Particle Size Of ZnO Research Articles

Comparison of ZnO Nanoparticles Prepared by Spray Pyrolysis and Consecutive Method for UV-Driven Photocatalytic Degradation of Methylene Blue

ZnO is a semiconductor material that is widely used for many applications in industries such as solar cells, dye-sensitized solar cells, food packaging, photocatalytic, anti-microbial, light-emitting diode devices, and gas sensors. In this study, ZnO nanoparticles (NPs) have been successfully synthesized using two methods, namely spray pyrolysis and a consecutive method. The consecutive method is a combination of sol-gel and spray drying methods. The objective of this study is to investigate the photocatalytic performance of ZnO fabricated using those methods. Both methods used the same precursor, zinc acetate dehydrate as a source of zinc, but with different solvents and additives. Based on the X-ray diffraction pattern, the ZnO NPs synthesized using spray pyrolysis and a consecutive method exhibited similar polycrystalline hexagonal wurtzite structures. The large crystal sizes of ZnO NPs were obtained using a consecutive method, sol-gel followed by spray drying, in comparison with those from the ZnO spray pyrolysis. In contrast, the particle size of ZnO prepared by the consecutive method was in a smaller range. The SEM analysis implied that the ZnO structures had surface defects. In the UV-driven photocatalytic degradation of methylene blue, ZnO produced by the consecutive method exhibited slightly higher degradation performance than ZnO spray pyrolysis. This performance was attributed to the larger crystal size of ZnO NPs, which provided a longer carrier movement at semiconductor surfaces and reduced electron-hole recombination. Additionally, ZnO NPs produced using the consecutive method underwent agglomeration that leads to a smaller contact surface with methylene blue, obstructing the degradation process.

Effect of glucose addition on the morphology and activity of ZnO supported on mesoporous zeolite SBA-15 for the removal of hydrogen sulfide

Zinc oxide with its high equilibrium constant for sulfidation, can be utilized to purify H2S-containing gases, but its low kinetics at room temperature limits its sulfur loading capacity. This study use glucose as an organic additive and carbon source to prepare carbon doped ZnO adsorbents with different ZnO loadings (5-20wt%) through initial wet impregnation. It was observed that the sulfur capacity of 15wt% Zn/SBA-15-G (10.9mg/g) was approximately 1.65 times higher than that of 15wt% Zn/SBA-15 (6.6mg/g). This improvement was attributed to the use of glucose, which led to better ZnO dispersion, a narrower distribution of ZnO particle size, and the formation of C-O-Zn bonds that increased the number of hydroxyl groups on the ZnO surface. DFT calculations also indicated that carbon doping could lower the activation energy of the reaction between ZnO and H2S and shorten the reaction pathway. Consequently, the prepared ZnO adsorbent demonstrated enhanced desulfurization efficiency at room temperature. Furthermore, regeneration experiments conducted on the desulfurizer after use revealed that achieving complete regeneration is a challenge.

Quercus ballot as an innovative feedstock for biodiesel production using ZnO nanocatalyst

Selecting non-edible plant seed oil remains the best choice for biodiesel production using an effective nanocatalyst. In this study, the ZnO was prepared as a nanocatalyst using an aqueous extract from the Alhaji marorum plant. Nano ZnO has shown high catalytic activity, is cost-effective, environmentally friendly and converts triglycerides into fatty acid methyl esters. The results indicate that ZnO nanocatalyst exhibit a high specific surface area (146.82 m2 g-1), large pore volume (0.35 cm3 g-1), and an average crystallite size of 42.3 nm. The FESEM analysis shows that the particle size of ZnO lies in the range of 30–50 nm with a rod shape and densely packed morphology. The biodiesel is produced using a transesterification process from novel non-edible Quercus ballot plant seeds. The resulting biodiesel has a 98.06 % yield under a methanol/oil ratio of 6:1 with 0.5 wt% ZnO nanocatalyst at 65 °C for 80 min. It is established that the methanol-to-oil ratio and the catalyst concentration significantly affect the transesterification reaction. The biodiesel produced is characterized by GC–MS to determine its exact composition and FTIR is used to confirm functional groups and is evaluated according to ASTM D6751.

