Large Oxygen Vacancies Research Articles

Bougainvillea glabra-mediated synthesis of Zr₃O and chitosan-coated zirconium oxide nanoparticles: Multifunctional antibacterial and anticancer agents with enhanced biocompatibility.

The effectiveness and safety of nanomaterials (NMs) are essential for their use in healthcare. This study focuses on creating NPs with multifunctional antibacterial and anticancer properties to combat bacterial infections and cancer disease more effectively than traditional antibiotics. This study investigates the synthesis of Zr3O and chitosan (ch) coated zirconium oxide nanoparticles (chZrO NPs) using Bougainvillea glabra (B. glabra) plant extract through a green, one-pot precipitation method. The synthesized NPs were analyzed using various techniques. Their antibacterial properties are attributed to the production of reactive oxygen species (ROS), influenced by their size, large surface area, oxygen vacancies, ion release, and diffusion capabilities. The chZrO NPs showed superior antibacterial activity compared to Zr3O and chitosan alone, with effective inhibition against both Gram-positive bacteria (S. aureus and B. subtilis) and Gram-negative bacteria (E. coli and P. aeruginosa). Additionally, anticancer studies of chZrO NPs demonstrated significant activity against colon cancer HCT116 cells with C50 values of 4.98 μg/mL compared to chitosan and Zr3O with 9.62, 6.69 μg/mL, while biocompatibility tests on L929 cells confirmed their safety showing 93 % cell viability compared to ch and Zr3O. These findings suggest that chZrO NPs are promising candidates for future use in clinical and healthcare applications.

Effect of Calcination Temperature in Large-Aperture Medium-Entropy Oxide (FeCoCuZnNa)O on CO2 Hydrogenation for Light Olefins

The catalytic hydrogenation of carbon dioxide is not only a way to mitigate the greenhouse effect but also provides high-value chemicals. In this work, a medium-entropy oxide catalyst (FeCoCuZnNa)O was prepared by the sol–gel method for highly active and selective hydrogenation of CO2 to value-added hydrocarbons. When reacted at 290 °C, 2.5 MPa, and 2500 mL·gcat−1·h−1, the CO2 conversion and selectivity of olefin were affected by the calcination temperature of the catalyst, and the best performances were 39% and 41.3%. The large pore size and oxygen vacancies (Ov) formed by (FeCoCuZnNa)O promote the activation of CO2 and promote the C-C coupling reaction of Fe5C2 in a hydrogenation reaction. The promoted C-C coupling reaction was related to the surface enrichment of iron species. The presence of Ov also inhibited the excessive hydrogenation reaction, further improving the selectivity of light olefins. In addition, (FeCoCuZnNa)O did not show significant deactivation within 75 h, indicating that the catalyst has strong industrial potential.

Recent Advances in Barium Cobaltite-Based Perovskite Oxides as Cathodes for Intermediate-Temperature Solid Oxide Fuel Cells.

Solid oxide fuel cells (SOFCs) are considered as advanced energy conversion technologies due to the high efficiency, fuel flexibility, and all-solid structure. Nevertheless, their widespread applications are strongly hindered by the high operational temperatures, limited material selection choices, inferior long-term stability, and relatively high costs. Therefore, reducing operational temperatures of SOFCs to intermediate-temperature (IT, 500-800°C) range can remarkably promote the practical applications by enabling the use of low-cost materials and enhancing the cell stability. Nevertheless, the conventional cathodes for high-temperature SOFCs display inferior electrocatalytic activity for oxygen reduction reaction (ORR) at reduced temperatures. Barium cobaltite (BaCoO3-δ)-based perovskite oxides are regarded as promising cathodes for IT-SOFCs because of the high free lattice volume and large oxygen vacancy content. However, BaCoO3-δ-based perovskite oxides suffer from poor structural stability, inferior thermal compatibility, and insufficient ionic conductivity. Herein, an in-time review about the recent advances in BaCoO3-δ-based cathodes for IT-SOFCs is presented by emphasizing the material design strategies including functional/selectively doping, deficiency control, and (nano)composite construction to enhance the ORR activity/durability and thermal compatibility. Finally, the currently existed challenges and future research trends are presented. This review will provide valuable insights for the development of BaCoO3-δ-based electrocatalysts for various energy conversion/storage technologies.

