ZnO NSs Research Articles

An Innovative Biphasic Reaction System for Highly Selective Benzene Hydroxylation based on Photocatalytic Polymer Composites

AbstractThe hydroxylation of benzene to phenol in presence of hydrogen peroxide was performed using a new biphasic system consisting of a solid phase, a photocatalytically active monolithic polymer composite, immersed in an aqueous phase in which H2O2 is dissolved. In detail, ZnO photocatalytic particles were embedded into the hydrophobic syndiotactic polystyrene (sPS) polymer. Zinc oxide nanostructures (ZnO NSs) were synthesized by an electrochemical procedure. The surface morphology and structure of ZnO nanoparticles and ZnO‐sPS monolithic aerogel composite (ZnO/sPS) were investigated by scanning electron microscopy, X‐ray diffraction and X‐ray photoelectron spectroscopy analysis. Photocatalytic results evidenced that, under UV irradiation, both ZnO NSs and biphasic system water‐photocatalytic composites had a high benzene oxidative property but with very low phenol yield (<2 %) at pH=7. To enhance the phenol selective formation, the pH of the aqueous solution surrounding the photocatalytic polymer composite was modified. A phenol yield of about 94 % and benzene conversion higher than 99 % was obtained in alkaline conditions (pH=11).

Electrospun zinc oxide nanoscaffolds: a targeted and selective anticancer approach

This study aims to prepare, characterize, and evaluate zinc oxide nanoscaffolds (ZnO NSs) as a potential anticancer drug that selectively targets malignant cells while remaining non-toxic to normal cells. Electrospun NSs were fabricated and loaded with varying concentrations of ZnO nanoparticles (NPs). The uniform morphology of the fabricated samples was confirmed through Field Emission Scanning Electron Microscope (FESEM) imaging. Elemental composition was investigated using Energy Dispersive X-ray spectroscopy (EDX), Fourier Transform Infrared (FTIR), and X-ray diffraction (XRD) analyses. Biocompatibility and cytotoxicity were assessed using the (3-(4.5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay) (MTT) assay and flow cytometry. The water uptake and degradation properties of the electrospun NSs were also examined. Furthermore, a cumulative release profile was generated to assess the release behavior of ZnO NSs. The prepared ZnO NSs demonstrated negligible toxicity toward normal human dermal cells. Conversely, the four used concentrations of ZnO NSs displayed substantial cytotoxicity and induced apoptosis in various cancer cell lines. The observed effects were concentration-dependent. Notably, ZnO NSs 8% exhibited the most significant reduction in cell viability against the MCF7 cell line. The findings from this study indicate the potential of ZnO NSs as an effective anticancer agent, with the ZnO NSs 8% demonstrating the most pronounced impact. This research introduces a novel application of electrospun zinc oxide nanoscaffolds, demonstrating their capacity for selective anticancer activity, particularly against breast carcinoma, while preserving normal cell viability. The study presents a significant advancement in the use of nanomaterial for targeted cancer therapy.

Photocatalytic degradation of antibiotics and antimicrobial and anticancer activities of two-dimensional ZnO nanosheets

Active pharmaceutical ingredients have emerged as an environmentally undesirable element because of their widespread exploitation and consequent pollution, which has deleterious effects on living things. In the pursuit of sustainable environmental remediation, biomedical applications, and energy production, there has been a significant focus on two-dimensional materials (2D materials) owing to their unique electrical, optical, and structural properties. Herein, we have synthesized 2D zinc oxide nanosheets (ZnO NSs) using a facile and practicable hydrothermal method and characterized them thoroughly using spectroscopic and microscopic techniques. The 2D nanosheets are used as an efficient photocatalyst for antibiotic (herein, end-user ciprofloxacin (CIP) was used as a model antibiotic) degradation under sunlight. It is observed that ZnO NSs photodegrade ~ 90% of CIP within two hours of sunlight illumination. The molecular mechanism of CIP degradation is proposed based on ex-situ IR analysis. Moreover, the 2D ZNO NSs are used as an antimicrobial agent and exhibit antibacterial qualities against a range of bacterial species, including Escherichia coli, Staphylococcus aureus, and MIC of the bacteria are found to be 5 μg/l and 10 μg/l, respectively. Despite having the biocompatible nature of ZnO, as-synthesized nanosheets have also shown cytotoxicity against two types of cancer cells, i.e. A549 and A375. Thus, ZnO nanosheets showed a nontoxic nature, which can be exploited as promising alternatives in different biomedical applications.