Molecular dynamics mechanism of incorporating ZnO with varying particle sizes into ECTFE coatings and its impact on corrosion resistance

A composite coating of zinc oxide/chlorotrifluoroethylene copolymer (ZnO/ECTFE) was prepared on the surface of carbon steel via electrostatic spraying and heat treatment at 260 ℃. The influence of ZnO particle size variations on the anticorrosive properties of ECTFE coating was investigated by characterizing the microstructure, adhesion, hydrophilic/hydrophobic properties, electrochemical corrosion performance, as well as the dynamics simulation analysis on water molecule and chloride ions diffusion in the coating. The results show that the ECTFE coating incorporated with 100nm ZnO has the highest surface roughness (Roughness coefficient Ra = 30.6nm), the most robust adhesion (Bonding pull-out strength = 5.22MPa), and the lowest corrosion current density after a 90-day immersion (Icorr,90d = 4.05 × 10⁻⁸ A∙cm⁻²). These improvements represent an increase of 81.67% and 59.9% compared to the pure copolymer coating (Icorr,90d = 2.21 × 10⁻⁷ A∙cm⁻²) and the coating incorporated with 200nm ZnO (Icorr,90d = 1.01 × 10⁻⁷ A∙cm⁻²), respectively. This phenomenon can be attributed to the addition of small-sized ZnO, which enhances the density of the coating, induces a hydrophobic transition on its surface, strengthens the double electric layer effect, thereby improving its resistance against water molecule and chloride ions diffusion and ultimately enhances the corrosion resistance.

Effect of ZnO particle size on the radiation shielding efficiency of B2O3–BaO–ZnO glass system

Abstract This study analyzes the ZnO particle size’s effect on glass samples’ radiation shielding ability. Four glass samples with differing micro and nanoparticle ZnO content were investigated at four energies, 0.060, 0.662, 1.173, and 1.333 MeV. The investigated glasses are a B2O3–BaO–ZnO glass system and are composed of 30 % micro ZnO (30 M), 20 % micro ZnO and 10 % nano ZnO (20 M−10 N), 10 % micro ZnO and 20 % nano ZnO (10 M−20 N), and lastly 30 % nano ZnO (30 N). The theoretical XCOM software was employed to validate the experimental LAC values of the glasses, revealing that for at all energies, the values obtained from the two methods agreed with each other well. The glasses’ HVL, MFP, and RSE were then compared. The HVL values at all energies decreased as more nano ZnO was introduced into the glass system, reaching a minimum of 1.947 cm at 0.662 MeV for the 30 N sample. This sample also had the lowest MFP at all energies, while the 30 M glass had the highest, such as 0.088 and 0.070 for 30 M and 30 N respectively at 0.060 MeV. The RSE of a 1 cm thick sample of each of the glasses was tested and found that the 30 N sample exhibited the greatest RSE. The relative percent deviation between the 30 N and 30 M glasses was also analyzed, which highlighted the difference between 30 N’s greater LAC values compared to 30 M at all energies.

Integrated Approach to the Optimization, Synthesis, Fabrication, and Application of ZnO-Based Sensors for Portable LPG Leakage Detection Systems

Liquefied petroleum gas (LPG) is used for cooking as well as in vehicles in the form of compressed natural gas (CNG) and in industries. As gas is volatile, there is the possibility of leakage which will be turned into take explosion or fire. It is a keen need to use the detection system for gas leakage for security purposes. ZnO thick film sensor was synthesized and fabricated by using the standard screen-printing method. The XRD pattern revealed that the ZnO thick film was polycrystalline, with an average crystallite size of around 27.1174 nm. The SEM scan revealed a ZnO particle size of around 1.88�m. Additionally, electrical and thermal properties were examined. This paper discussed the synthesized ZnO thick film LPG gas leakage detector prototype using Arduino ATMEGA8.

