Preparation of flower-like ZnO architectures assembled with nanosheets for enhanced photocatalytic activity

Unlocking the Potential of Nanostructured ZnO on PPC Membranes: High-Throughput Synthesis, Morphology Tailoring, and Enhanced Antibacterial Activity

The development of nanostructured ZnO (nano-ZnO) with tailored morphologies is critical for creating effective antibacterial materials. This study introduces a high-throughput platform for the in situ synthesis of PPC/nano-ZnO composites, enabling precise control over the morphology of nano-ZnO to optimize antibacterial performance. By leveraging electrospinning, heat treatment, and hydrothermal synthesis, we fabricated diverse nano-ZnO structures, including nanoparticles, nanorods, and nanoflowers, on PPC nanofiber membranes. The large experimental data set generated through high-throughput synthesis facilitated the creation of a phase diagram that correlates key synthetic parameters, such as Zn2+ concentration, heat treatment temperature, and hydrothermal conditions, with nano-ZnO morphology and antibacterial efficacy. Tailoring the morphology of nano-ZnO is essential for maximizing antibacterial activity, and our results demonstrate that nanorods exhibit the highest efficacy against Escherichia coli due to their enhanced surface area and physical penetration capabilities. Phase diagram analysis revealed that increased Zn precursor concentrations promoted the growth of rod- and flower-like structures, which were linked to superior antibacterial performance. The sample with the highest antibacterial efficacy showed a maximum inhibition zone of 17.88 mm. A mechanistic model suggests that the mechanical disruption of bacterial membranes by sharp nano-ZnO structures is a key contributor to antibacterial action. This work underscores the significance of morphology control in designing effective antibacterial nanomaterials and provides a systematic approach to optimizing their properties.

Clew-like Cu2O/CuO Microsphere Adsorbents for Highly Efficient Anionic Dye Removal

Adsorbents with high selectivity and adsorption capacity are of significant interest for the removal of dye pollutants. Herein, we report a facile low-temperature solvothermal synthesis of clew-like Cu2O/CuO microspheres by using cupric acetate monohydrate as the copper resource and ethylene glycol as the solvent and morphology modulator. The synthesized Cu2O/CuO microspheres showed high selective adsorption to anionic dyes (e.g., methyl orange (MO) and Reactive Red 2 (RR2)) rather than to cationic dyes (e.g., methylene blue (MB), Rhodamine B (RhB)). MO was then selected to evaluate the parameters of adsorption due to the adsorbent exhibiting the highest adsorption capacity for MO. We demonstrate that the adsorption of MO by Cu2O/CuO microspheres has a good correlation with the pseudo-second-order model and Langmuir isotherm with a maximum adsorption capacity of 826.45 mg/g, which is higher than that of previously reported metal oxide material adsorbents. The excellent adsorption ability of clew-like Cu2O/CuO microspheres to MO may be attributed to the synergistic effects of electrostatic attraction, unique hierarchical structure, and crystal defects of the prepared Cu2O/CuO microspheres. We believe our work provides new insight into the synthesis of high-performance adsorbents.

Evaluation of ferroptosis-based anti-leukemic activities of ZnO nanoparticles synthesized by a green route against Pre-B acute lymphoblastic leukemia cells (Nalm-6 and REH)

Background

Our research presents an efficient and practical method for producing Zinc Oxide nanoparticles (ZnO NPs), which have anti-leukemic effects based on ferroptosis.

Methods

The black cardamom extract was employed as a capping and reducing agent for the green synthesis. The NPs have been characterized via scanning electron microscopy, X-ray diffraction, and Fourier-transform infrared spectroscopy. Additionally, leukemic and normal cells were exposed to ZnO NPs (25, 50, 75, 100, 150, 200, and 300 μg/mL) for 24 and 48 h. The cell vitality was then measured using the MTT test. Moreover, ferroptosis indicators were assessed via commercial testing kits, and finally, qRT-PCR and flow cytometry were used to measure gene expression and cell death.

Results

The findings displayed that green synthesized ZnO NPs reduced the survival of leukemic cells, with IC50 values of 150.89 μg/ml for Nalm-6 and 101.31 μg/ml for REH cells after 48 h. The ZnO NPs increased ferroptosis by significantly increasing MDA, intracellular iron, ACSL4, ALOX15, and p53 mRNA expressions while significantly decreasing GSH and GPx activity levels and SLC7A11 and GPx4 mRNA expressions. On the other hand, ZnO NPs exhibited no toxicity toward normal cells.

