Enhanced Photocatalytic Activity of Direct Z‐Scheme K4Nb6O17/Carbon‐Rich Melon Heterostructures

AbstractMelon (also known as graphitic carbon nitride, g‐C3N4) holds promise for photocatalysis, but challenges such as severe charge recombination, low oxidation potential, and sluggish exciton dissociation hinder its performance. Herein, a series of carbon‐rich, melon‐based photocatalysts are synthesized via one‐pot, temperature‐induced condensation of urea with the addition of a trace amount of citric acid. The addition of citric acid enhances crystallinity, extends melon chains, increases the C/N ratio, and improves π–π layer stacking of heptazine units, thereby enhancing charge transport properties and visible‐light harvesting capacity. These carbon nitride samples are then coupled with molten salt synthesized K4Nb6O17 crystals by a straightforward self‐assembly method to construct 2D/2D heterostructure photocatalysts. Z‐scheme electron transfer from K4Nb6O17 to the melon samples is established based on their work functions and band edge positions. This efficient charge transfer in the Z‐scheme heterostructure facilitates the spatial separation of charge carriers, resulting in a nearly fivefold enhancement in photocatalytic performance compared to the individual constituents.

Tuning the composition of CuO/Cu2O composite powders via solution combustion method for supercapacitor application

In this work, the solution combustion synthesis method was implemented as a facile and in-situ procedure to adjust the composition of CuO/Cu2O composite by controlling the amounts of citric acid as fuel. Furthermore, the role of the Cu2O phase on the electrochemical properties was evaluated by preparation the single-phase CuO powders through calcination the CuO/Cu2O composite powders. The structural and microstructural results have shown that the synergic effects of Cu2O and CuO increased the electrochemical performance, including specific capacitance of 842 Fg−1 at 1 Ag−1 and high rate capability of 88 % by increasing the current density to 5 Ag−1. Furthermore, the CuO/Cu2O//activated carbon capacitor exhibited high electrochemical performance, such as an energy density of 27 Wh kg−1 at a power density of 1500 W kg−1 and outstanding cycling stability with 82 % capacitive retention for 2000 charge/discharge cycles, indicating a great potential for the practical application of CuO/Cu2O composite powders.

Mixture composition design of magnesium oxychloride cement-stabilized crushed stone materials applied as a pavement base

Conventional binding materials, such as silicate cement and lime, present high energy consumption, pollution, and carbon emissions. Therefore, we utilize crushed stone as a stabilization material. Magnesium oxychloride cement (MOC) is modified and used as an inorganic admixture owing to its eco-friendly nature and low carbon content. We analysed the control indicators of an integrated design of MOC-stabilized crushed stone by conducting unconfined compressive strength and water-resistance tests. The optimum mixing composition of the MOC-stabilized crushed stone was determined through the response surface methodology. We determined the best approach and dosage for improving the water resistance of MOC-stabilized crushed stone by comparing the effects of four modification methods: fly ash, citric acid + silica fume, phosphoric acid + waterborne polyurethane, and dihydrogen phosphate potassium salt. We also perform a comparison with 5% ordinary silicate cement-stabilized crushed stone. The results indicate that the MOC-stabilized crushed stone exhibits a rapid increase in strength in the early stage, but this rate reduces after 28 days. The mixing design employs the 4-day unconfined compressive strength and 1-day water resistance coefficient as the technical indicators. The best mixing composition includes a 4.27% MOC dosage and a molar ratio of MgO/MgCl2 of 5.85. We use 1% citric acid + 10% silica fume in equal amounts to replace the MOC dopant method for composite modification of the MOC stabilized crushed stone. Consequently, the 1-day water resistance coefficient before water immersion is significantly increased from 0.78 to 0.91 and its 4-day unconfined compressive strength is only reduced by 0.10 MPa. This significantly improves the water resistance of the MOC-stabilized crushed stone and ensures that its strength remains unaffected, which is the optimal modification method. However, this method must ensure that a small amount of citric acid and silica fume are uniformly distributed in the MOC-stabilized crushed stone, which increases the construction difficulty of the road base.

