Optimum Annealing Temperature Research Articles

Wheatstone Bridge MEMS Hydrogen Sensor with ppb-Level Detection Limit Based on the Palladium-Gold Alloy.

On some occasions, such as new energy clinics, monitoring the trace hydrogen at the ppb level is necessary. The traditional resistive hydrogen sensors based on the Pd alloys are very difficult to realize such an extremely low detection limit. To achieve a detection limit at the ppb level and also ensure good stability, a MEMS hydrogen sensor was designed in a suspended Wheatstone bridge structure, with all four resistive arms defined on a sputtered Pd-Au alloy thin film. For the Wheatstone bridge sensor, absolute response (Ra) and relative response (Rs) are defined to describe the sensitivity of the sensor, and the effect of annealing temperature on baseline drift is investigated using the baseline zero drift parameter (DBZD). By testing the sensors across a hydrogen concentration range of 20 ppb to 3 v/v%, the optimal annealing temperature (250 °C) and operating temperature (60 °C) were identified. Under these conditions, the sensor exhibited a detection limit as low as 20 ppb with a power consumption of only 4.6 mW. At the same time, the response and recovery times of the sensor were 6 and 19 s, respectively, toward 3 v/v% hydrogen. After testing over a 100-day period, Ra fluctuated only 0.0026%, indicating that the hydrogen sensor had good long-term stability for low-concentration detection. More results also showed that the sensor has good repeatability, selectivity, and humidity resistance. With the wide measurement range (20 ppb to 3 v/v%), the sensor has the potential to meet hydrogen detection requirements in multiple scenarios.

Photoelectrochemical and Structural Insights of Electrodeposited CeO2 Photoanodes

Cerium dioxide (CeO2) is a promising material for photoelectrochemical applications, requiring a thorough understanding of the interplay between its properties and structure for optimal performance. This study investigated the photoelectrochemical performance of CeO2 photoanodes immobilized by electrodeposition on glass substrates, focusing on the correlation between the annealing temperature and structural, optical, and electrical changes. CeO2 coatings were obtained via chronoamperometry in an aqueous solution of 25 mM CeCl3 and 50 mM NaNO₃. The photoelectrochemical characterization included the evaluation of photoactivity, current density, stability, and recombination using linear sweep voltammetry (LSV) and chronoamperometry (CA). Charge transfer resistance, flat-band potential, and capacitance were assessed through impedance spectroscopy. The optimal annealing temperature for this material was found to be 600 °C as it resulted in the lowest charge transfer resistance and increased photocurrent, which was attributed to enhanced crystallinity and variations in the Ce3+/Ce4+ ratio.

Effect of annealing on ion-beam-sputtered hafnium oxide thin films properties

HfO2 films are high laser damage-threshold and low-absorption thin-films that can be utilized for a broad range of optoelectronic and optical applications. In this study, HfO2 thin films were prepared via dual ion beam sputtering followed by annealing in the atmosphere at temperatures ranging from 200 to 700 °C. The optical properties, microstructure, film stress, and absorption loss of the HfO2 films at various annealing temperatures were then systematically characterized. The results revealed that the properties of the films were improved after annealing at temperatures below 500 °C. Specifically, at an optimal annealing temperature of 400 °C, the residual stress of the films was minimized close to zero and the absorption loss was as low as 1 ppm. However, at annealing temperatures reaching 600 °C, the films began to crystallize, leading to the deterioration of their optical properties. Optimizing the process parameters for HfO2 thin film deposition is crucial for developing the next generation of high-performance laser optics.

Enhanced Pyroelectricity Over Extended Thermal Range in Flexible Polymer Thin Films

AbstractPolymer‐based pyroelectric thin films are crucial functional materials at the core of flexible and lightweight electronic devices, such as wearable monitoring sensors, energy harvesters, and infrared detectors. Nevertheless, the pyroelectric properties of the polymer films, such as poly(vinylidene fluoride‐trifluoroethylene) (P(VDF‐TrFE)), vanish when the surrounding temperature exceeds the ferroelectric‐to‐paraelectric transition temperature, and thus limits their pyroelectric performance to a low‐temperature range. Herein, to mitigate this issue by employing a new class of P(VDF‐TrFE) copolymer which has a low TrFE molar content is proposed. Fine‐tuning of the structure through thermal annealing in a vacuum environment significantly favors robust and highly polarized polymer films with a large area. Electric poling combined with an optimal annealing temperature (110–120 °C) gives highly ordered ferroelectric crystalline domains in the polymer films. Consequently, this remarkably broadens the temperature range (roughly up to 140 °C) for which the polymer film still presents high pyroelectric properties (pyroelectric coefficient 50 µC (m2K)−1). This study provides an alternative choice for pyroelectric polymer films with enhanced pyroelectricity in applications that require wider temperature ranges.