Synthesis and Antimicrobial Applications of ZnO Nanostructures: A Review

ZnO nanostructures (ZnO NSs) are able to provide significant antimicrobial activity, ensuring high biocompatibility, good chemical stability, and low toxicity. Such versatility has led to great success of this nanomaterial for antibacterial, antifungal, and, more recently, antiviral applications. However, methods for the preparation of ZnO NSs must be properly selected for their end use. Moreover, ZnO NSs can also be cytotoxic to some extent. In this context, this review emphasizes some aspects relevant to the preparation as well as to the antimicrobial use of ZnO NSs. In particular, a brief overview of the sol–gel, hydrothermal, biogenic, and electrochemical approaches proposed for their synthesis is presented, highlighting advantages/drawbacks of each route in terms of scalability, simplicity, and efficacy. Next, the application of ZnO NSs in several fields is reported. This is followed by a discussion of the antimicrobial role of ZnO NSs, where antimicrobial mechanisms of action, possible cell resistance, and cytotoxicity of ZnO NSs are highlighted. We also discuss the role of ZnO NSs against different biothreats, such as bacteria and viruses. The future of such nanomaterials in this application field is addressed in the final part.

New Radical Route and Insight for the Highly Efficient Synthesis of Benzimidazoles Integrated with Hydrogen Evolution

AbstractBenzimidazoles are a versatile class of scaffolds with important biological activities, whereas their synthesis in a lower‐cost and more efficient manner remains a challenge. Here, we demonstrate a conceptually new radical route for the high‐performance photoredox coupling of alcohols and diamines to synthesize benzimidazoles along with stoichiometric hydrogen (H2) over Pd‐decorated ultrathin ZnO nanosheets (Pd/ZnO NSs). The mechanistic study reveals the unique advantage of ZnO NSs over other supports and particularly that the features of Pd nanoparticles in facilitating the cleavage of the α‐C−H bond of alcohols and adsorbing subsequently‐generated C‐centered radicals hold the key to turning on the reaction. This work highlights a new insight into radical‐induced efficient benzimidazole synthesis pairing with H2 evolution by rationally designing semiconductor‐based photoredox systems.

New Radical Route and Insight for the Highly Efficient Synthesis of Benzimidazoles Integrated with Hydrogen Evolution.

Benzimidazoles are a versatile class of scaffolds with important biological activities, whereas their synthesis in a lower-cost and more efficient manner remains a challenge. Here, we demonstrate a conceptually new radical route for the high-performance photoredox coupling of alcohols and diamines to synthesize benzimidazoles along with stoichiometric hydrogen (H2 ) over Pd-decorated ultrathin ZnO nanosheets (Pd/ZnO NSs). The mechanistic study reveals the unique advantage of ZnO NSs over other supports and particularly that the features of Pd nanoparticles in facilitating the cleavage of the α-C-H bond of alcohols and adsorbing subsequently-generated C-centered radicals hold the key to turning on the reaction. This work highlights a new insight into radical-induced efficient benzimidazole synthesis pairing with H2 evolution by rationally designing semiconductor-based photoredox systems.

A synergistic effect between ZnO/CdS S-scheme heterojunction and GO cocatalyst for boosting photocatalytic performance

ZnO nanosheets, 2D/1D ZnO/CdS hybrid and ternary ZnO/CdS/GO S-scheme heterojunction photocatalyst were fabricated by a low-temperature hydrothermal technique. As expected, by investigating the degradation efficiency of rhodamine B under simulated sunlight, with the assistance of CdS and GO, the ternary heterostructure showed superior photocatalytic activity. The test results display that the dye degradation rate constant of ZnO/CdS/GO is about 1.75 × 10−2 min−1, which is 3.6 times higher than that of bare ZnO. SEM results prove the finding that the content of CdS can regulate the size and distribution of ZnO NSs, increasing the specific surface area of the sample. Besides, the results of ultraviolet–visible (UV–vis) absorbance spectra revealed that the addition of CdS and GO significantly synergistically increased the visible light absorption of ZnO, and also shortened the band gap of ZnO. Photoluminescence (PL) spectra, electrochemical impedance spectroscopy (EIS) and transient photocurrent response (TPR) results show that the presence of CdS and GO synergistically promotes the rapid separation of photoexcited carriers in ZnO. Notably, the GO also further speeds up the transmission rate of electrons and improves the photoelectric stability of the ZnO/CdS heterogeneous photocatalyst. The above changes can effectively promote the photocatalytic performance of photocatalysts. Moreover, a reasonable S-scheme carriers migration mechanism was proposed with the assistance of Mott-Schottky (MS) test, VB-XPS and sacrificial agent experiments. Through comprehensive analysis and discussion, it can be concluded that ZnO/CdS S-scheme heterojunction and GO synergistically promote the photocatalytic performance of ZnO. Therefore, this thesis may provide a deeper insight into developing the practical application of ZnO-based heterojunction photocatalysts in pollutant degradation.