Synergy of functionalized activated carbon and ZnO nanoparticles for enhancing photocatalytic degradation of methylene blue and carbaryl

This study proposes preparing ZnO and ZnO/activated carbon (AC) for photocatalytic applications. ZnO and AC were synthesized using precipitation and carbonization processes, respectively. Particle sizes of ZnO and ZnO/AC were estimated at 121–135 nm. The crystalline structure analysis confirmed the presence of hexagonal wurtzite structures in ZnO. Microcrystalline graphite and amorphous carbon structures were observed in AC. The combination of these characteristics was observed in ZnO/AC. ZnO/AC exhibited an increase in surface area from 25.36 to 29.86 m2/g and a decrease in pore diameter from 5.66 to 4.31 nm. The chemical states of ZnO and AC remained unchanged. Therefore, the nanocompound structure of ZnO/AC can be inferred. The ZnO/AC nanocompounds were then employed to degrade methylene blue (MB) dye and carbaryl (CBR) insecticide, demonstrating excellent photocatalytic performance compared to pure ZnO. The apparent degradation rate constant reached an average value of 3.49 × 10−3 and 16.25 × 10−3 min−1 for MB and CBR, respectively. AC functions as carrier collectors in the ZnO/AC nanocompound structures due to the suitable energy band level for facilitating electron and hole transfers. This results in recombination suppression and prolonged lifetime, thus enhancing photocatalytic activity. The finding suggests the potential use of ZnO/AC nanocompounds to degrade agricultural chemicals in contaminated natural water under sunlight.

Study of graphene incorporation into ZnO-PVA nanocomposites modified electrode for sensitive detection of cadmium

The presence of heavy metals often causes significant health risks, particularly cadmium, which is known for its high toxicity. In this study, a glassy carbon electrode was successfully modified by incorporating ZnO-PVA-Graphene nanocomposite, leveraging the excellent electrical properties and electron mobility of the material. Comprehensive material analysis, including XRD, confirmed that ZnO maintained its hexagonal wurtzite crystal structure despite the addition of graphene. Moreover, FESEM analysis showed that increasing graphene concentration led to a reduction in ZnO particle size by 85, 68, and 52 nm, respectively, accompanied by a decrease in band gap energy, as verified by UV–Vis measurements. Photoluminescence tests were also conducted and the result showed a noticeable blue shift in ZnO-PVA-Graphene nanocomposites compared to ZnO-PVA, specifically in the near band-edge (NBE) UV emission within the 374–379 nm wavelength range. Through I–V characterization, the optimal graphene concentration for cadmium detection was identified as 1.5 wt% in ZnO-PVA-Graphene nanocomposites, showing an approximate ohmic response. Meanwhile, square-wave voltammetry analysis of cadmium concentrations ranging from 0 to 80 ppm produced a coefficient of determination of 0.98926 and a Limit of Detection (LOD) of 9.88 ppm. These results showed the significant potential of ZnO-PVA-Graphene nanocomposites as a promising material for further development as an effective electrode modifier, enhancing the sensitivity of detection systems.

Study on the Synthesis of Nano Zinc Oxide Particles under Supercritical Hydrothermal Conditions.

The supercritical hydrothermal synthesis of nanomaterials has gained significant attention due to its straightforward operation and the excellent performance of the resulting products. In this study, the supercritical hydrothermal method was used with Zn(CH3COO)2·2H2O as the precursor and deionized water and ethanol as the solvent. Nano-ZnO was synthesized under different reaction temperatures (300~500 °C), reaction times (5~15 min), reaction pressures (22~30 MPa), precursor concentrations (0.1~0.5 mol/L), and ratios of precursor to organic solvent (C2H5OH) (2:1~1:4). The effects of synthesis conditions on the morphology and size of ZnO were studied. It was found that properly increasing hydrothermal temperature and pressure and extending the hydrothermal time are conducive to the more regular morphology and smaller size of ZnO particles, which is mainly achieved through the change of reaction conditions affecting the hydrothermal reaction rate. Moreover, the addition of ethanol makes the morphology of nano-zno more regular and significantly inhibits the agglomeration phenomenon. In addition to the change in physical properties of the solvent, this may also be related to the chemical bond established between ethanol and ZnO. The results show that the optimum synthesis conditions of ZnO are 450 °C, 26 MPa, 0.3 mol/L, 10 min, and the molar ratio of precursor to ethanol is 1:3.

