Aluminum Nitrate Research Articles

Exploration of properties (crystallographic, morphological, optical) of nano cobalt aluminate synthesized by facile sol–gel method: Effects of sintering temperature

The present work reports on the facile sol–gel synthesis of CoAl2O4 nanoparticles using cobalt nitrate and aluminum nitrate as the metal salts and citric acid and glycerol as chelating agents. The consequence of sintering temperature on the structure, particle size, morphology, composition, zeta potential, color, and reflectance spectra at neutral pH condition were explored with various instrumental techniques. The CoAl2O4 nanoparticles were characterized with Powder X-ray diffraction (PXRD), Fourier-transform infrared spectroscopy (FT-IR), Field emission scanning electron microscopy (FESEM), Energy dispersive spectroscopy (EDS), Nanoparticle size analyzer, Ultraviolet–Visible Diffuse Reflectance Spectroscopy (UV–Vis-DRS) and CIE-Lab colorimetric method. From the data of PXRD, the crystallite size and peak profile analysis were investigated by four different models. It was found that the average crystallite size varied in the range of 28.01–320.97 nm and single-phase cubic CoAl2O4 was formed without any impurity. The average particle size of CoAl2O4 nanoparticles was discerned from the FESEM images using ImageJ software and from a nanoparticle size analyzer. The average particle sizes were increased with the increasing sintering temperature. The values of zeta potential found in all of the samples represented high dispersion stability. From the colorimetry of CoAl2O4 nanoparticles, the CIE-La*b* output illustrated high purity and brightness and the spectra.

The effect of the preparation method of asphalt waste foam ceramic loaded Pd/Ce-P-Al2O3 coatings on their properties

Asphalt waste-based foam ceramics were prepared by organic foam impregnation, followed by ultrasound-assisted impregnation and calcination to deposit 3-5 wt.% Pd/Ce-P-Al2O3 active coatings. The results show that γ-Al2O3 as an aluminum source provides a higher specific surface area and facilitates the dispersion of the catalytic components, so that low-temperature conversion of CO can be achieved, but the coating uniformity, stability, and the ability to modify the defects on ceramic surfaces are lower than those of the aluminum nitrate calcination products. Aluminum dihydrogen phosphate as a P source could rapidly convert 60% of CO, but the performance decreased at a later stage, while phosphoric acid as a P source could achieve the complete conversion of CO at a lower temperature. The mechanical properties of the samples with the addition of aluminum dihydrogen phosphate and aluminum nitrate baked products were better, which was 0.6 MPa higher than the uncoated foam ceramics.

Research on structural strengthening technology for regenerative denitration catalysts.

The cost of replacing failed selective catalytic reduction (SCR) catalysts and their disposal as hazardous solid waste is high. If failed catalysts are recovered and regenerated into new SCR denitration catalysts, the cost of flue gas denitration can be effectively reduced. However, regenerated SCR catalysts have relatively low structural strength and activity and cannot yet form an effective replacement. In this study, aluminum dihydrogen phosphate, aluminum nitrate, and aluminum sulfate were used as structural strengthening agents in the regeneration of SCR catalysts, and over-impregnation, drumming-assisted impregnation, and ultrasonic-assisted preparation techniques were compared. The corresponding regenerated SCR catalysts were then prepared and analyzed for compressive strength, wear strength, H2-TPR, NH3-TPD, and in situ IR. Factors influencing the structural strength, physical properties, and catalytic activity of the regenerated catalysts were investigated. The best results were obtained as follows: compressive strength of 4.57 MPa, wear rate of 0.088% kg-1, and denitration of 58% after 10 min of drumming-assisted impregnation in an aluminum sulfate solution with a concentration of 16%. Based on this, a synergistic method for catalyst activity and structural strengthening was explored to support the design of better SCR catalysts for regeneration.

Portable paper-based probe for on-site ratiometric fluorescence determination of total flavonol glycosides in plant extract using smartphone imaging.