A molecular genetic toolkit for the differential expression analysis of soybean β-conglycinin subunit genes

The majority of proteins in soybean seeds are storage ones, including β-conglycinin and glycinin, which are necessary for seed germination. At the same time, they are the most valuable soy proteins used in the food industry, since their subunit composition and proportion of total protein can affect the quality of the resulting food product. β-conglycinins are trimers with different composition of subunits which are designated as α', α, β and encoded by the CG-1, CG-3, and CG-4 genes, respectively. The PCR analysis employed a model soybean cultivar ‘Sentyabrinka’. A complementary DNA synthesized from the RNA isolated from seeds of the studied cultivar served as a template. The in silico created pairs of primers for CG-1, CG-3, and CG-4 gene transcripts were used. As the result of PCR and the analysis of the obtained electrophoregrams, optimal annealing temperatures of primers for the CG-1, CG-3 and CG-4 genes were selected, at which only the characteristic fragment was observed. Thus, a molecular genetic toolkit has been developed for a comprehensive study of the qualitative and quantitative composition of soybean protein and can be used for further analysis of differential expression of genes responsible for the synthesis of β-conglycinin subunits.

A droplet digital PCR method for the detection of scale drop disease virus in yellowfin seabream (Acanthopagrus latus).

In this study, a ddPCR method for the detection of scale drop disease virus (SDDV) in yellowfin seabream (Acanthopagrus latus) was established based on Real-time fluorescence quantitative PCR detection methods and principles. The reaction conditions were optimized, and the sensitivity, specificity, accuracy, and reproducibility were assessed. The results showed that threshold line position was determined to be 1900 by the ddPCR method; the optimum annealing temperature for SDDV detection by the ddPCR method was 60°C; the limit of detection was 1.4-1.7 copies/μL; the results of specific detection of other common viruses, except for SDDV specific amplification, were all negative; and the relative standard deviation (RSD) for the reproducibility validation was 0.77%. The samples of yellowfin seabream (Acanthopagrus latus) liver, spleen, kidney, heart, intestine, brain, blood, muscle, skin and ascites with three replicates, respectively, were tested using the ddPCR method, and the results were consistent with clinical findings. The ddPCR method established in this study has the advantages of high sensitivity, high specificity, good reproducibility and simple steps for the quantitative detection of SDDV, which could be used for the nucleic acid detection of clinical SDDV samples, and provided a new quantitative method for the diagnosis of yellowfin seabream SDDV in the early stage of pathogenesis.

Study on the effect of annealing temperature on the optical characteristics and microstructure of Sb2Se3 thin films

To achieve high conversion efficiency in Sb2Se3 thin films, the effects of different annealing temperatures on the optical properties and microstructure were investigated. The experiment shows that annealing improves Sb2Se3 films' refractive index, absorptivity, and reduces the optical band gap. The first-principle theoretical analysis reveals that defects in the films such as SbSe2, SbSe3, VSe2, and VSe3 significantly affect their optical band gap. Based on the XRD (X-ray diffraction) patterns, the half-height widths, average grain sizes, microstrains and dislocation densities of the diffraction peaks have been calculated. The results show that the optimal annealing temperature is 325 °C. Finally, EDS (Energy Dispersive Spectrometer) and Raman spectroscopy were used to explain the reasons for the changes in the optical properties and internal structure of the film with the annealing temperature from the perspectives of the changes in the film components and the bonding properties between the atoms.