Structural and optical properties of ZnO thin films as a function of pH value and its effect on photoelectrochemical water splitting

ZnO nanoparticles were synthesised via sol–gel method, and then, deposited on a glass substrate using the spin-coating procedure to hand in ZnO thin films. In order to study the effect of alkaline sol on different properties of ZnO thin films, the pH value of sol was adjusted with ammonia. Then, the structural, optical, and photoelectrochemical properties of the prepared samples were analysed. According to XRD analyses, by increasing pH values, the size of ZnO particles increases and the films’ crystallinity improves. In addition, SEM micrographs affirm the uniformity of thin films. According to AFM findings, the morphology and roughness of the samples’ surface are affected by pH values in such a way that with increasing the pH, the roughness of the surface decreases, and the crystallinity improves. Also, both UV–vis peaks shift towards lower wavelengths with increasing pH value of ZnO sol. This means that the more the pH values of ZnO sol, the more the excitation energy of electrons. On the other hand, the numerical values of the energy bandgap decrease by increasing pH. According to PL results, the increase of pH causes the separated electrons and holes to have more energy and can move away from each other. So, the recombination process rate decreases; this result affirms by EIS findings. Increasing the optical absorption and reducing charge recombination are in favour of the photocatalytic reactions. Clearly, increasing the pH value causes the stable photocurrent to increase and the threshold voltage of (J-V) diagram to decrease. Also, the samples show recognisable sensitivity to light. As a final result, the best suggested amount of pH to fabricate ZnO photoanods for water splitting is 10.5.

Floating ZnO nanoparticles-coated micro glass bubbles for the efficient photodegradation of micropollutants in water

This study proposes a novel approach to fabricate floatable ZnO-coated micro glass bubbles (MGBs) using cold plasma as a surface modification method. Pre-treating MGBs with cold plasma enhances surface wettability and roughness and the adhesion of ZnO nanoparticles on their surface. Based on the results, the photodegradation performance of ZnO-coated MGBs under simulated solar light is directly affected by the cold plasma pre-treatment time, the solution depth, and the amount of the floatable material on the contaminated solution surface. Furthermore, a higher concentration of zinc acetate in the coating process led to larger ZnO particle sizes and increased coating efficiency, but it resulted in lower coating stability on the surface of the MGBs. Remarkably, ZnO-coated MGBs under 10 h of simulated solar radiation achieved almost 100 % removal of a mixture containing seven different micropollutants (caffeine, sulfamethoxazole, trimethoprim, carbamazepine, atrazine, naproxen, and ibuprofen) commonly detected in aquatic environments. Finally, ZnO-coated MGBs demonstrate excellent reusability and stability, suggesting their viability as a sustainable option for efficiently degrading organic pollutants in water.

Synthesis of phytogenically deposed Ag nanospheres on ZnO nanosheets for photocatalytic and catalytic applications

Current study presents the phytogenic deposition of metallic Ag nanospheres on ZnO nanosheets to produce Ag/ZnO nanostructures using Jacobaea Maritima (Silver Ragwort) plant extract and the prepared materials were tested for the photo-mineralization of methylene blue (MB) dye and catalytic reduction of nitroaromatics i.e. 4-nitroaniline (4-NA) and 4-nitrophenol (4-NP) in the presence of NaBH4 solution. The mean grain size and crystallinity of ZnO particles in Ag/ZnO nanostructures were found to be increased while the particle strain and dislocation density decreased with the elevation of Ag level in ZnO, and band gap energy value was reduced that has improved the photodegradation efficiency for MB dye from 45% to 98.60%, however, an excess amount of Ag has suppressed the photo-activity of Ag/ZnO nanostructures due to increase of band gap value and coverage of ZnO nanocrystals by Ag clusters. The catalytic reduction process indicated that the 4-NA and 4-NP were almost decolorized within 8 and 10 min, respectively. The degradation reaction rate of MB dye was enhanced by ∼7 times for Ag/ZnO nanostructures in comparison to pure ZnO nanosheets. The trapping experiments established that the •O2− and •OH radicals were the key active entities engaged in the deprivation of MB dye.