A smartphone-assisted, paper-based ratio fluorescence probe is presented for the rapid, low-cost and on-site quantification of total flavonol glycosides in Ginkgo biloba extracts (GBE). The Al3+/Eu-MOF/paper-based probe utilizes lanthanide metal-organic framework (Ln-MOF) nanoparticles immobilized on Whatman filter paper along with Al3+ for detecting flavonols, which are the hydrolyzed products of flavonol glycosides. The color change of the paper-based fluorescence image from red to orange depends on the concentration of the target analyte in the sample solution. The smartphone equipped with a red, green, blue (RGB) color detector measured the fluorescence signal intensity on the paper substrate after adding flavonol. The analytical variables affecting the performance of the probe, including the addition sequence of the aluminum nitrate solution, its concentration, that of the Ln-MOF solution, the drying time of the paper probe, the reaction time and the sensitivity parameters of the mobile phone camera (ISO), were optimized. Under optimal conditions, the Al3+/Eu-MOF/paper-based probe has good linear response in the concentration range 7 ~ 80µg mL- 1 and a lower detection limit of 2.07µg mL- 1. The results obtained with the paper-based ratio fluorescence probe and smartphone combination were validated by comparing them with high-performance liquid chromatography (HPLC) measurements. This study provides a potential strategy for fabricating Al3+/Eu-MOF/paper-based probe used for total flavonol glycosides determination.

Study On the Uniformity Aluminum Nitrate Thin Film On 2-Inch Silicon Substrate Prepared by RF Magnetron Sputtering

Aluminum nitrate (AlN) has attracted the researcher's interest due to its unique properties in the semiconductor material and other high-performance devices. This results in numerous techniques to investigate the uniformity of AlN thin film. The deposition in this study is carried out on an AlN on a 2-inch silicon substrate using a magnetron sputtering technique. The RF magnetron sputtering can also produce better film quality and deposit a wide variety of insulators, metals, alloys and composites. In this study, the AlN film was deposited using the RF magnetron sputtering by using three different parameters for the growth of the AlN on the 2-inch Si substrate for uniformity analysis. The uniformity of AlN thin film includes analyses of the structural, thickness, topology and surface morphology by using the characterization of X-ray diffraction (XRD), atomic force microscopy (AFM), surface profiler and field emission scanning electron microscopy (FE-SEM). Based on the result from three parameters that have been done, parameter one shows the best results. For the crystalline structure results, the peak (100) AlN indicates the highly textured phases similar to a single crystal, and the cross-section result in FE-SEM shows the homogenous thickness.

Enhanced Characterisation Studies and Synthesis of Undoped and Copper Doped-Organic Nonlinear Optical Single Crystal: L-Alanine Aluminium Nitrate

Single crystals of untreated and copper (Cu2+) metal ion-doped L-alanine aluminium nitrate (LAAN), a room-temperature slow evaporation organic nonlinear optical material. Single crystals were studied for structural, spectral, optical, hardness, secondorder non-linear optical, electrical [(alternating current (AC) and direct current (DC)], and photoconductivity properties as they grew. Crystallinity, monoclinic structure with space collection P21, and lattice specifications were deliberate using single crystal X-ray diffraction investigation. The existence of functional clusters is revealed by the spectral properties, and the means of vibration of various molecular clusters existing in LAAN were evaluated using Fourier transform infrared (FTIR). The low cut-off wavelength and transmittance properties were determined using optical analysis. The band gap energy of LAAN and Cu-doped LAAN crystals was estimated to be 3.40 eV and 2.70 eV, respectively, using the Tauc plot. It was revealed that pure crystals had a lower dielectric constant than crystals that had been doped with copper. After doping with rising temperatures, AC conductivity started to rise. With the use of the Kurtz and Perry approach, the effectiveness of the grown crystal’s second harmonic generation was computed, Cu-doped LAAN was discovered to be 3.3 times more prominent than potassium dihydrogen phosphate (KDP) and 2.2 times more prominent than pure LAAN crystals. The nonlinear optical characteristics of LAAN crystals have therefore been improved by copper doping. It is most suited for use in electro-optic applications like laser technology, telecommunications and optical signal processing because of its negative photoconductivity.