Towards scalable and degradable bioplastic films from Moringa oleifera gum/poly(vinyl alcohol) as packaging material

The use of plant gum-based biodegradable bioplastic films as a packaging material is limited due to their poor physicochemical properties. However, combining plant gum with synthetic degradable polymer and some additives can improve these properties. Keeping in view, the present study aimed to synthesize a series of bioplastic films using Moringa oleifera gum, polyvinyl alcohol, glycerol, and citric acid via thermal treatment followed by a solution casting method. The films were characterized using analytical techniques such as FTIR, XRD, SEM, AFM, TGA, and DSC. The study examined properties such as water sensitivity, gas barrier attributes, tensile strength, the shelf life of food, and biodegradability. The films containing higher citric acid amounts showed appreciable %elongation without compromising tensile strength, good oxygen barrier properties, and biodegradation rates (>95%). Varying the amounts of glycerol and citric acid in the films broadened their physicochemical properties ranging from hydrophilicity to hydrophobicity and rigidity to flexibility. As all the films were synthesized using economical and environmentally safe materials, and showed better physicochemical and barrier properties, this study suggests that these bioplastic films can prove to be a potential alternative for various packaging applications.

Citric acid crosslinked carboxymethyl cellulose edible films: A case study on preserving freshness in bananas

The study involves the preparation and characterization of crosslinked-carboxymethyl cellulose (CMC) films using varying amounts of citric acid (CA) within the range 5 %–20 %, w/w, relative to the dry weight of CMC. Through techniques such as Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, carbonyl content analysis, and gel fraction measurements, the successful crosslinking between CMC and CA is confirmed. The investigation includes an analysis of chemical structure, physical and optical characteristics, swelling behavior, water vapor transmission rate, moisture content, and surface morphologies. The water resistance of the cross-linked CMC films exhibited a significant improvement when compared to the non-crosslinked CMC film. The findings indicated that films crosslinked with 10 % CA demonstrated favorable properties for application as edible coatings. These transparent films, ideal for packaging, prove effective in preserving the quality and sensory attributes of fresh bananas, including color retention, minimized weight loss, slowed ripening through inhibiting amyloplast degradation, and enhanced firmness during storage.

Fruit Quality and Biochemical Characteristics of Different Strawberry Tree (Arbutus unedo L.) Genotypes Grown In Giresun

Fruit quality, chemical and biochemical properties of strawberry tree (Arbutus unedo L.) genotypes that naturally spread in Bulancak district of Giresun province were examined. In this context, as a result of examinations carried out on 20 genotypes subject to research were determined fruit weight 2.39-4.69 g, fruit width 16.85-20.62 mm, fruit length 14.52-17.29 mm, pH 3.36-3.88, SSC 11.60-19.60%. Glucose, sucrose, fructose and total sugars of water soluble sugars in arbutus genotypes were analyzed and respectively 2.32-8.34 g 100 g-1, 0.02-1.93 g 100 g-1, 3.08-17.93 g 100 g-1 and 7.47-27.51 g 100 g-1 values were obtained. The amount of vitamin C contained in the fruits of strawberry tree was determined as 13.53-126.60 mg 100 g-1, the amount of citric acid was 0.16-0.69% and the amount of malic acid was 0.27- 1.30%.

Thermal study of APTES-functionalized magnetite nanoparticles with citric acid and polyacrylic acid for advanced forward osmosis systems

Iron-based magnetic nanoparticles (MNPs) have attracted considerable attention as promising draw solutes in forward osmosis processes due to various advantages. In the present study, magnetite (Fe3O4) nanoparticles (MNPs) with diameters in the range of 12 ± 2 nm were synthesized by applying the coprecipitation method and stabilized using (3-aminopropyl)triethoxysilane (APTES). The amino groups of APTES were further functionalized with various amounts of citric acid (CA) and poly(acrylic acid) (PAA) to achieve higher osmotic pressure. The as-prepared and functionalized nanoparticles were characterized using different methods: Fourier-transform infrared spectroscopy (FTIR) confirmed the binding of APTES and CA/PAA on the surface of the MNPs, while the size of the particles was determined by transmission electron microscopy (TEM) and X-ray powder diffraction. The isoelectric point, zeta potential, and the particle size in suspension were determined by dynamic light scattering (DLS)/zeta potential measuring system. The amount of free –COOH groups was determined by conductometric titrations. The amount of organic matter (APTES, CA, and PAA) bound on the surface was determined by thermogravimetric analysis (TG), giving results between 7.6% for samples stabilized with APTES only and 17.5% for samples functionalized with APTES + PAA. TG provides a simple and efficient method for determining the amount of organic compounds bound to the surface of MNPs. The osmotic pressure measurements of double-layer coated MNPs provided encouraging results of up to 28 bar, enabling using the samples as draw solutions in an experimental forward osmosis system.