MOF-derived high-entropy oxides (YTbDyErYb)2O3 for boosted non-contact physiological humidity monitoring induced by oxygen vacancy modulation

In recent years, high-entropy oxides (HEOs) have gained significant attention due to their unique structure, yet the usage of HEOs in gas/humidity sensing is still a vast expanse of land worthy of vigorous cultivation. Here, HEOs were designed via high-entropy metal-organic frameworks (HE-MOFs) as sacrificial templates and then calcined at different temperatures to obtain (YTbDyErYb)2O3 (named as HEO-600, HEO-700 and HEO-800). After material characterization, as-synthesized HEOs were explored as humidity sensing materials for the first time at a relative humidity (RH) range of 11%-97%. The HEO-700 sensor exhibits the optimized properties featured in a response of three orders of magnitude (2.8 × 103) and extremely short response time (2 s). The excellent humidity sensing performance of HEO-700 can be attributed to the large surface area (39.6 m2/g) and abundant oxygen vacancies (53.1%). In addition, the HEO-700 sensor demonstrates great potential in real-time human physiological moisture detection, such as finger, breath, and non-contact switch. It is believed that this contribution provides attracting humidity sensing candidate for practical applications, and moreover, will provide inspiration for design of new HEOs in this emerging field of solid-state sensory devices.

Ternary electrochemiluminescence biosensor based on Ce2Sn2O7@MSN luminophore and Au@NiO-CeO2 as a co-reaction accelerator for the detection of prostate specific antigen

A ternary ECL system was constructed with Ce2Sn2O7@MSN composite as luminophore, potassium persulfate as co-reactant and Au@NiO-CeO2 as co-reaction accelerator to realize ultra-sensitive biosensing detection of prostate specific antigen (PSA). The abundant oxygen vacancies in Ce2Sn2O7 endow it with powerful electrochemical redox ability, accelerate energy transfer, and ensure Ce2Sn2O7 excellent electrochemical luminescence performance as a luminophore. Furthermore, to optimize the luminescence energy, enhance stability, and reduce the background signal to improve its signal-to-noise ratio, a highly selective Ce2Sn2O7@MSN biological probe was obtained by coating cerium stannate (Ce2Sn2O7) with mesoporous silica nanospheres (MSN). Au@NiO-CeO2 with a large specific surface area and high oxygen vacancy activity was synthesized as the co-reaction accelerator, which promoted the generation of SO4•− through the rapid reversible oxidation and reduction of Ce4+/Ce3+, thereby the ECL signal amplified effectively. Under optimal conditions, the linear detection range of PSA spans from 100fg mL−1 to 100 ng mL−1, with a remarkable lowest detection limit of 0.037pg mL−1, showcasing significant application potential. This study provides a valuable reference for pyrochlore to be used as luminophore in the detection of various biomarkers by ECL biosensing.

Bubble-induced self-assembly synthesis of defective hierarchical boehmite with ultra-high removal efficiency towards Congo red: Preparation and adsorption mechanism