An efficient wastewater treatment through reduction of organic dyes using Ag nanoparticles supported on cellulose gum beads

This work reports silver nanoparticles (AgNPs) supported on biopolymer carboxymethyl cellulose beads (Ag-CMC) serves as an efficient catalyst in the reduction process of p-nitrophenol (p-NP) and methyl orange (MO). For Ag-CMC synthesis, first CMC beads were prepared by crosslinking the CMC solution in aluminium nitrate solution and then the CMC beads were introduced into AgNO3 solution to adsorb Ag ions. Field emission scanning electron microscopy (FE-SEM) analysis suggests the uniform distribution of Ag nanoparticles on the CMC beads. The X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) analysis revealed the metallic and fcc planes of AgNPs, respectively, in the Ag-CMC catalyst. The Ag-CMC catalyst exhibits remarkable reduction activity for the p-NP and MO dyes with the highest rate constant (kapp) of a chemical reaction is 0.519 and 0.697 min−1, respectively. Comparative reduction studies of Ag-CMC with CMC, Fe-CMC and Co-CMC disclosed that Ag-CMC containing AgNPs is an important factore in reducing the organic pollutants like p-NP and MO dyes. During the recyclability tests, the Ag-CMC also maintained high reduction activity, which suggests that CMC protects the AgNPs from leaching during dye reduction reactions.

Epoxide-Mediated Synthesis of Two-Component Al2O3–TiO2 Aerogels and Their UV-Protective Characteristics

A new method was proposed to synthesize aerogels based on Al2O3–TiO2 by the hydrolysis of mixed solutions of titanium tetrachloride and aluminum nitrate in the presence of propylene oxide, followed by supercritical drying of the obtained gels. The aerogels are characterized by a high specific surface area (140–500 m2/g) and a high specific porosity (1.7–2.7 cm3/g). Heat treatment of the Al2O3–TiO2 aerogels at temperatures up to 600°C does not lead to crystallization of titanium dioxide, whereas the formation of crystalline anatase in aerogels based on individual TiO2 is observed already at a temperature of 450°C. Using the standardized ISO 24443-2016 method, the SPF value of the obtained materials was determined, which turned out to be comparable to the characteristics of a commercial inorganic UV filter based on TiO2 (Kronos 1171). At the same time, the photocatalytic activity of the Al2O3–TiO2 aerogels turned out to be more than 120 times lower than the similar characteristics of the commercial UV filter based on titanium dioxide. The results obtained demonstrated that the Al2O3–TiO2 aerogels are promising as components of sunscreens.

Performance of Cu/ZnO/Al2O3 Catalysts Prepared by Sol–Gel Methods on Methanol Steam Reforming

Cu/ZnO/Al2O3 catalysts were prepared for online methanol steam reforming (MSR) using a conventional sol–gel method in this study. The optimal preparation conditions, including the calcination temperature, Cu loading, molar ratio of citric acid to metal ions (CA/M), and pH, were investigated. CZA50 exhibited the highest MSR activity among all catalysts. It was prepared at a calcination temperature of 350 °C; Cu, Zn, and Al molar fractions of 50%, 30%, and 20%; CA/M of 1.5; and without adjusting pH. Furthermore, a modified sol–gel method was proposed to enhance the mechanical strength of Cu/ZnO/Al2O3 catalysts by using γ-Al2O3 powders as catalyst precursors instead of aluminum nitrates. In this modified method, part of Cu2+ and Zn2+ ions were impregnated firstly on γ-Al2O3 powders, and then the remaining metal ions formed sol–gel with citric acid. MCZA-0.25 catalysts prepared by this modified method showed superior catalytic activity at an Al/(Cu+Zn) ratio of 0.25. The methanol conversion rates of CZA50, MCZA-025, and CZA-Commercial were 82.9%, 79.4%, and 74.7% at the temperature of 200 °C and methanol liquid phase space velocity (LHSV) of 1.0/h, respectively. The average crushing strength of CZA50, MCZA-0.25, and CZA-Commercial were measured as 28 N/cm, 37 N/cm, and 32 N/cm, respectively.

The effect of different anions on the crystallization course of α‐Al2O3 powder in hydrothermal method

Abstractα‐Al2O3 powder with excellent sintering properties plays an irreplaceable role in advanced ceramics. However, the preparation of α‐Al2O3 at low temperature still remains a grand challenge. Herein, aluminum sulfate, aluminum nitrate, and aluminum chloride are used as raw materials for α‐Al2O3 synthesis. In general, the Al3+ will be hydrolyzed to form AlOOH during the hydrothermal process. But SO42− reacted with Al3+ and OH− to form Al4(OH)10SO4 during the hydrothermal process. During the calcining process, the transition temperatures from AlOOH to α‐Al2O3 were 1100°C, which can be summarized as follows: AlOOH → γ‐Al2O3 → θ‐Al2O3 → α‐Al2O3. Meanwhile, Al4(OH)10SO4 converted into pure α‐Al2O3 at only 1050°C, due to the direct conversion from γ‐Al2O3 to α‐Al2O3. This spherical α‐Al2O3 was made up by completely uniformed small particles of about 10–20 nm. Finally, an Al2O3 ceramic with 98.07% of theoretical density and .01% water absorption rate was obtained at a temperature of 1600°C. This work offers an intriguing solution toward the development of Al2O3‐based advanced ceramics.