Conclusions

The research suggests that ZnO NPs synthesized using the green approach can induce ferroptosis in leukemic cells by disrupting redox homeostasis and increasing intracellular iron levels, potentially enhancing the benefits of anti-leukemic therapies in the future.

Assessment of Performance of Photocatalytic Nanostructured Materials with Varied Morphology Based on Reaction Conditions

Synthesis of nanomaterials with specific morphology is an essential aspect for the optimisation of its properties and applications. The application of nanomaterials is being discussed in a wide range of areas, one of which is directly relevant to the environment through photocatalysis. To produce an effective photocatalyst for environmental applications, morphology plays an important role as it affects the surface area, interfaces, crystal facets and active sites, which ultimately affects efficiency. The method of synthesis and synthesis temperature can be the basic considerations for the evaluation of a particular nanomaterial. In this study, we have considered the aspects of morphology with a basic understanding and analyzed them in terms of nanomaterial efficacy in photocatalysis. Different morphologies of specific nanomaterials such as titanium dioxide, zinc oxide, silver phosphate, cadmium sulphide and zinc titanate have been discussed to come to reasonable conclusions. Morphologies such as nanorods, nanoflower, nanospindles, nanosheets, nanospheres and nanoparticles were compared within and outside the domain of given nanomaterials. The different synthesis strategies adopted for a specific morphology have been compared with the photocatalytic performance. It has been observed that nanomaterials with similar band gaps show different performances, which can be linked with the reaction conditions and their nanomorphology as well. Materials with similar morphological structures show different photocatalytic performances. TiO₂ nanorods appear to have the best features of efficient photocatalyst, while the nanoflowers show very low efficiency. For CdS, the nanoflower is the best morphology for photocatalysis. It appears that high surface area is the key apart from the morphology, which controls the efficiency. The overall understanding by analyzing all the available information has enumerated a path to select an effective photocatalyst amongst the several nanomaterials available. Such an analysis and comparison is unique and has provided a handle to select the effective morphology of nanomaterials for photocatalytic applications.

Efficient Removal of Methylene Blue and Ciprofloxacin from Aqueous Solution Using Flower-like, Nanostructured ZnO Coating under UV Irradiation

Flower-like ZnO architectures assembled with many nanorods were successfully synthesized through Thermionic Vacuum Arc, operated both in direct current (DC-TVA) and a pulsed mode (PTVA), and coupled with annealing in an oxygen atmosphere. The prepared coatings were analysed by scanning-electron microscopy with energy-dispersive X-ray-spectroscopy (SEM-EDX), X-ray-diffraction (XRD), and photoluminescence (PL) measurements. By simply modifying the TVA operation mode, the morphology and uniformity of ZnO nanorods can be tuned. The photocatalytic performance of synthesized nanostructured ZnO coatings was measured by the degradation of methylene-blue (MB) dye and ciprofloxacin (Cipro) antibiotic. The ZnO (PTVA) showed enhancing results regarding the photodegradation of target contaminants. About 96% of MB molecules were removed within 60 min of UV irradiation, with a rate constant of 0.058 min−1, which is almost nine times higher than the value of ZnO (DC-TVA). As well, ZnO (PTVA) presented superior photocatalytic activity towards the decomposition of Cipro, after 240 min of irradiation, yielding 96% degradation efficiency. Moreover, the agar-well diffusion assay performance against both Gram-positive and Gram-negative bacteria confirms the degradation of antibiotic molecules by the UV/ZnO (PTVA) approach, without the formation of secondary hazardous products during the photocatalysis process. Repeated cyclic usage of coatings revealed excellent reusability and operational stability.