To cope with the increasingly urgent environmental issue and provide promising alternative adsorbents, the synergistic preparation route of dissolution and bubble-induced self-assembly was firstly exploited to guide the reconstruction process of a defective hierarchical porous boehmite-microspheres (BMS) adsorbent in a favorable direction to improve the CR adsorption capacity using aluminium hydroxide industrial waste as raw materials. Multiple non-in-situ physicochemical characterization instruments demonstrate that BMS-4 adsorbent possesses abundant coordinatively unsaturated Al–species, large specific surface area, high porosity, oxygen vacancies and oxygen-containing groups, which promote the maximum adsorption capacities for CR up to 6805.08 ± 5.4 mg g−1. Moreover, the Pseudo-second order model and the Langmuir model are more suitable for describing the behavior of CR adsorption, which proves it is more inclined to be monolayer adsorption and there is no chemical reaction between CR and adsorbent. More importantly, it can be practiced in eight cycles of adsorption tests, achieving ultra-high stability for over 94.46 % of the original adsorption capacity. Combined with density-functional theory (DFT) calculations and experimental results, it is illustrated that the amino protonation is responsible for the additional enhancement of CR adsorption, in addition, oxygen vacancy capture and BMS-4/CR–SO3+–NH3 mechanism for enhanced adsorption of dyes is proposed, both of which show that bubble-induced self-assembly provides a promising route for the preparation of high-performance adsorbents.

Oxygen vacancy migration and impact on high voltage DC polarization in 0.8BaTiO3–0.2BiZn0.5Ti0.5O3

AbstractElectrical polarization and defect transport are examined in 0.8BaTiO3–0.2BiZn0.5Ti0.5O3, an attractive capacitor material for high power electronics. Oxygen vacancies are suggested to be the majority charge carrier at or below 250°C with a grain conduction hopping activation energy of 0.97 eV and 0.92 eV for thermally stimulated depolarization current (TSDC) and impedance spectroscopy measurements, respectively. At higher temperature, thermally generated electronic conduction with an activation energy of 1.6 eV is dominant. Significant oxygen vacancy concentration is indicated (up to ∼1%) due to cation vacancy formation (i.e., acceptor defects) from observed Bi (and likely Zn) volatility. Oxygen vacancy diffusivity is estimated to be 10−12.8 cm2/s at 250°C. Low diffusivity and high activation energies are indicative of significant defect interactions. Dipolar oxygen vacancy defects are also indicated, with an activation energy of 0.59 eV from TSDC measurements. The large oxygen vacancy content leads to a short lifetime during high voltage (30 kV/cm), high temperature (250°C) direct current (DC) electrical measurements.

Magnetically separable and visible light-driven photocatalytic activity of graphene oxide based α-Fe2O3 nanocomposite

This work investigates the impact of graphene oxide (GO) on the structural, morphological, optical, and photocatalytic investigations of Fe2O3, an excellent photocatalyst for industrial wastewater treatment. Using the straightforward and inexpensive sol-gel auto-combustion, hummer's method and sonication method, Fe2O3 nanoparticle (NPs), GO nanosheet, and GO-based Fe2O3 (GO/Fe2O3) nanocomposite have been synthesized, respectively. The XRD patterns, Raman spectra, and FTIR spectroscopy were used for the structural analysis, which verifies the single phase hexagonal geometry of Fe2O3 NPs. The average size of the crystallites is seen to have reduced from 50 nm to 44 nm for Fe2O3 and GO/Fe2O3. The SEM along with EDS were applied to investigate the surface morphology and confirm the existence of the elements Fe and O in pure Fe2O3, and C, Fe and O in GO/Fe2O3. From UV–vis absorbance spectra, the decrease in optical band gap (2.5 eV–1.9 eV) caused by GO incorporation has been inferred, as clearly displayed in the Tauc plots. X-ray photoelectron spectroscopy (XPS) confirms the presence of Fe2+/Fe+3 ionic states and large oxygen vacancies in the GO/Fe2O3 nanocomposite. The photocatalytic properties of both materials for the toxic MB (methylene blue) dye photodegradation in an aqueous solution was evaluated while being exposed to sunlight. It makes an excellent choice for wastewater treatment due to the high photocatalytic activity of magnetically separable GO/Fe2O3 nanocomposite for decomposing the MB dye.