On the structural and optical characterization of zinc aluminate nanoparticles synthesized via green microwave route

Zinc aluminate, a widely employed wide bandgap semiconductor, boasts exceptional mechanical and thermal properties, coupled with a high quantum yield. Its versatile applications include photocatalytic pollutant degradation, utilization in displays, and contributions to the medicinal field. However, challenges arise during synthesis processes, where high-temperature annealing reduces nanoparticle surface area, and cation contamination from precursors impacts material purity. In response to these challenges, green synthesis methods incorporating plant extracts as reductants have emerged to yield higher-quality phosphors. In this study, the focus is on microwave synthesis of Zinc Aluminate using Zinc Nitrate and Aluminum Nitrate in varying ratios as precursors. Comprehensive structural and optical characterizations, including X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), Diffuse Reflectance Spectroscopy (DRS), and Photoluminescence Spectroscopy (PL), have been conducted to assess the influence of precursor molar ratios on the spinel growth and optimization of the synthesis process.

Study on preparation of aluminum fluoride from cryolite

As China's aluminum electrolysis industry expanded its production capacity, it produced a large amount of bath materials– cryolite based molten salt, which is not utilized fast enough and piled up in aluminum factories. It is of great significance to find a proper way to process the accumulated bath materials. Through the method introduced in this paper, aluminum fluoride can be produced from cryolite-based electrolyte and fed back into the aluminum electrolysis cell as a necessary additive. This method includes four steps: Calcination of crystalline aluminum nitrate with cryolite. Cryolite and crystalline aluminum nitrate are mixed and preheated. The main chemical reaction that occurs in this step will produce sodium nitrate (NaNO3), β-aluminum fluoride (β-AlF3), chiolite (Na5Al3F14) and the aluminum hydroxyfluoride hydrate (AHF). After calcination, the products are washed with water to separate soluble NaNO3 from the other products. The insoluble products obtained after washing are calcined with ammonium bifluoride to convert AHF into AlF3. The mixture obtained after preheating is then washed with an aqueous solution of aluminum salt (such as Al(NO3)3) to remove Na5Al3F14. Aluminum fluoride of high purity is obtained in the end. Calcination step is the most important among the four steps. The effects of calcination temperature (85 – 135 ℃) and molar ratio of crystalline aluminum nitrate to cryolite (0.5 – 2) on the conversion rate of cryolite were studied. The experimental results show that the highest conversion rate of cryolite can reach 97.03%. Through SEM, EDS, ICP and other analysis methods, it was found the final products contained more than 98.8 wt% aluminum fluoride and less than 0.4 wt% sodium, and the average particle size of aluminum fluoride is approximately 15 – 20 µm.

Metal oxide and nitrate-modified calcium gluconate-based sorbent with high stability for integrated carbon capture and utilization process