Zinc Oxide and Magnesium-Doped Zinc Oxide Nanoparticles Ameliorate Murine Chronic Toxoplasmosis.

Toxoplasma gondii causes a global parasitic disease. Therapeutic options for eradicating toxoplasmosis are limited. In this study, ZnO and Mg-doped ZnO NPs were prepared, and their structural and morphological chrematistics were investigated. The XRD pattern revealed that Mg-doped ZnO NPs have weak crystallinity and a small crystallite size. FTIR and XPS analyses confirmed the integration of Mg ions into the ZnO framework, producing the high-purity Mg-doped ZnO nanocomposite. TEM micrographs determined the particle size of un-doped ZnO in the range of 29 nm, reduced to 23 nm with Mg2+ replacements. ZnO and Mg-doped ZnO NPs significantly decreased the number of brain cysts (p < 0.05) by 29.30% and 35.08%, respectively, compared to the infected untreated group. The administration of ZnO and Mg-doped ZnO NPs revealed a marked histopathological improvement in the brain, liver, and spleen. Furthermore, ZnO and Mg-doped ZnO NPs reduced P53 expression in the cerebral tissue while inducing CD31 expression, which indicated a protective effect against the infection-induced apoptosis and the restoration of balance between free radicals and antioxidant defense activity. In conclusion, the study proved these nanoparticles have antiparasitic, antiapoptotic, and angiogenetic effects. Being nontoxic compounds, these nanoparticles could be promising adjuvants in treating chronic toxoplasmosis.

Improved ultraviolet photodetector performances using solution-processed nitrogen-doped carbon quantum dots/ZnO hybrid thin films

We fabricated the solution-processed photodetectors using the nitrogen-doped carbon quantum dots/zinc oxide (NCQDs/ZnO) hybrid films and characterized using ultraviolet (UV) spot-light of 365 nm at 1 mW/cm2. The NCQDs adsorbed onto the surface and/or grain boundaries of ZnO crystallites control ZnO particle size (by capping) in the NCQDs/ZnO hybrid thin films, resulting in the improved film quality and decreased the dark current in the devices. The NCQDs to ZnO [%(w/v)] ratio of 1.2 × 10−3 in the hybrid film UV photodetector exhibits the stable and reproducible photoresponses with the highest responsivity & external quantum efficiency (which are ∼3 times higher), and detectivity (∼7.5 times higher) than the pristine ZnO based photodetector, attributed to the effective transfer of photogenerated electrons from NCQDs to ZnO nanoparticles in the hybrid film. The solution-processed NCQDs/ZnO hybrid films will be very much useful to improve the UV photodetector performances for the cost-effective commercial applications.

Mn Doped ZnO Film for Ethanol Vapor Detection

It has become a major challenge to develop highly sensitive and selective ZnO gas sensors to detect the leakage of toxic and explosive gases due to their high operating temperature. This article reports the design, characterization, and application of a Mn-doped ZnO thin film for ethanol gas vapor detection at a relatively lower temperature. To achieve this, undoped (0%) and Mn doped ZnO thin films were prepared using a spin coating technique and their structural, morphological and optical characterizations were carried out using XRD, SEM, EDX and UV-vis spectrophotometer. The XRD analysis showed a polycrystalline ZnO structure with the preferred orientations along (100), (002), (101), (102), (110), (103), and (200) planes. Upon Mn doping, the average crystallite size and band gap of ZnO were found to be decreased, which indicated that Mn ions substitute into the lattice of ZnO. Interestingly, SEM images revealed the grainy like porous ZnO surfaces. The EDX results confirmed the presence of Mn dopant in the ZnO lattice. In the doped films, the changes in particle size and grain boundaries of nanocrystalline ZnO resulted changes in sensitivity and operating temperature of ZnO gas sensor. The sensitivity measurements towards ethanol vapor showed significant decrease of the operating temperature from 220°C to 160°C as Mn concentration was increased from 0 to 5%. As-prepared Mn-doped ZnO sensors will be useful for sensing ethanol vapor at relatively low temperature.