Steering in-situ low-voltage phase transition from spinel to layered cathode for high-performance zinc-ion batteries

ZnV2O4, as a ternary transition metal oxides (TOMs), has garnered significant attention as a high-performance cathode for zinc-ion batteries (ZIBs) primarily due to its high theoretical capacity and abundance. However, its densely-packed lattice structure and strong coulomb interactions with the guest Zn2+ severely restrict the exposure of active sites and impede the diffusion kinetics. Herein, we propose an innovative in-situ low-voltage phase transition strategy and successfully trigger thorough phase transition of spinel-structured ZnV2O4 to layered-structured Zn3(OH)2V2O7⋅2H2O (ZnVOHNSs). In-depth mechanism analysis reveals that a thorough and efficient transition reaction necessitates meticulous control of the external driving force, reaction kinetics, and the reactant. The activated ZnVOHNSs with large lattice spacing and abundant oxygen vacancies provides an unobstructed pathway for accelerated ion diffusion and abundant exposed active sites for ions storage. Moreover, the inherent structure stability of ZnVOHNSs ensures exceptional reaction stability and reversibility during the Zn2+ intercalation/deintercalation process. Benefiting from these merits, the activated ZnVOHNSs cathode exhibits high reversible capacity and extraordinary rate capability (achieving 369 and 233 mAh g−1 at 0.1 and 20 A g−1, respectively), which exceeds most reported cathode materials in ZIBs. This work unveils the critical phase transition mechanism and offers insight into electrode design for advanced batteries.

High-Pressure Torsion for Highly-Strained and High-Entropy Photocatalysts

Nowadays, the environmental crisis caused by using fossil fuels and CO2 emissions has become a universal concern in people’s life. Photocatalysis is a promising clean technology to produce hydrogen fuel, convert harmful components such as CO2, and degrade pollutants like dyes in water. There are various strategies to improve the efficiency of photocatalysis so that it can be used instead of conventional methods; however, the low efficiency of the process has remained a big drawback. In recent years, high-pressure torsion (HPT), as a severe plastic deformation (SPD) method, has shown extremely high potential as an effective strategy to improve the activity of conventional photocatalysts and synthesize new and highly efficient photocatalysts. This method can successfully improve the activity by increasing the light absorbance, narrowing the bandgap, aligning the band structure, decreasing the electron-hole recombination, and accelerating the electron-hole separation by introducing large lattice strain, oxygen vacancies, nitrogen vacancies, high-pressure phases, heterojunctions, and high-entropy ceramics. This study reviews the recent findings on the improvement of the efficiency of photocatalysts by HPT processing and discusses the parameters that lead to these improvements.

Large scale and oxygen vacancy VO2 porous thin sheets to enable high-performance zinc ion storage.

Herein, we report the first result of large scale and oxygen vacancy VO2 porous thin sheets assembled by a 3D interconnected nanoflake array framework, which is recorded as VOd. The as-prepared VOd was characterized by various methods and Zn2+ intercalation/deintercalation and structural decomposition mechanisms were proposed based on ex situ X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS).

Highly Active and Water-Resistant Cu-Doped OMS-2 Catalysts for CO Oxidation: The Importance of the OMS-2 Synthesis Method and Cu Doping.