Conductometric sensor for gaseous sulfur-mustard simulant by gold nanoparticles anchored on ZnO nanosheets prepared via microwave irradiation

We report the microwave-assisted synthesis of Au nanoparticles (NPs) anchored porous ZnO nanosheets (Au-ZnO NSs) and their application in the sensitive detection of 2-chloroethyl ethyl sulfide (2-CEES) vapors, which are a simulant of sulfur mustard chemical weapon. Upon microwave irradiation for < 1 min with an annealing, highly crystalline Au NPs with a narrow particle-size distribution (2.32 ± 0.40 nm) are densely formed on the surface of porous ZnO NSs, which increases the density of oxygen vacancies in the ZnO. Under the optimal working temperature (450 °C), the response of the Au-ZnO NS sensor was measured to be 787 for 10 ppm 2-CEES, which is ∼14 times higher than that observed for the bare porous ZnO NSs-based sensor. Moreover, Au-ZnO NSs can detect 2-CEES gas even under high humidity (∼80 %) benefiting from its high sensitivity. The highly reproducible sensing performance was verified by repeated sensing test (20 times for 12 h). According to gas screening data, the Au-ZnO NSs exhibited outstanding selectivity toward sulfide compounds due to the high Au-S affinity. In summary, we have successfully demonstrated a simple and facile approach to form the Au-ZnO heterostructure by microwave irradiation and enhanced the gas-sensing performance by inducing catalytic activity.

Design and characteristics of two-dimensional piezoelectric nanogenerators

Abstract In the last decades, increasing interest in piezoelectric material has opened new horizons in electronic industries and alternative energy fields. In this study, a piezoelectric (ZnO NSs–Na2Ti6O13) were prepared from Zinc Oxid Nanosheets (ZnO NSs) and Disodium Hexa titanate (NTO). The dielectric, harvester performance, and the pyroelectric effect of ZnO NSs – NTO explored experimentally. Under different experimental conditions and mechanisms, the generated voltages had been measured where a quasi-static pressing force was applied at the harvester. In addition, the derived voltage has been rectified when the harvester was mounted over a cantilever beam, where the power density was 0.10 ± 0.1 mW/cm3. Finally, there was further investigation of the pyroelectric property which yielded a maximum pyroelectric coefficient of 30.51 µC/m2 °C at low temperature.

A highly efficient acetone gas sensor based on 2D porous ZnFe2O4 nanosheets

In this study, 2D porous ZnFe2O4 nanosheets (ZnFe2O4 NSs) were fabricated for use as sensing materials using a 3-stage process involving soaking, freeze-drying, and calcination steps. The ZnFe2O4 NS-based sensor produced exhibited satisfactory sensing performance and selectively for acetone and achieved a response value of 64.9 at 50 ppm and response/recovery times of 23 and 9 s at operating temperature, which was far better than the performances of ZnO NSs and Fe2O3 NSs (controls) produced using the same method. The excellent sensing properties of ZnFe2O4 NSs were attributed to greater porosity, larger pore sizes, and higher proportions of oxygen-deficient and chemisorbed oxygen species. The study shows that the ZnFe2O4 NS-based sensing material produced for the detection of VOCs, especially acetone, shows considerable promise.

Annealing temperature effect on the performances of porous ZnO nanosheet-based self-powered UV photodetectors.

Porous ZnO nanosheets (ZnO NSs) may play an important role in self-powered UV photodetectors due to their excellent properties, and their porosity feature affects the photoresponse performance greatly. Porous ZnO NSs were prepared by the hydrothermal method followed with a one-step annealing treatment. The effects of the annealing temperature on the microstructure and photoresponse of porous ZnO NSs and n-ZnO NSs/p-PEDOT:PSS self-powered UV photodetectors were investigated. The results show that the pore density and size of ZnO NSs can be tuned by changing the annealing temperature. At an optimum annealing temperature of 450°C, ZnO NSs exhibit greater absorption capacity for the suitable pore density and size. Meanwhile, more crystal defects due to surface contractile properties increase the number of photogenerated carriers. On this basis, the n-ZnO NSs/p-PEDOT:PSS photodetector presents a larger photocurrent and fast photodetection speed without external bias voltage, indicating the self-powered performance. The higher light absorption and large number of electron-hole pairs resulting from dense pores and surface defects in porous ZnO NSs might account for the enhanced performances.