Synthesis of ZnO-TiO2 Nanoparticles by Sol-Gel Process and its Application for Solar Cell Semiconductor

ZnO-TiO2 semiconductor can be used in Dye-Sensitized Solar Cell (DSSC) devices as an alternative to renewable energy. This semiconductor can be synthesized by sol-gel method. The objective of this study is synthesizing the TiO2-doped ZnO nanoparticle semiconductors for DSSC devices with mangosteen peel extract dye. Avocado seeds were extracted with water, as a capping agent in the synthesis of ZnO-TiO2 (TiO2 ratio of 0,3,5,7 and 10% to ZnO). XRD results show the success of ZnO-TiO2 doping, due to the 2θ shift and changes in the crystal lattice. The average crystal size obtained was 33.7972 nm. The SEM results showed that the particle size of ZnO ranged from 45-100 nm. The UV-Vis dye measurements of mangosteen peel extract showed an absorption peak at 296-483 nm wavelength, with a corresponding band gap energy value of 3.04 eV. The UV-Vis DRS ZnO-TiO2 measurements have an average band gap energy of 3.1425 eV and ZnOof 3.1915 eV. The highest DSSC efficiency value is 2.15 x 10-2% at 7% ZnO-TiO2 semiconductor.

In-situ measurement of dynamic micro X-ray CT and dynamic mechanical analysis for rubber materials

Observing the internal state that takes place during deformation is essential for comprehending the mechanical properties of polymeric materials like rubber. For the effective utilization of rubber in damping applications, it is imperative to comprehend the relationship between the loss factor and microstructure. In an earlier study, we developed a dynamic X-ray CT technique tailored for damping materials subjected to tensile amplitude and proposed a method to directly evaluate the internal deformation behavior under dynamic conditions. However, owing to the technical constraints of the shaker employed for dynamic X-ray computed tomography, key variables such as vibration frequency and amplitude could not be incorporated into the analysis. Additionally, it has not been possible to simultaneously measure dynamic viscoelasticity and dynamic micro X-ray CT in situ.In this study, we developed an experimental system that enables simultaneous measurement of dynamic mechanical properties and dynamic X-ray computed tomography (CT). This system facilitates in-situ investigation of internal deformation behavior and the loss factor in rubber materials, allowing for the assessment of variations in loss factors at the micro-scale. We examined the differences between styrene butadiene rubber (SBR) and natural rubber (NR) as base materials and investigated the influence of shape, and particle size of ZnO on the dynamic behavior of SBR composites. Dynamic X-ray computed tomography (CT) was conducted at excitation frequencies of 1 and 2 Hz, excitation amplitudes corresponding to 1% and 1.25% of the inter-chuck distance of the specimens, and a spatial resolution of 0.5 µm. Local strains were extracted from the 3D reconstructed images, and both the local strain amplitudes and their histograms were assessed as characteristics of dynamic behavior. The results indicated that the effect of varying the excitation frequency between 1 and 2 Hz was minimal for the SBR. Additionally, the median value of local strain amplitudes shifted in relation to the magnitude of the excitation amplitude. When comparing base materials (SBR and NR) with significantly different loss factors, no discernible differences were observed in the histograms of local strain amplitudes. The histograms did vary based on the formulation conditions of the SBR microparticle composite, although the loss factor remained unchanged. This lack of change in the loss factor can be attributed to the minimal impact of the particulate composites on the inherent loss factor of pure SBR. Importantly, the study successfully achieved multimodal and simultaneous measurements using dynamic mechanical analysis and dynamic micro X-ray CT.