Porous cryptomelane-type Mn oxide (OMS-2) has an outstanding redox property, making it a highly desirable substitute for noble metal catalysts for CO oxidation, but its catalytic activity still needs to be improved, especially in the presence of water. Given the strong structure-performance correlation of OMS-2 for oxidation reactions, herein, OMS-2 is synthesized by solid state (OMS-2S), reflux (OMS-2R), and hydrothermal (OMS-2H) methods, aiming to improve its CO oxidation performance through manipulating synthesis parameters to tailor its particle size, morphology, and crystallinity. Characterization shows that OMS-2S has the highest CO oxidation activity in the absence of water due to its low crystallinity, high specific surface area, large oxygen vacancy content, and good redox property, but the presence of water can greatly reduce its CO oxidation activity. Doping Cu into an OMS-2 can not only improve its CO oxidation activity but also greatly improve its water tolerance. The Cu-doped OMS-2S catalyst with ∼4 wt % Cu can achieve a T90 of 49 °C (1% CO/10% O2/N2 and WHSV = 60,000 mL·g-1·h-1), ranking among the lowest reported T90 values for Mn oxide-based CO oxidation catalysts, and it can maintain nearly 100% CO conversion in the presence of 5 vol % water for over 50 h. In situ DRIFTs characterization indicates that the good water resistance of Cu-doped OMS-2S can be attributed to the significantly suppressed surface hydroxyl group generation because of Cu doping. This work demonstrates the importance of the synthesis method and Cu doping in determining the CO oxidation activity and water resistance of OMS-2 and will provide guidance for synthesizing highly active and water-resistant CO oxidation catalysts.

ZnO nanowire/NiO foam 3D nanostructures for high-performance ethylene glycol sensing

Ethylene glycol is widely used in industrial production but poses potential safety hazards to human life and health. Unfortunately, conventional glycol gas sensors have limitations that impede their effectiveness, such as sluggish response rates, high operational temperatures, and complex preparation procedures. A new approach has been explored to address these challenges. A ZnO nanowire/NiO foam nanostructured sensor was developed specifically for rapid ethylene glycol detection. The NiO/ZnO heterojunction-based gas sensor (NZO-6) has inherent p-type gas-sensitive characteristics. Notably, it delivers a response of 58.98–100 ppm of ethylene glycol at a relatively low operating temperature of 175 ℃. At a relatively low operating temperature of 175 ℃, it exhibits a response of 58.98–100 ppm ethylene glycol, 2.28 times higher than NiO foam, and a fast response/recovery time (4 s/26 s). This improvement is attributed to the porous structure of NiO foam/ZnO nanowires, with a large specific surface area and numerous oxygen vacancies generated during synthesis. Additionally, the catalysis of Ni metal and the formation of p/n heterojunctions further contribute to the improved sensing performance. This research offers a promising solution for developing high-performance ethylene glycol gas sensors with potential environmental monitoring, industrial safety, and public health applications. Further, this synthesis method provides an effective strategy for constructing other NiO-based heterostructure-based gas sensors.

AC Conduction Mechanism and Impedance Analysis of Conventional and Plasma‐Sintered Yttria‐Stabilized ZrO2@Mullite Composite

AbstractThe addition of 8 mol% of Y2O3 to the ZrO2@mullite composites stabilizes the metastable tetragonal phase of ZrO2 in conventional and plasma‐sintered Y2O3‐stabilized ZrO2@mullite composites. A fused, highly dense, and interconnected microstructure is formed in the case of plasma‐sintered Y2O3 stabilized ZrO2@mullite composite. At 1 MHz frequency, the room temperature and tanδ of (10.37 and 2.06) is obtained for the conventional Y2O3 stabilized ZrO2@mullite composite and that of (38.8 and 4.02) is observed for the plasma sintered Y2O3 stabilized ZrO2@mullite composite. The substitution of Y3+ in place of Zr4+ creates sufficiently large oxygen vacancies at the grain boundary regions of these composites endowed mostly with the ZrO2 phase. In conventional Y2O3‐ ZrO2@mullite composites, both dielectric relaxation as well as conductivity relaxation are observed due to the dynamic motion of dipoles and relaxation due to the presence of defect states and porous structures. This leads to higher grain boundary conductivity than the grain conductivity of these composites. Thermally activated conduction mechanisms exhibited in these composite materials are projected from the complex impedance and modulus analysis. The conventional and plasma sintered Y2O3‐ ZrO2@mullite composite has an optical bandgap of 3.26 and 3.58 eV, respectively.