Strategies to Enhance ZnO Photocatalyst's Performance for Water Treatment: A Comprehensive Review

Despite the photocatalytic organic pollutant degradation using ZnO started in 1910-1911, many challenges are still ahead, and several critical issues have to be addressed. Large band gap, and short life-time of photogenerated electrons and holes are critical issues negatively affect the photocatalytic activity of ZnO. Various approaches have been introduced to overcome these issues including intrinsic doping, extrinsic doping, and heterostructure. This review introduces unique and deep insights into tuning of the photocatalytic activity of ZnO. It starts by description of how to tune the photocatalytic activity of pristine ZnO through tuning its morphology, surface area, exposed face, and intrinsic defects. Afterward, the review explains how the Z-scheme approach succeed to address the redox weakened issue of heterojunction approach. In general, this review provides a clear image that helps the researcher to tune the photocatalytic activity of pristine ZnO and its heterostructure.

Enhanced photocatalytic performance of ZnO/AgCl composites prepared by high-energy mechanical ball milling

ZnO/AgCl composites prepared by high-energy ball milling showed excellent photocatalytic activity for RhB degradation and 1,4-DHP dehydrogenation under visible-light irradiation.

Amin M, Kaneti Y, Suendo V. Role of Urea on Structural, Textural, and Optical Properties of Macroemulsion-assisted Synthesized Holey ZnO Nanosheets for Photocatalytic Applications

Using a macroemulsion-assisted solvothermal method, the present study produces holey ZnO nanosheets exhibiting the hexagonal wurtzite crystal structure. In the synthetic process, urea is employed as a hydrolyzing agent. Its...

Controlled titration-based ZnO formation

Hexamethylenetetramine (HMTA) is commonly used as a base releasing agent for the synthesis of ZnO under mild aqueous conditions. HMTA hydrolysis leads to gradual formation of a base during the reaction. Use of HMTA, however, does have limitations: HMTA hydrolysis yields both formaldehyde and ammonia, it provides no direct control over the ammonia addition rate or the total amount of ammonia added during the reaction, it results in a limited applicable pH range and it dictates the accessible reaction temperatures. To overcome these restrictions, this work presents a direct base titration strategy for ZnO synthesis in which a continuous base addition rate is maintained. Using this highly flexible strategy, wurtzite ZnO can be synthesized at a pH >5.5 using either KOH or ammonia as a base source at various addition rates and reaction pH values. In situ pH measurements suggest a similar reaction mechanism to HMTA-based synthesis, independent of the varied conditions. The type and concentration of the base used for titration affect the reaction product, with ammonia showing evidence of capping behaviour. Optimizing this strategy, we are able to influence and direct the crystal shape and significantly increase the product yield to 74% compared to the ∼13% obtained by the reference HMTA reaction.

Incorporating W cations into ZnO nanosheets: an efficient method towards ZnO/ZnWO4 photocatalysts for highly effective degradation of organic compounds under UV and visible-light irradiation

Novel ZnO/ZnWO₄ photocatalysts were synthesized for the removal of RhB dye with an excellent photocatalytic performance.

Hydrothermal synthesis and characterization of Zinc Oxide nanoparticles of various shapes under different reaction conditions

Zinc Oxide (ZnO) nanoparticles were synthesized by hydrothermal method under different conditions and studied various properties. FTIR studies proved the presence of ZnO bonding and purity of the samples. Grain size was found to be decreased with the increase of reaction temperature and increased with reaction time. TEM images show formation of nanorods under same reaction temperature, also nanoflowers and nanospheres for different temperatures. Intensity of luminescence peaks is found to be changed with variation in interplanar spacing. UV–vis spectra helped to identify the increased photon absorption in particles of bigger size. Change in bandgap value is also observed due to the difference in size of nanoparticles.

Soft-template-assisted synthesis: a promising approach for the fabrication of transition metal oxides

The past few decades have witnessed transition metal oxides (TMOs) as promising candidates for a plethora of applications in numerous fields. The exceptional properties retained by these materials have rendered them of paramount emphasis as functional materials. Thus, the controlled and scalable synthesis of transition metal oxides with desired properties has received enormous attention. Out of different top-down and bottom-up approaches, template-assisted synthesis predominates as an adept approach for the facile synthesis of transition metal oxides, owing to its phenomenal ability for morphological and physicochemical tuning. This review presents a comprehensive examination of the recent advances in the soft-template-assisted synthesis of TMOs, focusing on the morphological and physicochemical tuning aided by different soft-templates. The promising applications of TMOs are explained in detail, emphasizing those with excellent performances.