In this study, metal oxides (MgO, CeO2, and Al2O3) and metal nitrates (Mn(NO3)2, Al(NO3)3, Mg(NO3)2, and Fe(NO3)3) were used to modify calcium gluconate-based sorbents for the integrated CO2 capture and utilization (ICCU) process. We employed conventional thermogravimetric analysis (TGA) and microfluidized bed thermogravimetric analysis coupled with mass spectrometry (MFB-TGA-MS) to explore the cyclic CO2 capture behavior, physical and chemical properties, and morphology in detail. Our findings reveal that calcium gluconate modified with aluminum nitrate (CG-Al-N) exhibited superior CO2 capture capacity (9.81 mmol∙g−1 over 20 cycles), along with a high surface area (35.67 m2∙g−1) and pore volume (0.16 cm3∙g−1). In comparison, pure calcium gluconate displayed a capacity of 7.09 mmol∙g−1, a surface area of 27.66 m2∙g−1, and a pore volume of 0.06 cm3∙g−1, while commercial calcium oxide demonstrated 1.96 mmol∙g−1, 4.62 m2∙g−1, and 0.01 cm3∙g−1, respectively. Notably, after 100 cycles, CG-Al-N retained a CO2 capture capacity of 11.75 mmol∙g−1, achieving 66% of the capacity of the pure CaO sorbent. This observation strongly suggests that CG-Al-N has excellent anti-sintering properties. Furthermore, data was acquired under fluidized and isothermal conditions by utilizing MFB-TGA-MS. CG-Al-N consistently exhibited an average CO2 capture capacity (9.57 mmol∙g−1), CO yield (5.00 mmol∙g−1), and CO selectivity (∼100%) over 20 ICCU cycles, with the dominant route being the reverse water–gas shift (RWGS) reaction, highlighting the self-catalytic activity of gluconate-based sorbents. Morphological evolution also revealed finer pores and a skeleton structure of cycled CG-Al-N, which affirms the unobstructed gas entry and ensures a continuous gas–solid reaction.

Optimizing the quality of bioactive glass-polymer coatings through analysis of the effect of dispersing agents on zeta potential and suspension conductivity

Bioactive glass-polymer (BG-Pol) composite coatings have garnered attention in biomedical applications due to their potential to improve implant performance. This research examines the effects of aluminium nitrate nonahydrate, citric acid, and triethylamine as dispersing agents on the zeta potential and suspension conductivity of BG-Pol suspensions in a 100 % isopropanol suspension. It examines the impact on solutions’ electrostatic and conductive behaviour during electrophoretic deposition to enhance coating deposition. The suspensions having a zeta potential above the stability regime (e.g., above 40 mV for polyethylene glycol suspensions) can give a homogeneous coating without dispersants, but below the stability regime, dispersants enable a more uniform coating. The effective deposition was facilitated by a higher suspension conductivity, which exceeded 0.003 mS/cm.

Heat insulating properties of mullite hollow fibers prepared by using the template of reed fibers

Mullite fibers have a wide range of applications in thermal insulation. Currently, most mullite fibers produced have solid structures, limiting their heat-insulating properties. In this study, we present a method for producing mullite fibers with hollow structures using reed fibers as templates. The reed fibers were immersed in a solution containing aluminum nitrate and ethyl orthosilicate, followed by high-temperature sintering to obtain mullite hollow fibers with excellent heat-insulating properties. The microstructures, phases, pore size distributions, and thermal conductivities of the resulting fibers were analyzed. The results demonstrated that mullite hollow fibers exhibited lower thermal conductivities compared to solid mullite fibers, mainly due to the more effective prevention of air convection facilitated by the hollow structures. The introduction of hollow structures into mullite fibers using reed fibers as templates offers a promising approach for improving thermal insulation performance. This finding highlights the enhanced heat-insulating capabilities of mullite hollow fibers.

Synthesis of N-monosubstituted ureas in a mixture of choline chloride and aluminium nitrate as a simple, efficient, and selective process

Synthesis of N-monosubstituted ureas in a mixture of choline chloride and aluminium nitrate as a simple, efficient, and selective process

Preparation, microstructure and corrosion resistance of Al2O3 coatings by cathodic plasma electrolytic deposition on sintered NdFeB permanent magnet

The Al2O3 ceramic coatings were prepared on the sintered NdFeB magnets by cathodic plasma electrolytic deposition (CPED) method in aluminum nitrate alcohol solution. The surface and cross-sectional morphologies, element and phase composition, corrosion resistance and magnetic properties of the coatings were analyzed by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), thermal shock, hydrothermal weight loss, electrochemical corrosion and physical property measurement system (PPMS), respectively. The results show that the coatings mainly consist of γ-Al2O3 and α-Al2O3 phases, and the volume of α-Al2O3 increases with increasing the voltages. The surface of the coatings shows a typical coral reef structure, and the thickness of the coatings increases from 29 µm to 53 µm with increasing the voltages. The Al2O3 coatings have excellent thermal shock resistance as well as the excellent corrosion resistance in hydrothermal conditions. The corrosion resistance of the coatings enhances with increasing the voltages, reaching the strongest at 470 V, and then decreases. This study provides a new method for forming ceramic coatings on the surface of sintered NdFeB magnets to improve its corrosion resistance.