Determination of uric acid in serum by SERS system based on VO-MnCo2O4/Ag nanozyme

The level of uric acid is crucial to human health. Octahedral oxygen vacancy MnCo2O4/Ag (VO-MnCo2O4/Ag) nanozyme was successfully prepared by simple hydrothermal, calcination and self-reduction methods. VO-MnCo2O4/Ag nanozyme is rich in Mn2+/Mn3+ and CO2+/CO3+ redox electron pairs, large specific surface area and oxygen vacancies. VO-MnCo2O4/Ag nanozyme showed high uricase-like activity and peroxidase-like activity. At the same time, the SERS signal of the detected molecule could be significantly enhanced after the catalytic reaction of the VO-MnCo2O4/Ag nanozyme. The Km values of VO-MnCo2O4/Ag nanozyme for H2O2 and TMB were 0.04 mM and 0.027 mM respectively. Based on the uric acid oxidase-like and peroxidase-like activities of VO-MnCo2O4/Ag, we developed a label-free, sensitive, and reliable SERS uric acid detection system. The detection linear range of uric acid is 0.01 μM–1000 μM and the detection of limit is 7.8 × 10−9 M. The results show that the sensing system has good accuracy, sensitivity, selectivity, and stability. It can be applied to the determination of samples under different conditions. This study provides profound insights into the design of enzyme-like activity regulation and SERS properties regulation of nanozymes, provides guidance for the study of reaction kinetics and catalytic mechanism of nanozymes, and has broad application prospects in the field of nanozymes and SERS sensing analysis.

Hydrogen Bonding Induced Confinement Effect between Ultrafine Nanowires and Polymer Chains for Low-Energy-Barrier Ion Transport in Composite Electrolytes.

Achieving low-energy-barrier lithium ion transport is a fundamental issue for composite solid-state electrolytes (CSEs) in all-solid-state lithium metal batteries (ASSLMBs). In this work, a hydrogen bonding induced confinement strategy was proposed to construct confined template channels for low-energy-barrier lithium ion continuous transport. Specifically, the ultrafine boehmite nanowires (BNWs) with 3.7 nm diameter were synthesized and superiorly dispersed in a polymer matrix to form a flexible CSE. The ultrafine BNWs with large specific surface areas and abundant oxygen vacancies assist the dissociation of lithium salts and confine the conformation of polymer chain segments by hydrogen bonding between the BNWs and the polymer matrix, thus forming a polymer/ultrafine nanowire intertwined structure as template channels for dissociated lithium ions continuous transport. As a result, the as-prepared electrolytes displayed a satisfactory ionic conductivity of 0.714 mS cm-1 and low energy barrier (16.30 kJ mol-1), and the assembled ASSLMB delivered excellent specific capacity retention (92.8%) after 500 cycles. This work demonstrates a promising way to design CSEs with high ionic conductivity for high-performance ASSLMBs.

Enhancements on oxygen vacancy and light absorption of alkaline-etched BiVO4 for photoelectrochemical water oxidation

Designing the favorable morphology with large surface area and abundant oxygen vacancies for BiVO4 can enhance its electron diffusion lengths and improve its photocatalytic ability toward photoelectrochemical water oxidation. The ex-situ alkaline etching process is reported to be facile for enhancing the light absorption and oxygen vacancy of BiVO4, but the systematic study of alkaline etching on the photocatalytic ability of BiVO4 is rare. In this study, alkaline-etched BiVO4 is firstly fabricated using a hydrothermal process with different durations as the photocatalyst of water oxidation. The BiVO4 etched by alkaline for longer durations presents rougher surface, more oxygen vacancies and higher light absorption. The larger carrier densities and the smaller charge-transfer resistances are also achieved for the alkaline etched BiVO4. The largest photocurrent density of 2.38 mA/cm2 is achieved at 1.23 V versus reversible hydrogen electrode in the Na2SO4 electrolyte for BiVO4 etched by alkaline for 45 min, while the pristine BiVO4 electrode only shows a photocurrent density of 0.59 mA/cm2. The photocurrent retention of 81% is also obtained for the alkaline etched BiVO4 electrode after continuous illumination for 6000 s. The results imply the feasibility of applying the alkaline etching process on refining the photoelectrochemical catalytic ability of BiVO4.