In2O3 crystal phase variation on In2O3/Co3O4 to boost CO2 hydrogenation to methanol

In2O3/Co3O4 catalysts with various crystal structure of In2O3 were successfully prepared by means of regulating the amount of citric acid, and were applied for CO2 hydrogenation to methanol to understand the structure-activity relationship. With the increase of citric acid content in the impregnation process, hexagonal In2O3 (h-In2O3) is gradually transformed into cubic In2O3 (c-In2O3). The interaction and electron transfer between c-In2O3 and Co3O4 are stronger than those between h-In2O3 and Co3O4. In the In2O3/Co3O4 catalysts prepared with citric acid, phase transformations were observed under reaction conditions of 4 MPa and 300 °C. Initially, h-In2O3 transitions into c-In2O3. Concurrently, there is a transformation of In2O3 and Co3O4 into metallic cobalt (Co0) and the compound Co3InC0.75. Except for h-In2O3/Co3O4 containing mixed h-In2O3 and c-In2O3, In2O3 in all other catalysts exists in the form of c-In2O3. Owing to stronger interaction between c-In2O3 and Co0, dissociated hydrogen atoms diffuse more easily from the metallic Co0 to c-In2O3 to produce more oxygen vacancies, accompanied with the formation of more inactive Co3InC0.75 (70 wt% for c-In2O3/Co3O4 vs 58 wt% for h-In2O3/Co3O4). However, h-In2O3/Co3O4 has stronger adsorption ability of CO to improve methanol selectivity. Thus, it can be observed that the CO2 conversion and methanol selectivity of the catalyst are directly related to the In2O3 crystal phase for In2O3/Co3O4 catalysts. To be specific, h-In2O3/Co3O4 has the higher selectivity of methanol, while c-In2O3/Co3O4 exhibits the higher conversion of CO2 and methanol space-time yield.

Overexpression of the DHA1 family, ChlH and ChlK, leads to enhanced dicarboxylic acids production in koji fungi, Aspergillus luchuensis mut. kawachii and Aspergillus oryzae

The white koji fungus Aspergillus luchuensis mut. kawachii secretes substantial amounts of citric acid through the expression of the citric acid exporter CexA, a member of the DHA1 family. In this study, we aimed to characterize 11 CexA homologs (Chl proteins) encoded in the genome of A.luchuensis mut. kawachii to identify novel transporters useful for organic acid production. We constructed overexpression strains of chl genes using a cexA disruptant of the A.luchuensis mut. kawachii as the host strain, which prevented excessive secretion of citric acid into the culture supernatant. Subsequently, we evaluated the effects of overexpression of chl on producing organic acids by analyzing the culture supernatant. All overexpression strains did not exhibit significant citric acid accumulation in the culture supernatant, indicating that Chl proteins are not responsible for citric acid export. Furthermore, the ChlH overexpression strain displayed an accumulation of 2-oxoglutaric and fumaric acids in the culture supernatant, while the ChlK overexpression strain exhibited the accumulation of 2-oxoglutaric, malic and succinic acids. Notably, the ChlH and ChlK overexpression led to a substantial increase in the production of 2-oxoglutaric acid, reaching approximately 25mM and 50mM, respectively. Furthermore, ChlH and ChlK overexpression also significantly increased the secretory production of dicarboxylic acids, including 2-oxoglutaric acid, in the yellow koji fungus, Aspergillus oryzae. Our study demonstrates that overexpression of DHA1 family gene results in enhanced secretion of organic acids in koji fungi of the genus Aspergillus.

Sustainability Assessment of Highly Fluorescent Carbon Dots Derived from Eucalyptus Leaves

Biomass-derived carbon dots (CDs) are gaining much interest in recent times, as they provide a sustainable option with abundant availability, a low cost and tunable luminescence. Herein, we report a simple green synthesis method to produce highly fluorescent CDs from Eucalyptus globulus leaves using the one-pot hydrothermal approach. The fabricated CDs exhibit strong blue fluorescence with an excitation and emission maxima of 320 nm and 445 nm, respectively. The highest quantum yield (QY) obtained was 60.7%. With the reported optical properties and biocompatibility, CDs can be looked at as a promising candidate for potential biosensing applications. Moreover, we employed a life cycle assessment (LCA) cradle-to-gate approach to study the environmental impacts of the synthesis strategy used for the fabrication of CDs. The results point out that citric acid is the main hotspot in CD synthesis, regarding environmental impacts in most categories. This justifies the introduction of biomass, which reduces the amount of citric acid, thus leading to a more sustainable synthesis strategy for fabricating CDs.