Thermal Annealing Induced Controllable Porosity and Photoactive Performance of 2D ZnO Sheets

Porous ZnO sheets containing various degrees of a nanoscaled pore were successfully synthesized using a simple hydrothermal method and various postannealing procedures. The porosity features of the ZnO sheets can be easily tuned by changing both the annealing temperature and annealing atmosphere. The dense porous nature of ZnO sheets is beneficial to enhance light absorption. Moreover, the substantially increased oxygen vacancies in the ZnO sheets were observed especially after the hydrogen treatment as revealed in the X-ray photoelectron spectroscope and photoluminescence analyses. The high density of surface crystal defect enhanced the photoinduced electron-hole separation rate of the ZnO sheets, which is crucial for an improved photoactivity. The porous ZnO sheets formed at a hydrogen atmosphere exhibited superior photoactive performance than the porous ZnO sheets formed at the high-temperature ambient air annealing. The dense pores and massive crystal defects formed by a hydrogen atmosphere annealing in the ZnO crystals might account for the observed photoactive behaviors in this study.

Novel synthesis of ZnO by Ice-cube method for photo-inactivation of E. coli

The ZnO particle with varieties of morphology was prepared from ice-cube of zinc ammonium complex at boiling water surface in 1 min induction of thermal shock. The zinc ammonium complex in ice cube was developed using zinc acetate and biologically activated ammonia in 1 hr and kept in the freezer. Temperature gradient behaviour of the water medium during thermal shock was captured by the thermal camera and thermometer. Morphology study revealed a variety of flower-like ZnO particles with variable size from 1.0 to 2.5 μm. Further, ZnO particle morphologies were tuned by adding trisodium citrate and hexamine to obtain uniform spherical (2–3 μm) and flower (3–4 μm) shapes, respectively. XRD patterns revealed that all ZnO samples are of a hexagonal structure. Photocatalytic inactivation of E. coli has been investigated using various particle morphologies of ZnO in an aqueous solution/overcoated glass slide under sunlight. The photo-inactivation of E. coli by ZnO particles in suspension condition was better when compared to a coated glass slide method. AFM study confirmed the destruction of bacterial cell wall membrane by the photocatalytic effect. The particles morphology of photocatalyst is well dependent on antibacterial activity under sunlight.

Rapid sunlight-driven mineralisation of dyes and fungicide in water by novel sulphur-doped graphene oxide/Ag3VO4 nanocomposite

A semiconductor photocatalyst was prepared in facile, standard conditions by integrating 1% metal-free, sulphur-doped graphene oxide (sGO) as cocatalyst and Ag₃VO₄ as photocatalyst and characterised via spectroscopic, microscopic and voltammetric techniques. The catalytic activity was performed on notable water pollutants like textile dyes and fungicide employing various techniques. Cationic dyes such as methylene blue and rhodamine B were degraded > 99% with above 90% organic carbon content removal indicating total mineralisation while anionic dyes were degraded 75-80% in 1 h. For the first time, a dithiocarbamate fungicide thiram is degraded to give thiourea as a product in 1 h. Photocatalysis follows pseudo-first order kinetics with rate 3.67, 49.50 and 3.19 times higher than Ag₃VO₄, sGO and GO-Ag₃VO₄ respectively with excellent stability and recyclability. One percent sGO aided excellent carrier separation boosted by electrons and surface defects from sGO, morphology and n-n heterojunction formation. The catalyst efficiently removed 82.8% of the total organic carbon content of a real water sample from the textile mill under 2-h sunlight irradiation.

Nitrogen doped carbon quantum dots and GO modified WO3 nanosheets combination as an effective visible photo catalyst

Nitrogen doped carbon quantum dots (NCQDs) based highly efficient ternary photocatalyst are fabricated by modifying surface of GO incorporated WO₃ nano-sheets. XRD confirmed the formation of monoclinicWO₃ nano-sheets. All the characteristic peaks of WO₃, GO and NCQDs are obvious in XRD patterns of WO₃/GO/NCQDs ternary photocatalysts confirming successful fabrication of the photocatalysts. SEM images showed that WO₃ host matrix is distorted after incorporation of GO and NCQDs owing to lower interfacial tension. The surface of WO₃ nano-sheets is modified with morphological defects making more active sites available. UV-vis spectra exhibited extended visible light absorption and remarkable reduction of WO₃ band gap energy. The photoluminescence spectra confirmed the efficient charge separation in NCQDs modified ternary photocatalyst. The synthesized composites were applied for the photocatalytic degradation of harmful organic dye i.e. methyl orange (MO). The ternary composites represented the excellent photocatalytic activity as compared to binary and pure WO₃ photocatalysts. This enhanced photocatalytic activity is attributed to the availability of active sites, extended light absorption in visible region and enhanced charge separation efficiency.