Boosting Oxygen Reduction Activity of Co3O4 through a Synergy of Ni Doping and Carbon Species Dotting for Zn-air Battery

Oxygen reduction reaction (ORR) undertakes an indispensable driving role for metal-air batteries with sluggish kinetics. In this work, we proposed a synergic strategy of Ni doping and carbon species dotting to compose Co3O4 with intrinsic large specific area and oxygen vacancies. The Ni-doped Co3O4/C (NCC-1) with four electron transfer mode conducts extraordinary electrocatalytic performance than commercial 20 wt% Pt/C and excellent tolerance to methanol poisoning. This series of improvements are attributed to the rapid dynamics drove by variable transition metal valence with elevated electronic conductivity derived from dotted carbon species. The XPS results at different reduction stages investigate that the doped Co3O4/C affects ORR performance by adjusting the species of *O at the active sites and the formation of intermediates including *OH and *O. More Co3+ active sites exposed on the NCC-1 surface, higher catalytic activity is provided by the conversion of Co(Ⅱ)/Co(III) and Ni(Ⅱ)/Ni(III). What is purposeful in practicability. the NCC-1/IrO2 based Zn-air batteries show an excellent charge-discharge response and cyclability than that of 20% Pt/IrO2 based Zn-air batteries, highlighting the implemented potentiality of NCC-1 based metal-air-battery. This study offers new insights into designing non-noble-metal based oxygen reduction electrocatalysts for more energy storage devices.

Facile synthesis of anatase TiO2 nanoparticles using titanium metal and its enhanced photocatalytic activity under visible light

A green sol-gel method was employed to synthesize TiO2 nanoparticles (NPs) using titanium metal. The syn-thesized TiO2 NPs underwent comprehensive characterization using techniques including X-ray diffraction (XRD), infrared spectroscopy (IR), transmission electron microscopy (TEM), and UV–Vis diffuse reflectance spectroscopy (UV-Vis DRS) to evaluate their structure, morphology, and spectral properties. By adjusting the amount of oxalic acid, tailored physico-chemical properties of anatase TiO2 catalysts were achieved. The obtained TiO2 catalysts demonstrated a high surface area, excellent absorption, and remarkable photocatalytic degradation of methylene blue under visible light irradiation. This enhancement is primarily contributed by the large surface area and oxygen vacancies.

Facile Fabrication of ZnO Nanoparticles for efficient dye degradation: Effect of Adipic Acid in photocatalytic activity

AbstractPhotocatalysis is the most environmentally benign and efficient method for degrading organic dyes in water purification. Herein, the synthesis of ZnO nanoparticles was achieved by simple homogeneous chemical precipitation via the support of adipic acid and followed the calcination process at elevated temperatures. Based on the physical and morphological characterization analysis, the high crystallinity hexagonal structure with uniform granular shape morphology of the ZnO nanoparticles was formed with a band gap of 3.2 eV. The photocatalytic performance of the ZnO nanoparticles was investigated with the degradation of methylene blue (M.B.) dye as a model compound in an aqueous medium under UV light irradiation. The optimal ZnO‐700 nanoparticles demonstrated the highest photocatalytic activity thanks to their large surface area and numerous oxygen vacancies. More importantly, a small amount of photocatalyst (0.4 g/L) successfully degraded M.B. dye from an aqueous solution with 100 % efficiency within just 11 minutes of irradiation time under UV light with protective photocatalytic activity 4 sequential cycles. Besides, in‐depth photocatalysis experiments present that via a facile two‐step synthesis method, the as‐prepared ZnO photocatalysts depict enhanced chemical stability in a harsh environment and efficient photodegradation.