Tailoring quantum dots through citric acid modulation of CoFe2O4 ferrite

In the pursuit of advancing materials science, the focus has been on the development of Quantum dot CoFe2O4, a fascinating realm where the minuscule holds the key to great potential. By utilizing the cost-effective sol-gel method and adjusting the concentration of citric acid, we embarked on a journey to explore the intricacies of this magnetic material. XRD measurements determined the phase and structural characteristics of the synthesized cobalt ferrite. The Rietveld refinement clearly shows the single-phase cubic structure described by Fd-3m space group. The broad peak indicates the Quantum dots and nano sized particles depending on the FWHM, also the Debye Scherrer formula has been used to calculate the crystallite size of the prepared sample. It was found that the average crystallite size of different samples of CoFe2O4 lied in the range of 4.8–38.4 nm (Quantum dot to Nanometer range). The FWHM (full width at half maximum) broadening varied according to the citric acid, as the amount of citric acid increased, the FWHM decreased, which has been clearly seen in the XRD pattern. The required calculations were performed to ascertain micro-strain in the sample with the help of the W–H plot. For the surface morphological study, Field Emission Scanning Electron Microscopy (FE-SEM) was performed for all samples, which suggested that all samples were well prepared and were in spherical shape. The EDAX confirmed the elemental composition present in the prepared samples of CoFe2O4. The Raman spectra supports our XRD data also deconvoluted Raman spectras suggest about the vibrational modes present in the sample and the three strong first-order Raman modes Eg, T2g, and A1g, were observed. As we delved deeper into vibrational harmonies, Raman spectroscopy unveiled a symphony of modes. The presence of different chemical bonds has been confirmed by the Fourier Transform Infrared Rays (FTIR) Spectroscopy.

Modeling and investigation of swelling kinetics of sodium carboxymethyl cellulose/starch/citric acid superabsorbent polymer

Crosslinked hydrophilic polymers with high water absorption rates are known as superabsorbent polymers (SAPs). Most commercial superabsorbent polymers are made with acrylic acid, which is difficult to biodegrade. So, in this investigation, carboxymethyl cellulose (CMC) was utilized as a significant component in the synthesis of polysaccharide-based SAPs. Citric acid (CA) and starch were chosen as crosslinking agents because they are more eco-friendly, non-toxic, and biodegradable than traditional crosslinking agents. FTIR analysis revealed that the superabsorbent polymer product contains a crosslinked structure of CMC and starch with side chains that carry carboxylate functional groups. Superabsorbent weight loss and grafting data were satisfactorily studied using the TGA approach. Under optimum circumstances, the SAP2 water absorbency capacity in distilled water was 287.37 g.g−1 and SAP1 absorbency capacity in a solution containing 0.9 wt% NaCl was 52.18 g.g−1. Moreover, Schott's pseudo-second-order model was used to determine the kinetic swelling of the superabsorbent. The initial swelling rate of SAPs can be calculated using the Q∞ data acquired in the following order: SAP2 > SAP1 > SAP3 > SAP4 in distilled water and SAP1 > SAP2 > SAP3 > SAP4 in 0.9 wt% NaCl solution, respectively. The findings suggested that a small amount of citric acid introduced into the SAPs matrix could enhance the swelling rate of SAPs. The results of the cytotoxicity tests show that the extraction liquid of composite hydrogel fibers is less cytotoxic than the positive control. As well, SAP underwent in silico docking investigations on the DNA Gyrase enzyme. As the ligand is a monomer of SAP, it was a long chain of carbohydrate molecules with alcoholic groups, esters groups, and keto groups forms a strong binding interaction with DNA gyrase.

Biological Detoxification of the Inhibitors in Corncob Acid Hydrolysate Using Aspergillus niger

The biological detoxification of lignocellulose hydrolysate is an effective method through which to enhance microbial fermentation efficiency. In this study, an inhibitor-tolerant strain of A. niger (Aspergillus niger) was used for the biological detoxification of corncob hydrolysate. The results showed that A. niger M13 can tolerate a concentration of at least 7.50 ± 0.19 g/L of acetic acid, 1.81 ± 0.13 g/L of furfural, and 1.02 ± 0.10 g/L of HMF (5-Hydroxymethylfurfural). The spores had a higher detoxification efficiency than the mycelial pellets with a detoxification rate of 0.1566 g/L/h, 0.1125 g/L/h, and 0.015 g/L/h for acetic acid, furfural, and HMF, respectively. The cell preferentially consumed furfural, then HMF, before simultaneously degrading acetic acid and glucose. A. niger M13 spores could accumulate small amounts of citric acid directly from undetoxified hydrolysate at a concentration of about 6 g/L. Therefore, A. niger M13 can serve as an excellent biological detoxification strain and a potential citric acid fermenting strain when using undetoxified lignocellulosic hydrolysates.