High efficient photo detector by using ZnO nanowire arrays on highly aligned electrospun PVDF-TrFE nanofiber film

Zinc oxide(ZnO) is a versatile semiconductor material and its use is expanding into photoelectric applications. Anisotropic growth characteristics of ZnO are advantageous for growing a nanowire structure. ZnO nanowire based sensors exhibit enhanced performance in terms of photodetection due to their large specific surface area. ZnO nanowires on a highly aligned electrospun poly(vinylidene fluoride-co-trifluoroethylene) (PVDF-TrFE) nanofiber-based film are fabricated high performance ultraviolet (UV) detector. The movement of photo-induced electrons from ZnO nanowires is more effective in aligned electrospun film substrate (R_sq,off/R_sq,on = 551.0) than random electrospun film substrate (R_sq,off/R_sq,on = 47.8) under continuous UV irradiation. The current difference is 3.98 times higher on ZnO nanowires on aligned electrospun film than it is on random electrospun film in UV light on-off cycles. As a result, we improve the performance of photo sensitivity of electrospun nanofiber-based ZnO nanowires through controlling the directionality and fabrication time of the electrospun film without additional processes.

The Role of ALD-ZnO Seed Layers in the Growth of ZnO Nanorods for Hydrogen Sensing

Hydrogen is one of the most important clean energy sources of the future. Because of its flammability, explosiveness, and flammability, it is important to develop a highly sensitive hydrogen sensor. Among many gas sensing materials, zinc oxide has excellent sensing properties and is therefore attracting attention. Effectively reducing the resistance of sensing materials and increasing the surface area of materials is an important issue to increase the sensitivity of gas sensing. Zinc oxide seed layers were prepared by atomic layer deposition (ALD) to facilitate the subsequent hydrothermal growth of ZnO nanorods. The nanorods are used as highly sensitive materials for sensing hydrogen due to their inherent properties as oxide semiconductors and their very high surface areas. The low resistance value of ALD-ZnO helps to transport electrons when sensing hydrogen gas and improves the sensitivity of hydrogen sensors. The large surface area of ZnO nanorods also provides lots of sites of gas adsorption which also increases the sensitivity of the hydrogen sensor. Our experimental results show that perfect crystallinity helped to reduce the electrical resistance of ALD-ZnO films. High areal nucleation density and sufficient inter-rod space were determining factors for efficient hydrogen sensing. The sensitivity increased with increasing hydrogen temperature, from 1.03 at 225 °C, to 1.32 at 380 °C after sensing 100 s in 10,000 ppm of hydrogen. We discuss in detail the properties of electrical conductivity, point defects, and crystal quality of ALD-ZnO films and their probable effects on the sensitivity of hydrogen sensing.

A highly efficient porous rod-like Ce-doped ZnO photocatalyst for the degradation of dye contaminants in water

A mild and simple method was developed to synthesize a highly efficient photocatalyst comprised of Ce-doped ZnO rods and optimal synthesis conditions were determined by testing samples with different Ce/ZnO molar ratios calcined at 500 °C for 3 hours via a one-step pyrolysis method. The photocatalytic activity was assessed by the degradation of a common dye pollutant found in wastewater, rhodamine B (RhB), using a sunlight simulator. The results showed that ZnO doped with 3% Ce exhibits the highest RhB degradation rate. To understand the crystal structure, elemental state, surface morphology and chemical composition, the photocatalysts were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM) and inductively coupled plasma emission spectroscopy (ICP), respectively. The newly developed, robust, field-only surface integral method was employed to explore the relationship between the remarkable catalytic effect and the catalyst shape and porous microstructure. The computational results showed that the dipole-like field covers the entire surface of the rod-like Ce-doped ZnO photocatalyst and is present over the entire range of wavelengths considered. The optimum degradation conditions were determined by orthogonal tests and range analysis, including the concentration of RhB and catalyst, pH value and temperature. The results indicate that the pH value is the main influential factor in the photocatalytic degradation process and the optimal experimental conditions to achieve the maximum degradation rate of 97.66% in 2 hours are as follows: concentration (RhB) = 10 mg/L, concentration (catalyst) = 0.7 g/L, pH 9.0 and T = 50 °C. These optimum conditions supply a helpful reference for large-scale wastewater degradation containing the common water contaminant RhB.