Critical factors for enhancing electrical performance in LaGdO3 capacitor

This study investigates the characteristics of metal/LaGdO3/Si capacitors using LaGdO3 as the dielectric material. LaGdO3 thin films were deposited using radio-frequency magnetron sputtering, and the effects of different process parameters, such as annealing temperature, electrode materials, and oxygen ratio, on the capacitance characteristics were investigated. Results showed that the presence of oxygen vacancies affects the dielectric constant, flat-band voltage, and breakdown field of LaGdO3 films. The optimal annealing temperature for the LaGdO3/Si stack was identified to be 600 °C, resulting in a dielectric constant of 13.9 and a flat-band voltage shift of 0.1 V. Introducing 10 % O2 during deposition effectively repaired oxygen vacancies in the film, while excessively high oxygen proportions resulted in a lower dielectric constant and a higher flat-band voltage shift. Moreover, the electrode material was found to affect the capacitance characteristics. The dielectric constants for Al/LaGdO3/Si, Ti/LaGdO3/Si, and Pt/Ti/LaGdO3/Si capacitors were 10.0, 16.3, and 17.3, respectively. The flat-band voltage shifts were −0.7, −0.42, and −0.03 V, with hysteresis voltages of 345, 117, and 32 mV, respectively. The Pt/Ti/LaGdO3/Si device exhibited the lowest oxide defect density, indicating superior interface quality and potentially enhanced device performance. In addition, the band diagrams for metal/LaGdO3/Si were constructed. This study demonstrates that oxygen vacancies and electrode materials are crucial factors influencing the capacitance characteristics of LaGdO3 films. The electrical properties of LaGdO3 films can be effectively improved by controlling process parameters, enhancing their potential for applications in capacitors and other electronic devices.

Synthesis of MgB2 films on Hastelloy-C276 tape with Al2O3/Y2O3/MgO/LaMnO3 buffer layers by magnetron sputtering in co-evaporation mode

This study presents the initial results of developing a technology for synthesizing a flexible superconducting magnesium diboride composite on a Hastelloy®-C276TM substrate coated with Al2O3/Y2O3/MgO/LaMnO3 buffer layers. The superconducting composite was deposited by magnetron sputtering from two Mg and B targets, followed by vacuum annealing at various substrate temperatures ranging from 400 °C to 700 °C. The superconducting transition temperature T c ≈ 22 K, with a transition width ΔT ≈ 1 K, and critical current J c ≈ 500 kA cm−2 (T= 5 K, H = 2 T) and J c ≈ 11 kA cm−2 (T = 15 K, H = 2 T) at the optimal annealing temperature of 400 °C.

A simple PCR-based quick detection of the economically important oriental fruit fly, Bactrocera dorsalis (Hendel) from India.

The oriental fruit fly, Bactrocera dorsalis (Hendel), is a significant economic and quarantine pest due to its polyphagous nature. The accurate identification of B. dorsalis is challenging at the egg, maggot, and pupal stages, due to lack of distinct morphological characters and its similarity to other fruit flies. Adult identification requires specialized taxonomist. Existing identification methods are laborious, time consuming, and expensive. Rapid and precise identification is crucial for timely management. By analyzing the variations in the mitochondrial cytochrome oxidase-1 gene sequence (Insect barcoding gene), we developed a species-specific primer (SSP), DorFP1/DorRP1, for accurate identification of B. dorsalis. The optimal annealing temperature for the SSP was determined to be 66°C, with no cross-amplification or primer-dimer formation observed. The SSP was validated with B. dorsalis specimens from various locations in northern and eastern India and tested for cross-specificity with six other economically significant fruit fly species in India. The primer specificity was further confirmed by the analysis of critical threshold (Ct) value from a qPCR assay. Sensitivity analysis showed the primer could detect template DNA concentrations as low as 1 pg/µl, though sensitivity decreased at lower concentrations. Sequencing of the SSP-amplified product revealed over >99% similarity with existing B. dorsalis sequences in the NCBI GenBank. The developed SSP reliably identifies B. dorsalis across all developmental stages and sexes. This assay is expected to significantly impact pest identification, phytosanitary measures, and eradication programs for B. dorsalis.

Development of a 1-step multiplex PCR assay for the detection of S. Enteritidis, S. Pullorum, S. Typhimurium, and S. Infantis associated with poultry production

Salmonellosis in poultry is detrimental to the advancement of the breeding industry and poses hazards to human health. Approximately 2,600 Salmonella varieties exist, among which S. Enteritidis, S. Pullorum, S. Typhimurium, and S. Infantis are prevalent serotypes in the poultry industry in recent years. They can also infect humans by contaminating poultry eggs and meat. Therefore, identifying these serotypes is crucial for successful preventive and control interventions. The White-Kauffmann-Le Minor scheme is time-consuming and requires expensive reagents. Whole-genome sequencing (WGS) and other molecular biology techniques require skilled technical staff. In comparison, the polymerase chain reaction (PCR) is more accurate, rapid, and inexpensive, thus proving suitable for widespread application in the poultry industry. Here, we selected 4 specific primers: lygD, mdh, ipaJ, and SIN_02055, which correspond to detecting S. Enteritidis, S. Typhimurium, S. Pullorum, and S. Infantis, respectively. They were integrated into a 1-step multiplex PCR method. We optimized the PCR method by utilizing specificity test results to determine the optimal annealing temperature (57°C). The PCR method exhibited excellent sensitivity for genomic DNA and bacterial cultures. We used the developed method to determine 157 clinical Salmonella isolates from various stages of the poultry production chain. The results aligned with serotype data generated via WGS analysis, demonstrating the method's excellent accuracy. In conclusion, this study developed a 1-step multiplex PCR method that simultaneously identifies S. Enteritidis, S. Typhimurium, S. Pullorum, and S. Infantis, allowing routine mass detection in the grass-root poultry industry.