Fluorometric biosensor based on boronic acid-functionalized ZnO-derived nanostructures for the detection of N-acetylneuraminic acid and its in vivo bio-imaging studies

BackgroundN-acetylneuraminic acid (Neu5Ac) is a sialic acid-based biomarker in neurological disorders like Alzheimer's disease (AD) and aging. Their abnormal concentrations in biological fluids like human serum and cerebrospinal fluid (CSF) are highly concerning. Conventional analytical methods lack time-saving, high sensitivity, and convenient labor options for their detection. In this study, a selectively recognizable fluorometric sensor was developed based on the boronic acid-functionalization of carbon-rich zinc oxide-derived nanostructures (ZnO NSs) for Neu5Ac detection. MethodsThe ZnO NSs were synthesized using the acid-alkali-assisted hydrothermal method from anionic surfactants like sodium dodecyl sulfate (SDS). These were functionalized with 3-(aminopropyl)-triethoxysilane (APTES): (APT-ZnO NSs), aspirin [acetylsalicylic acid (ASA)]: (ASA-APT-ZnO NSs), and quercetin: (Qu-ASA-APT-ZnO NSs). To enhance the detection capacity against Neu5Ac, Qu-ASA-APT-ZnO NSs were modified with 3-aminophenylboronic acid (APBA) (APBA-ZnO NSs). Their structural, functional, and optical performance were investigated using XRD and Raman, FT-IR, and UV-Vis spectroscopy. Significant findingsFlower-like ZnO NSs showed a typical ZnO plane (110) of wurtzite hexagonal crystalline phase under HRTEM analysis. The novelty of the proposed work is the development of highly sensitive and efficient APBA-ZnO NSs for Neu5Ac detection in the linear concentration range of 0 to 8 µM with a low detection limit of 0.56 µM. These results are comparable to the other reports, and their multicolor fluorescence properties in zebrafish larvae confirm them as magnificent fluorescent probes for in vivo bio-imaging studies. The practicality of the proposed APBA-ZnO NSs was explored in serum and CSF samples, which showed potential recovery percentage ranges of 97–104.66% and 96.33–105.37%, respectively. In the future, these fluorescent probes will have the appropriate scope for the in vitro and in vivo detection of diverse neurological biomarkers.

Effect of hydrogen-related shallow donor on the physical and chemical properties of Ag-doped ZnO nanostructures

Silver-doped zinc oxide nanostructures (Ag/ZnO NSs) with Ag content of 0 wt%, 5 wt%, 10 wt%, and 20 wt% were synthesized using a hydrothermal technique. The prepared nanostructures were annealed at 500 °C for 2 h. The samples were characterized by using scanning electron microscopy, FTIR, X-ray diffraction (XRD), and electrical conductivity. FTIR spectra confirms the presence of hydrogen-related shallow donor defects in the Ag/ZnO NSs, which bind to the oxygen vacancy ({text{H}}_{text{O}}) and consequently plays a significant role in the physicochemical properties of the metal oxide nanostructures. The {text{H}}_{text{O}} defects are blended to O- and Zn-polar Ag-doped ZnO NSs, depending on their polarity. XRD results verified that Ag/ZnO NSs have a polycrystalline hexagonal structure. Williamson–Hall methods were used to estimate the microstructural properties of polycrystalline nanostructures. The electrical conductivity increased from 0.60 to 1.10 µS/cm, and the bandgap energy decreased from 3.36 to 3.10 eV by increasing the Ag from 0 wt% up to 20 wt%.