Investigation on anodized 5052 aluminum alloy and its corrosion resistance in simulated acid rain

5052 Al alloy commonly used for construction structures was anodized from the mixed acid electrolyte of citric acid and sulfuric acid to further improve the durability of Al alloy construction components. Different anodized aluminum alloys were prepared by changing the concentration of citric acid in the electrolyte. The surface morphology, structure, thickness and corrosion resistance of the anodized aluminum alloys were characterized and analyzed. The results show that adding appropriate amount of citric acid has a certain corrosion inhibition effect, which reduces the corrosion dissolution degree of the anodized aluminum alloy. At the same time, adding appropriate amount of citric acid in the electrolyte is beneficial to increase the thickness of anodized aluminum alloy, resulting in the enhancement of corrosion resistance in simulated acid rain. When the concentration of citric acid in the electrolyte is 70 g/L, the anodized aluminum alloy is uniform with higher thickness and better corrosion resistance in simulated acid rain.

Synthesis and Characterization of Agarose Hydrogels for Release of Diclofenac Sodium.

Hydrogels are attractive biomaterials for the controlled release of various pharmaceuticals, due to their ability to embed biologically active moieties in a 3D polymer network. Among them, agarose-based hydrogels are an interesting, but still not fully explored, group of potential platforms for controlled drug release. In this work, agarose hydrogels with various contents of citric acid were prepared, and their mechanical and physicochemical properties were investigated using various instrumental techniques, such as rheological measurements, attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR). Releasing tests for diclofenac sodium (DICL) were run in various environments; water, PBS, and 0.01 M NaOH; which remarkably affected the profile of the controlled release of this model drug. In addition to affecting the mechanical properties, the amount of citric acid incorporated within a hydrogel network during synthesis was also of great importance to the rate of DICL release. Therefore, due to their high biocompatibility, agarose hydrogels can be regarded as safe and potential platforms for controlled drug release in biomedical applications.

Production of Liquid Biofuel Precursors: Optimization and Regulation of Lipase Fermentation and Its Application in Plant Oil Hydrolysis Process

In the liquid biofuel production process, free fatty acids are important precursors for biodiesel and bio-aviation fuel. Enzymatic hydrolysis to produce free fatty acids has attracted more and more attention. However, enzymatic hydrolysis requires ensuring efficient expression of lipase and high product yield. In the shaking flask, the optimal addition amount of citric acid was 3 g/L, and the composition of composite amino acids was: histidine 0.1 mol/L, aspartic acid 0.03 mol/L and lysine 0.03 mol/L. On the basis of the shaking flask optimization, a 5 L fermentation tank was scaled up to obtain 25,000 U/mL of lipase after multiple batches of stable fermentation. This was the first time to cultivate Y. lipolytica using composite amino acid medium to produce high enzyme-activity lipase, demonstrating the industrial value of this lipase fermentation process. Finally, soybean oil was hydrolyzed to produce free fatty acids on a self-made static reactor. The optimized reaction conditions were: material flow rate 2813 mL/min, reaction temperature 45 °C, water content 25 wt% and lipase consumption 3 wt%. The yield of free fatty acids was 80.63% after 12 h under optimal reaction conditions in the self-made static reactor, 11.95% higher than that in the stirred reactor, which showed its industrial potential in the production of free fatty acids.

From 0D to 3D: Controllable synthesis of ammonium vanadate materials for Zn2+ storage with superior rate performance and cycling stability

Vanadium-based materials are one of the most promising cathodes for aqueous zinc ion batteries owing to their adjustable layered structure and high specific capacity. However, the sluggish Zn2+ diffusion kinetics and inferior structural stability still hinder their further development. Here, selective control of the structure of ammonium vanadate (NVO) materials is successfully achieved by a simple hydrothermal method, and the relationship between structure and performance is clarified. It was found that the amount of citric acid in the precursor solution is a vital factor for this morphology evolution. Density functional theory calculations show that the oxygen vacancies could modulate the electron structure of NVO and effectively weaken the electrostatic interaction between Zn2+ and the NVO lattice. Benefitting from the isotropic structure with abundant oxygen vacancies, the amorphous NVO nanodots exhibit superior reaction kinetics. The specific energy of 148.5 Wh kg−1 was achieved at a power density of 3300 W kg−1, along with a high capacity retention of 81% even after 5000 cycles at 5 A g−1. This work not only provides a new strategy for the controllable synthesis of vanadium-based materials but also reveals the great application potential of amorphous materials in metal-ion batteries.