Enhanced Hard Magnetic Performance for MnBi Green Powders

Mn55Bi45 melt - spun ribbons were prepared by using the melt-spinning technique followed by annealing in Ar/5%H2 gas mixture. The in-situ formation of ferromagnetic phase (denoted as LTP) of MnBi was observed by the multi-section cycled Differential Scanning Calorimetry (DSC) method. It was found that, the optimal annealing temperature range for forming MnBi LTP is 250 – 280 oC. The prolonging annealing time increases the content of MnBi LTP leading to the increase of saturation magnetization Ms but paid by the drop of the intrinsic coercivity iHc. The MnBi green powders were prepared by the Low Energy Ball Milling method (LEBM) in N2 liquid. The maximum energy product of MnBi green powders is estimated about 10.8 MGOe.

Effect of Varying Temperatures on the Electrochemical Performance of Lithium‐Ion Batteries Using LiNi0.3Mn0.3Co0.3Ti0.1O2 Cathode Materials

AbstractLiNi1/3Mn1/3Co1/3O2 (NMC 111) materials show promise as cathodes for lithium‐ion batteries (LIBs). However, their widespread use is hampered by various technical challenges, including rapid capacity fading and voltage instability. The cathode materials synthesized using the combustion method were annealed at various temperatures ranging from 650 to 900 °C for 24 h. In this study, we identified an optimal annealing temperature of 750 °C for LiNi0.3Mn0.3Co0.3Ti0.1O2 (NMCT) materials. NMCT‐750 exhibits an initial discharge capacity of about 140.1 mAh g−1 and retains the capacity of 91 % after 30th cycles. The good performance of NMCT‐750 is directly attributed to reduced cation mixing and the establishment of a stable structure with small particle sizes. In contrast, higher annealing temperatures (850 °C) lead to a rapid increase in primary particle size and result in poor cycling stability. Therefore, NMCT‐750, annealed at 750 °C, holds great potential as a cathode material for the next generation of LIBs.

Environmental DNA assays for Laricobius beetles (Coleoptera: Derodontidae), biocontrol agents of the hemlock woolly adelgid in North America.

The hemlock woolly adelgid, Adelges tsugae Annand (Hemiptera: Adelgidae), is an invasive pest causing significant ecological and economic damage to certain hemlock tree (Tsuga (Endlicher) Carrière, Pinales:Pinaceae) species. In response to this invasive threat, biological control strategies have been implemented, introducing natural predators such as Laricobius nigrinus Fender (Coleoptera: Derodontidae) and, more recently, Laricobius osakensis Montgomery and Shiyake (Coleoptera: Derodontidae), as specialist predators against A. tsugae. However, the genetic and morphological similarities between L. osakensis and both L. nigrinus and the native beetle, Laricobius rubidus LeConte (Coleoptera: Derodontidae), pose challenges in their identification. Effective monitoring of released predators is integral to evaluating the success of biological control measures. Environmental DNA (eDNA) holds potential for various detection applications, including species monitoring. In this study, we developed specific primers and probes targeting the mitochondrial cytochrome oxidase 1 gene sequences, achieving high specificity despite their 95% sequence similarity. With an optimal annealing temperature of 60 °C, our tools effectively differentiated L. osakensis from the other 2 beetles and demonstrated eDNA detection sensitivity down to 2 copies/µl. This research underscores the potential of precise molecular tools for advancing biological control and biodiversity assessment against invasive threats like A. tsugae.