Zinc-Coordinated Nitrogen-Codoped Graphene as an Efficient Catalyst for Selective Electrochemical Reduction of CO2 to CO

Electrochemical reduction of CO₂ to value-added chemicals by using renewable electricity offers a promising strategy to deal with rising CO₂ emission and the energy crisis. Single-site zinc-coordinated nitrogen-codoped graphene (Zn-N-G) catalyzes the electrochemical reduction of CO₂ to CO. The Zn-N-G catalyst exhibits excellent intrinsic activity toward CO₂ reduction, reaching a faradaic efficiency of 91 % for CO production at a low overpotential of 0.39 V. X-ray absorption fine structure and X-ray photoelectron spectroscopy both confirm the presence of isolated Zn-N_x moieties, which act as the key active sites for CO formation. DFT calculations reveal the origin of enhanced activity for CO₂ reduction on Zn-N-G catalysts. This work provide further understanding of the active centers on transition metal-nitrogen-carbon (M-N-C) catalysts for electrochemical reduction of CO₂ to CO.

Preparation and Enhanced Photocatalytic Properties of 3D Nanoarchitectural ZnO Hollow Spheres with Porous Shells

By using ginkgo leaves (GL) as template and Zn(CH₃COO)₂∙2H₂O as Zn source, a series of ZnO samples with special morphology were prepared via a template-assisted two-steps method without adding any other additives. The degradation of the dye MB was used to evaluate the photocatalytic property of the as-prepared samples. The results showed that when a proper amount of the template was used, a 3D nanoarchitectural ZnO hollow sphere with porous sphere shell assembled by well-distributed nanoparticles was obtained and its photocatalytic activity was much higher than that of ZnO nanoparticles. The special morphology of the sample was herein considered to be very helpful for highly efficient adsorption and activation of reactant molecules by multi-times adsorption-desorption-adsorption, efficient absorption of irradiation light by repeated absorption-reflection-absorption, and efficient separation of the photogenerated e⁻-h⁺ pairs. In addition, the formation of 3D structure of sample ZnO was also discussed.

Multiscale design of ZnO nanostructured photocatalysts

Light absorbance and crystal orientation, not surface area, determine the photocatalytic efficiency of immobilize ZnO nanowire films.

Two-Dimensional Transition Metal Oxide and Chalcogenide-Based Photocatalysts

Two-dimensional (2D) transition metal oxide and chalcogenide (TMO&C)-based photocatalysts have recently attracted significant attention for addressing the current worldwide challenges of energy shortage and environmental pollution. The ultrahigh surface area and unconventional physiochemical, electronic and optical properties of 2D TMO&Cs have been demonstrated to facilitate photocatalytic applications. This review provides a concise overview of properties, synthesis methods and applications of 2D TMO&C-based photocatalysts. Particular attention is paid on the emerging strategies to improve the abilities of light harvesting and photoinduced charge separation for enhancing photocatalytic performances, which include elemental doping, surface functionalization as well as heterojunctions with semiconducting and conductive materials. The future opportunities regarding the research pathways of 2D TMO&C-based photocatalysts are also presented.

Hydrothermal synthesis of In2O3 nanoparticles hybrid twins hexagonal disk ZnO heterostructures for enhanced photocatalytic activities and stability

In₂O₃ nanoparticles hybrid twins hexagonal disk (THD) ZnO with different ratios were fabricated by a hydrothermal method. The as-obtained ZnO/In₂O₃ composites are constituted by hexagonal disks ZnO with diameters of about 1 μm and In₂O₃ nanoparticles with sizes of about 20-50 nm. With the increase of In₂O₃ content in ZnO/In₂O₃ composites, the absorption band edges of samples shifted from UV to visible light region. Compared with pure ZnO, the ZnO/In₂O₃ composites show enhanced photocatalytic activities for degradation of methyl orange (MO) and 4-nitrophenol (4-NP) under solar light irradiation. Due to suitable alignment of their energy band-gap structure of the In₂O₃ and ZnO, the formation of type п heterostructure can enhance efficient separation of photo-generate electro-hole pairs and provides convenient carrier transfer paths.