Comprehensive Study on Indian Plant Extracts Mediated Biocompatible ZnO Nanostructures: A Green Initiative

Zinc oxide nanostructures of variable morphology are extensively used in diversified applications of biomedical sector like antibacterial, anticancer, antifungal and targeted drug delivery utilizations. However, their biocompatibility and cytotoxicity are major issues restricting their commercial development for biomedical applications. Green chemistry is a game touting strategy to fabricate biocompatible zinc oxide nanoparticles for diversified biomedical applications. It eliminates the various bottlenecks associated with physical (high power consumption) and chemical (environmental contamination) fabrication strategies utilized for nanomaterial synthesis.Green strategies majorly use biomass and related materials such as plant extract, essential oils or bacteria, as bio reducing, capping and stabilizing agents for facile fabrication of metal based nanoparticles. It turns these techniques into economic, simpler, eco friendly, non-toxic and less contaminating strategies with high scope of scalable optimization and production. Indian herbs and plants like Mangifera indica, Coriander sativum, Aloe vera are being traditionally used as medicinal remedies and possess high antimicrobial efficacies. The extracts from different parts of these plants like leaves, roots, stem or flower (essential oil) are proven for their bio reducing and stabilizing capabilities in nanomaterial fabrication. This review, for the first time, focuses on the usage of several India-based plants for green production of zinc oxide nanostructures with diverse morphologies and physicochemical properties. The present study covers many parameters affecting the morphologies of plant-mediated ZnO NSs and their benefits over traditional approaches. Besides associated challenges, alternate solutions and prospects are able to attain the United Nations sustainable development goal for environmental sustainability, good health and well being.

Interfacial modification and tribological properties of ZnO nanosheet carbon fiber reinforced poly(hexahydrotriazine) composites

The weak bonding strength between the non-polar carbon fiber (CF) surface and the polymer presents a challenge for the extended friction application of CF reinforced polymer composites. Here, we present a simple electroplating and oxidation method to introduce two-dimensional ZnO nanosheets (ZnO NSs) between CF and poly(hexahydrotriazine)s (PHTs). ZnO NSs form strong C-O-Zn chemical bond with CFC and create micro-nano convex surface, which enhance the shear strength of the interface and exert a toughening effect in CFRPs. The resultant PHT/ZnO@CFC showed excellent tribological properties, the coefficient of dry friction reduced by 57%, which showed that grafting ZnO NSs significantly improved tribological applications of recyclable CFRPs, demonstrating the potential incorporation of PHTs in the field of wear resistance.

High-performance flexible surface-enhanced Raman scattering substrate based on the particle-in-multiscale 3D structure

Abstract Recently, multiscale three-dimensional (3D) structures consisting of micrometer-scale structure and nanometer-scale structure have received some attention from scientists in the field of surface-enhanced Raman scattering (SERS). In this work, micrometer-scale grating structure and nanometer-scale zinc oxide nano spikes (ZnO NSs) structure are successfully introduced into the SERS substrate with silver nanoparticles (Ag NPs) as the surface plasmon. The optimized particle-in-multiscale 3D substrate (PDMS/grating/ZnO NSs/Ag NPs) presents high sensitivity with an ultralow limit of detection of 1 × 10−11 M and a high enhancement factor of 7.0 × 108 for Rhodamine 6G (R6G) as the probe molecule. It benefits from the electromagnetic field enhancement from the excellent optical capture capability of grating/ZnO NSs structure and abundant electromagnetic hot spots. The quantitative analysis ability of the SERS substrate can be indicated from the good linear correlation between the logarithmic Raman intensity and the molecular concentration. At the same time, this SERS substrate exhibits excellent homogeneity and reproducibility, which have low relative standard deviations (4.43%) of the Raman intensities at 613 cm−1 peaks for R6G as the probe molecule. In addition, this SERS substrate can realize in-situ detection of Raman signal due to its excellent light transmission and flexibility. The particle-in-multiscale 3D structure as SERS substrate exhibits the vast potential in practical applicability for qualitatively and quantitatively chemical and biomedical analysis.

Variation of Alkali Concentration and Temperature: Its Effect on the Morphology of ZnO Nanoparticles Synthesized via Solvothermal Technique