Toward a tunable fabrication of multifunctional iron-aluminum spinels via solution combustion synthesis: The effects of fuel, heating mode, and Fe:Al precursor ratio

The solid solutions of iron and aluminum spinels (hercynite, maghemite, magnetite, and γ-alumina) are promising materials for emerging technologies such as solar thermochemical fuel production and clean dehydrogenation of fossil fuels. Solution combustion synthesis (SCS) is an attractive technique for the fabrication of these materials as it has been used for synthesis of many nanoscale oxides. However, the design space of SCS is large with many synthesis parameters affecting the properties of the combustion products. To optimize the SCS of these materials, it is important to determine which parameters yield the best properties. In the present work, FeAlOx nanocomposites were obtained by SCS using iron nitrate and aluminum nitrate as precursors and oxidizers. Two fuels (citric acid and glycine), three Fe:Al molar ratios (1:2, 1:1, and 2:1) in the precursors, and three heating modes (hotplate, muffle furnace, and microwave oven) were compared. The products were characterized by X-ray diffraction analysis, scanning electron microscopy, Brunauer-Emmett-Teller surface area analysis, and laser diffraction particle size analysis. The fuel used had the largest impact on the combustion behavior and hence the material properties. The high combustion temperature of glycine allowed for the formation of an FeAl2O4/Fe3O4 solid solution, while the lower-temperature combustion of citric acid yielded Al-substituted γ-Fe2O3 with high amorphous content. With citric acid, the specific surface area as high as 200 m2/g was achieved. The effect of Fe:Al precursor ratio was clearly seen in variations of the lattice parameter, which demonstrated the ability to tune the phase composition. The heating mode had minor effects on material properties, but some differences were observed. All products obtained by SCS in a microwave oven had low specific surface areas compared to those obtained with a hotplate and a muffle furnace.

Effect of Calcination Temperature on Prepared Γ-Al2O3 as Support Catalyst

The effect of calcination temperature on the surface properties of gamma alumina was investigated in this study, which is used as a support for multiple metal-loaded catalysts. The Sol-gel technique was used to create -Al2O3 support from aluminum nitrate as a precursor at various calcination temperatures (500, 550, 600, and 650°C). Then, for each sample, characterization tests such as X-Ray fluorescence (XRF), X-Ray diffraction (XRD), Thermal gravimetric analysis (TGA), and surface area (BET) are performed to determine the optimal calcination temperature to produce highly active composite catalyst support. It has been discovered that samples calcined at 600 and 650°C have very similar properties in terms of mechanical strength, thermal stability, crystallinity, high purity, and surface properties or morphology. However, the surface area and pore volume of 600°C are thought to be superior to those of 650°C.

Synthesis of ZnO-Al:TiO<sub>2 </sub>Materials and their Characterization as Photocatalyst Compounds

Photocatalyst activity relates to the active surface area between pollutants and catalyst compounds. The insertion of Al atoms as a substantial defect in ZnO structures can reduce the particle size thus the active surface area increases. Another way to raise the photocatalytic activity of ZnO is by combination with other oxide materials such as TiO2 (Titanium dioxide). In this study, the ZnO-Al:TiO2 powder was successfully prepared via the sol-gel method using zinc acetate dihydrate as a precursor, 0.5wt% of aluminum nitrate nonahydrate as a dopant precursor, and TiO2 anatase. In order to understand the role of the combination of these two metal oxides, the concentration ratio of ZnO-Al and TiO2 was varied by 1:1 (ZAT) and 4:1 (ZA4T) under low (150°C) and high (450°C) temperature calcination. Photocatalytic testing was carried out using a 3.2 ppm methylene blue (MB) solution under UV-A lamp irradiation for 120 minutes. The high calcination temperature facilitates the growth of ZnO-Al. Besides that, the different ratio concentrations and calcination temperatures produce different defect states in each sample. The most optimum results in the photocatalytic activity performed by ZnO-Al:TiO2 150°C (ZAT 15) with degradation rate constant (k) of 0.033/min and efficiency of 97% for MB removal. The unexpected zinc vacancies defect is estimated produce at the samples in high-temperature calcination. This defect type can accelerate electron-hole pair recombination. In Addition, samples with high-temperature calcination were considered to have lower hydroxyl/oxygen bonds on the surface thus affecting the photocatalytic performance.