Pt/ZnO@C Nanocable with Dual-Enhanced Photocatalytic Performance and Superior Photostability

To improve the photocatalytic activity and photostability of ZnO, a novel cable-like Pt/ZnO@C composite is successfully fabricated by coating a 3-5 nm hydrothermal carbon (HTC) layer on the surface of the Pt nanoparticle-modified ZnO nanowire. After investigating the optical and photoelectrochemical performance in detail, it is found that the Pt/ZnO@C nanocable shows a dual-enhanced migration efficiency for the photoinduced surface electrons, distributing to the modified Pt nanoparticles and the coated HTC layer. Consequently, the Pt/ZnO@C nanocable exhibits a dual-enhanced photocatalytic activity for the degradation of various organic pollutants under the UV light irradiation. The coated HTC layer can also play a role in suspending the ZnO photocorrosion and significantly improves the photostability of the Pt/ZnO@C nanocable. Furthermore, the photocatalysis and photocorrosion mechanism of the Pt/ZnO@C nanocable is proposed and discussed in terms of its structural feature and photoelectrochemical property. The resultant Pt/ZnO@C nanocable with the unique HTC layer-coated structure will probably stimulate to design and synthesize more HTC-hybridized composites with a superior photocatalytic or photoelectrocatalytic performance.

Superior adsorption performance for triphenylmethane dyes on 3D architectures assembled by ZnO nanosheets as thin as ∼1.5nm

The 3-dimensional hierarchical ZnO flower-like architectures have been synthesized in a Zn(Ac)2·2H2O-Na2SeO3-KBH4-pyridine solvothermal system at 100°C for 24h. The flower-like architecture is assembled from ZnO nanosheets with a thickness of ∼1.5nm, and the flower-like architecture specific surface area is 132m(2)/g. When the ZnO flower-like architecture is used as the adsorbent for acid fuschin (AF), malachite green (MG), basic fuchsin (BF), congo red (CR) and acid red (AR) in water, the adsorption capacities for AF, MG, BF, CR and AR are 7154.9, 2587.0, 1377.9, 85.0 and 38.0mg/g, respectively. Evidently, the as-obtained ZnO flower-like architectures show excellent adsorption performances for triphenylmethane dyes, and the adsorption capacity of 7154.9mg/g for AF is the highest of all adsorbents for dyes. The adsorption mechanism can be attributed to the electrostatic attraction and the formation of ion-association complex between triphenylmethane dyes and ZnO hierarchical flower-like architectures.

PdCo/Pd-Hexacyanocobaltate Hybrid Nanoflowers: Cyanogel-Bridged One-Pot Synthesis and Their Enhanced Catalytic Performance

Elaborate architectural manipulation of nanohybrids with multi-components into controllable 3D hierarchical structures is of great significance for both fundamental scientific interest and realization of various functionalities, yet remains a great challenge because different materials with distinct physical/chemical properties could hardly be incorporated simultaneously into the synthesis process. Here, we develop a novel one-pot cyanogel-bridged synthetic approach for the generation of 3D flower-like metal/Prussian blue analogue nanohybrids, namely PdCo/Pd-hexacyanocobaltate for the first time. The judicious introduction of polyethylene glycol (PEG) and the formation of cyanogel are prerequisite for the successful fabrication of such fascinating hierarchical nanostructures. Due to the unique 3D hierarchical structure and the synergistic effect between hybrid components, the as-prepared hybrid nanoflowers exhibit a remarkable catalytic activity and durability toward the reduction of Rhodamine B (RhB) by NaBH₄. We expect that the obtained hybrid nanoflowers may hold great promises in water remediation field and beyond. Furthermore, the facile synthetic strategy presented here for synthesizing functional hybrid materials can be extendable for the synthesis of various functional hybrid nanomaterials owing to its versatility and feasibility.