This study reports on synthesis of ZnO nanostructures using Zinc chloride (ZnCl2) as precursors and Potassium hydroxide (KOH) as alkaline source in a solvothermal process with varying molar concentrations (Zn2+/OH-) of 1:1, 1:3 and 1:5 for temperatures of 30 °C and 50 °C. The synthesized nanostructures were characterized by X-Ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FE-SEM), Transmission Electron Microscopy (TEM), Fourier Transform Infrared (FT-IR) Spectroscopy, and Ultraviolet Visible (UV-Vis) spectroscopy. ZnO nanostructures synthesized at lower ratios (1:1) exhibited wurtzite hexagonal shapes. However, as the concentration ratios increases in both cases, spherical structures were formed with the emergence of some rod-like structures dominating, and finally aggregated to form flower-like structures at 30 °C temperature. The average crystallite size for nanostructures from XRD (30-50 °C) were in the range 15-21 nm whereas the average particle size from TEM analysis (30-50 °C) were in the range 39-76 nm. Increase in temperature and molar concentration of the alkaline source generally decreased the crystallite and particle size of the as well as a decrease in the wavelength of ZnO nanostructures as a result of blue-shifting of the absorption peak. FT-IR spectra of ZnO NSs prepared from concentration ratios of Zn2+: OH- (1:1, 1:3 and 1:5) at 30 °C and 50 °C showed characteristic peak bands at 461-467 cm-1 and 460-462 cm-1 respectively.

Microplasma-assisted electrochemical synthesis of ZnO nanostructures for photocatalytic and antibacterial applications

Zinc oxide nanostructures (ZnO NSs) have been extensively studied because of their many applications in different fields. In this study, an attempt has effectively been made for the synthesis of ZnO nanostructures by using fast and environment-friendly microplasma electrochemical technique. The prepared nanostructures were examined in terms of their morphological, optical, structural, electrical, and compositional properties by using different characterization techniques. Results demonstrated that the highly crystalline ZnO nanostructures were produced with a single hexagonal (wurtzite structure) phase. Results also indicated the crystallite size increases with increasing precursor concentration. The optical band gap of ZnO is found to decrease (from 3.48eV to 3.40 eV) with increasing crystallite size. I-V characteristics of ZnO are measured by two probe technique which shows semiconducting behavior of prepared ZnO. The antibacterial and photocatalytic properties of the synthesized nanostructures were also investigated. It was observed that the degradation efficiency of zinc oxide photocatalyst increases with the irradiation time. About 85% of Rhd B dye was degraded by ZnO after 120 min at a rate of 0.01339 min−1 under direct sunlight irradiation. The antibacterial activity of ZnO was carried out against different gram-positive and gram-negative bacterial strains, by using the diffusion well method. Higher antibacterial activities were observed against gram-negative bacteria as well as for a higher concentration of ZnO. This study will be helpful to synthesize low-cost and effective materials to remove microorganisms and toxic industrial organic dyes which is a serious threat to terrestrial and aquatic life.

Rationally embedded zinc oxide nanospheres serving as electron transport channels in bismuth vanadate/zinc oxide heterostructures for improved photoelectrochemical efficiency

In this work, we demonstrate the fabrication of Mo, W co-doped BiVO4/ZnO nanosphere (Mo, W: BVO/ZnO NS) heterostructures using a simple solution dry-out method that uniformly embeds ZnO NSs in Mo, W: BVO nanocrystals. Photoelectrochemical (PEC) examination confirmed that Mo, W: BVO/ZnO NSs exhibit higher PEC performance than pure Mo, W: BVO, and this improved performance of Mo, W: BVO/ZnO NSs also depends on decreased ZnO NS size. Moreover, a layered ZnO/Mo, W: BVO (ZnO film coated with Mo, W: BVO layer) heterostructure was prepared using a simple physical piled method that exhibited far lower PEC performances than those of Mo, W: BVO/ZnO NS heterostructures. These results clearly revealed that the formation of the Mo, W: BVO/ZnO NS heterostructure could increase the charge carrier density and it possessed a much larger contact area. These improvements were favorable for the transfer and transport of photoexcited charge carriers. This work offers an effective strategy to fabricate heterostructures with effective charge separation by a simple solution dry-out method that is suitable for other heterostructure-engineered photoanodes in solar water-splitting applications.

Hydrothermally grown ZnO NSs on Bi-Directional woven carbon fiber and effect of synthesis parameters on morphology

ZnO nanostructures on woven carbon fiber have been developed by hydrothermal technique under varying conditions of the process parameters. The impact of process parameters such as pH and molar concentration of precursor solution, growth duration and growth temperature on morphology and dimensions of ZnO nanostructures has been analyzed by Field Emission Gun-Scanning Electron Microscope, Energy Dispersive Spectroscopy (EDS) and UV-VIS-NIR spectroscopy. Different ZnO nanostructures of nanopallets-like, nanoflowers-like and nanoflakes-like were achieved at pH > 7 but nanorods-like and nanowires-like morphology were achieved at low pH. In addition, the impact of the chemical reactions, seeding and the growth process on ZnO nanostructures on woven carbon fibers has been discussed in the present work.