Synthesisation of Zinc Oxide Nanowires via Hybrid Microwave-Assisted Sonochemical Technique at Various Microwave Power

Zinc oxide nanowires (ZnO NWs) have been successfully synthesized via a hybrid microwave-assisted sonochemical technique (HMAST) using zinc acetate dehydrate as starting material. The optimized parameters were set at 12.5 mM solution concentration and a rapid deposition time of 60 minutes. The microwave power was varied from 100 to 800 Watts and the effect of microwave power on the morphological, structural, and optical properties ofthe ZnO NWs has also been studied. Results showed an aligned, uniformly distributed hexagonal wurtzite structure of ZnO NWs was produced, which were augmented at 600 W microwave power, having the smallest diameter size of 29.66 nm. The XRD graph showed that the ZnO NWs produced are highly crystalline, exhibiting the sharpest and narrowest intensity of (002) peaks and a crystallite size of 18.60 nm. The transmittance spectra obtained by UV-Vis would be 89.72%, having a sharp absorption edge, implying the lower particle size of ZnO as well as exhibiting high absorbance in the ultraviolet region, indicating good crystallinity. From the findings, it can be confirmed that the microwave-assisted method helped in improving the formation of higher quality ZnO NWs that can be befittingly applied in many devices such as photocatalysts and sensors due to their excellent electrochemical properties.

Study on the properties of low silver Sn1.0Ag0.5Cu composite solder reinforced with nickel-plated zinc oxide and its soldering joint

Based on the preparation of nickel-plated zinc oxide (Ni-ZnO) by pyrolysis-reduction method, low silver Sn1.0Ag0.5Cu lead-free composite solders reinforced with Ni-ZnO were prepared by the powder metallurgy method, and the microstructure and properties of the soldering joints were investigated accordingly. The results showed that the particle size of ZnO was reduced after ball milling. The Ni-ZnO reinforcement phase was successfully prepared by pyrolysis-reduction method, in which Ni particles with an average particle size of 9.7 nm were uniformly and densely deposited on the surface of ZnO particles, and the interface between ZnO (002) and Ni (111) showed a semi-coherent relationship with a mismatch of 0.203. The moderate addition of Ni-ZnO had little effect on the electrical conductivity of the Sn1.0Ag0.5Cu composite solders reinforced with Ni-ZnO. But it refined the primary β-Sn grains in the composite solders and improved the wettability and tensile strength of the composite solders. At an addition of 1.0 wt% Ni-ZnO reinforcement phase, the tensile strength and shear strength of the composite solder and its soldering joint reached a maximum value of 41.8 MPa and 28.9 MPa, with an increase of 39.3 % and 41.7 % respectively compared to the base solder material. The fracture position of composite solder/Cu soldering joint occurred in the transition zone of the soldering seam and IMC (Intermetallic Compound) layers. With the increase of Ni-ZnO reinforcement phase addition, the shear fracture location of the soldering joint moved from the near copper substrate side to the near soldering seam side in the transition zone, and the fracture mode gradually changed from a mixed ductile-brittle fracture to a typical ductile fracture dominated by parabolic toughness dimples.

Photocatalytic Reduction Efficiency of CO2 Depending on ZnO Particle Size

In the face of increasing global carbon dioxide emissions and the urgent need to mitigate climate change, the development of efficient and sustainable strategies for CO2 conversion has gained significant attention. One of the methods of eliminating the harmful effects of CO2 is its photoreduction. In this paper, ZnO was used as an effective photocatalyst for the photoreduction of CO2 in a gas-phase system. The influence of particle size on the process efficiency was investigated. The ZnO materials applied in the studies were characterized using XRD, SEM, and low-temperature nitrogen adsorption (BET) methods. The pore volume distribution was calculated based on the DFT method. The investigation confirmed that it had a significant impact on the formation of the product of photocatalysis carbon dioxide. The main identified product was carbon monoxide. Hydrogen and methane were detected as well. Based on the results, it was found that the process efficiency was enhanced with decreasing ZnO particle size, and the most effective catalyst for the photoreduction of CO2 was the ZnO sample with the smallest particle size (18 nm).