Optimization of Annealing Temperature and Primer Concentration for Detection of Mycobacterium Tuberculosis Isoniazid Resistance Real-Time PCR Method

Indonesia has the second highest number of TB cases in the world according to the WHO report in 2022. Eradication of the National TB Program is difficult due to the presence of Mycobacterium tuberculosis (M. Tb) bacteria that are resistant to various anti-tuberculosis drugs (OAT) known as Multidrug- Resistant Tuberculosis (MDR-TB). Therefor, currently, a nucleic acid-based diagnostic kit has been developed that is designed to directly detect the presence of resistance to INH with mutations of the KatG gene codon 315 (S315T, S315N, S315I, S315R, S315G, R463L) and rifampicin sensitive M. Tb using the Real-Time PCR method. PCR components that are important for development include annealing temperature and primer concentration. This study aims to determine the optimum annealing temperature and primer concentration. The type of research is the Quasi Experiment. The treatment in this study is by adding each primer that varies in concentration, namely 200nM-400nM while varying the annealing temperature with a range of 52-62°C according to the Tm of each primer. The data obtained from this research are Ct values ​​from the target genes S315T, S315N, S315I, S315R, S315G, R463L and M. Tb Rifampicin sensitive.

Tuning of interface quality of Al/CeO2/Si device by post-annealing of sol-gel grown high-k CeO2 layers

A comprehensive study has been done on the influence of post-deposition annealing temperature on high-k cerium oxide (CeO2) layer grown on n-type silicon (Si) substrate and its resultant interface states have been studied for Al/CeO2/Si metal-oxide-semiconductor (MOS) devices. The high-k CeO2 thin films were deposited by spin-coating and sintered at different annealing temperatures (Ta) in the range of 400–900 °C. The parameters such as fixed charge density (Qeff), dielectric constant (k) of the layers, flat-band voltage (VFB), interface defect density (Dit), etc., of the MOS device were evaluated from CV and I-V measurements. A minimum value of flat band shift (∼0.05 V) with lower Qeff (−4.81 × 1011 C/cm2) have been achieved for the Ta of 600 °C. The k and Dit were evaluated to be 22 and 1.29 × 1012 cm−2, respectively at the Ta of 600 °C. In addition, the CV measurements showed a very small hysteresis and very low frequency dispersion for the Ta of 600 °C sample. Energy distribution of defect states was evaluated and it was maximum towards the bottom of the conduction band. This shows that the 600 °C is the optimum annealing temperature, which results in high quality interface, and the electron affinity of the corresponding CeO2 layers was found to be 3.29 eV as evaluated from ultraviolet photoelectron spectroscopy (UPS). Further, a maximum value of minority carrier lifetime (147 μs) has been achieved for the samples annealed at Ta of 400 °C, indicating that the post-annealing temperature plays a significant role on the properties of CeO2 films deposited by sol-gel process. Thus, the present study demonstrates the possibility of sol-gel grown high k-CeO2 layers suitable for MOS like devices.

A Molecular Dynamics Study on the Defect Formation and Mechanical Behavior of Molybdenum Disulfide under Irradiation.

Due to its appealing characteristics, molybdenum disulfide (MoS2) presents a promising avenue for the exploration of lubrication protection materials in high-energy irradiation scenarios. Herein, we present a comprehensive investigation into the defect behavior of multilayer MoS2 under argon (Ar) atom irradiation leveraging molecular dynamics simulations. We have demonstrated the energy shifts and structural evolution in MoS2 upon irradiation, including the emergence of Frenkel defects and intricate defect clusters. The structural damage exhibits an initial increase followed by a subsequent decrease as the incident kinetic energy increases, ultimately peaking at 2.5 keV. Moreover, we investigated the effect of postannealing on defect recovery and conducted the uniaxial tensile and interlayer shearing simulation in order to provide valuable insights for the defect evolution and its impact on mechanical and tribological properties. Furthermore, we have proposed the optimal annealing temperature. The current study reveals the atomic mechanisms underlying irradiation-induced damage on the structural integrity and mechanical performance of MoS2, thereby providing crucial guidance for its vital application in nuclear reactors and aerospace industries.

Investigating the effect of calcination temperature on the electrochemical properties of Na4MnV(PO4)3/NC@CNTs cathode materials for sodium ion batteries

Manganese-based NASICON-type Na4MnV(PO4)3 (NVMP) is used as an alternative material to the cathode materials (Na3V2(PO4)3) for sodium-ion battery (SIBs). By selecting the cheap and easily available and environmentally non-polluting Mn element to replace part of the highly toxic and expensive V element, it has the advantages of higher voltage platform, lower cost and weaker toxicity. However, the low intrinsic conductivity and poor cycling stability of NVMP severely limit its application in SIBs. In this paper, N-doped double carbon layer-coated NVMP composites (NVMP/NC@CNTs) are prepared by adding additional urea as a nitrogen source and CNTs as a carbon source using a simple and feasible sol-gel synthesis method, which improves their electronic conductivity and structural stability. On this basis, the effects of calcination temperature on the lattice structure, specific surface area, carbon disorder, Na+ diffusion coefficient (DNa+) and electrochemical properties of NVMP/NC@CNTs composites are mainly investigated. The results show that the optimal annealing temperature is 650 °C, and the NVMP/NC@CNTs material has the highest discharge capacity (105.6 mAh g−1 at 0.1C), the best rate performance (75.7 mAh g−1 at 5C), and the most stable cycling stability (79.4 %/89.3 % for 500 cycles at 1C / 5C, respectively). Even at high rate of 10C, an impressive cycling stability (77.5 % capacity retention over 1500 cycles). The sodium storage mechanism, electrochemical performance and pseudo-capacitance contribution of NVMP/NC@CNTs-650 are further investigated by kinetic analysis, GITT test, ex-situ XPS, XRD and EIS characterization. Finally, the assembled NVMP/NC@CNTs-650 || hard carbon (HC) full cell manifests a high capacity of 87.2 mAh g−1 with capacity retention of 92.5 % over 50 cycles at 1C. The results reveal that the appropriate annealing temperature can help to prepare electrochemically excellent and structurally stable NVMP composites, while the co-modification of N-doped dual-nanocarbon can produce a large number of defects and active sites, which is expected to facilitate the commercialization of SIBs.

Development of Bacillus subtilis Detection Method Targeting Genes codY, narH, and ureC Using Polymerase Chain Reaction

Bacillus subtilis, a causative agent of foodborne illness in bread, cakes, cereals, and cheese leading to symptoms like diarrhea and nausea, was investigated for its role in nosocomial infections, including endocarditis, bacteremia, septicemia, and meningitis. The research focused on three genes: codY, narH, and ureC, which respectively contribute to bacterial survival through biofilm and spore formation, acid resistance, and adaptation to anaerobic conditions. The objective of this study was to evaluate the codY, narH, and ureC genes using the Gradient PCR method for Bacillus subtilis detection in bread and cheese through Real-Time PCR. During the research, bacterial growth was observed with an OD600 of 1.438 in Tryptic Soy Broth (TSB), and colonies of medium size, smooth, cream-coloured, and round shape were successfully isolated on Tryptic Soy Agar (TSA). The DNA template used had a 71.5 ng/µL concentration with an A260/280 ratio of approximately 1.830. The annealing temperature for Gradient PCR used was 53-62°C. The primers successfully amplified codY (175 bp), narH (222 bp), and ureC (153 bp) gene amplicons. The optimal annealing temperature for the primers used was 60°C, as indicated by the presence of a single bright band in electrophoresis. Using these three different genes, testing can also be conducted with the Multiplex PCR method. The next step involves developing a detection kit using optimized primers and annealing temperatures for the identification of Bacillus subtilis in bread and cheese samples using Real-Time PCR.

Modulating oxygen vacancy of ZnO for visible-light driven photocatalytic H2 evolution via facile gas treatment approach

Photocatalytic hydrogen production through water splitting is one of the most promising approaches for sustainable and renewable energy source. In recent years, research on defect rich metal oxide semiconductors has increased tremendously. N-type semiconductor ZnO exhibits a wide direct band gap of 3.3eV, limiting the optical absorption at UV range, hindering the photocatalytic performance of pristine ZnO. Furthermore, short charge carriers life time can also decrease the efficiency for hydrogen evolution. In this report, crystal defect engineering via oxygen vacancy tailoring was conducted, narrowing the bandgap of ZnO, while creating interstitial defects that reduces the recombination rate of electrons and holes. ZnO was synthesized via hydrothermal method using zinc acetate dihydrate and sodium hydroxide as precursors before subjecting for conditional annealing for 30, 60, 90 and 120 min for 200 °C, 300 °C, 400 °C and 500 °C. A series of characterization techniques were used to authenticate the effects of oxygen vacancy in ZnO. Experimental studies revealed that ZnO annealed at 400 °C for 120 min exhibit the highest amount of hydrogen produced through photochemical reactions. Therefore, the degree of oxygen vacancies in ZnO semiconductor can be regulated through diligent control of annealing parameters. Specifically, finding the optimum annealing temperature and duration were the focus in this study that relates to its photocatalytic hydrogen evolution rate.