3D Zinc Research Articles

Anion-Controlled Synthesis of Enantiomeric Twofold Interpenetrated 3D Zinc(II) Coordination Polymer with Ligand Substitution-Induced Single-Crystal-to-Single-Crystal Transformation and Photocatalysis

An anion-controlled synthesis of a new three-dimensional (3D) “racemate”, an enantiomorphic twofold interpenetrated 3D zinc(II) coordination polymer containing bridging glutarate (glu) and 4,4′-bipyridine (4,4′-bipy) ligands, {[Zn4(H2O)2(4,4′-bipy)4(glu)3](NO3)2}n, 1 (P21/c), with ligand substitution-induced single-crystal-to-single-crystal (SCSC) transformation and photocatalysis for dye degradation was studied. The influence of a counteranion in zinc(II) starting materials and synthetic techniques upon the phase formation were explored. The complex 1 was successfully synthesized from zinc(II) nitrate salt via microwave-assisted techniques as well as the conventional hydrothermal technique, whereas the employment of zinc(II) acetate or sulfate salt yielded a two-dimensional coordination polymer, [Zn(4,4′-bipy)(glu)]n, 2 (P1̅), and the use of zinc(II) chloride led to a one-dimensional (1D) zigzag chain, [Zn(4,4′-bipy)Cl2]n 3 (C2/c). The synthetic-method-dependent formation was illustrated as the microwave-assisted techniques and conventional hydrothermal technique enabled the formation of crystalline-phase pure 1, while the sonochemical synthesis provided mixed crystalline-phases of 1 and 2. In the structure of 1, the 4,4′-bipy ligand links dinuclear Zn(II) building units into 1D chains along the [1̅01] direction. The glu2– ligand acts as tethering linkers expanding the structure into a cationic 3D coordination polymer that interpenetrates with its enantiomer to give a 3D solid-state “racemate”. Powder X-ray diffraction revealed that the ligand substitution-induced SCSC transformation of the twofold interpenetrated 3D framework, 1 (P21/c), which was triggered by chloride, led to a 1D zigzag chain, 3 (C2/c), whereas the bromide-triggered reaction led to a mixed crystalline phase between the isostructural 1D zigzag chain, [Zn(4,4′-bipy)Br2]n, 4 (C2/c), and its polymorph, [Zn(4,4′-bipy)Br2]n, 5 (P212121). The photocatalysis for the methyl orange degradation of 1 was studied.

Antimicrobial Activity of Pyrazinamide Coordination Frameworks Synthesized by Mechanochemistry.

The urge for the development of a more efficient antibiotic crystalline forms led us to the disclosure of new antibiotic coordination frameworks of pyrazinamide, a well-known drug used for the treatment of tuberculosis, with some of the novel compounds unravelling improved antimycobacterial activity. Mechanochemistry was the preferred synthetic technique to yield novel compounds, allowing the reproduction of a 1D zinc framework, the synthesis of a novel hydrogen bonding manganese framework, and three new compounds with silver. The structural characterization of the novel forms is presented along with stability studies. The increased antimicrobial activity of the new silver-based frameworks against Escherichia coli, Staphylococcus aureus, and Mycobacterium smegmatis is particularly relevant.

Optoelectronic and solar cell applications of ZnO nanostructures

ZnO has risen as a vital material for electron transportation in a greater number of solar cells based on nanostructures because of its abundance, nontoxicity, and high electron mobility. We performed first principle calculations on structural, optical, and electronic properties of 2D zinc oxide monolayer and bilayer honeycomb structures. Our work includes study of wurtzite, zinc blende, and tetragonal bulk structures revealing dimensionality effects. Calculated electronic band gaps affirm the band gap to be direct for all structures, having range (0.561–0.761 eV) using GGA and (0.766–0.910 eV) using LDA+U for bulk structures, while for bilayer and monolayer it is 1.419 eV (GGA), 1.413 eV (LDA+U) and 1.691 eV (GGA), 1.683 eV (LDA+U) respectively. The shrunken Zn–O bond length of monolayer predicts it to be more ionic compared to bulk structures. Moreover, the optical properties like absorption, dielectric function of all honeycomb-like structures are also analyzed. To make a comparison of ionicity of all structures Hirshfeld analysis is made to investigate charge transfer. Absorption spectra are calculated to understand the optical behavior of these systems, especially in visible portion. The absorption efficiency of ZnO was investigated as it could be a promising material for the use in solar cell. For the future, we expect that ZnO would be a potential candidate for solar cell application.

General Strategy for Fabrication of Ordered One Dimensional Inorganic Structures by Electrospinning: Structural Evolution From Belt to Solid via Hollow Tubes

Super‐structured hollow materials are the subject of intense research due to their attracting properties and diverse applications. Despite their significance, it still remains a crucial challenge to develop a simple and well‐organized method to prepare the hollow tubes with controlled architectures. Herein, a general route to prepare structurally well‐defined 1D zinc oxide (ZnO) structures by a single‐spinneret electrospinning method coupled with thermal treatment is demonstrated for the first time and subsequently designated to identify high‐performance materials for catalytic application. Two critical factors including tailoring the precursor amount and colloidal‐stability of the precursor play critical role in tuning the structure precisely. The careful optimization of processing conditions enables chronological structural evolution from tubular to solid fiber structures composed of nanograins. These ZnO complex hollow structures showcase excellent photocatalytic performance; single nanograined wall hollow tubes manifest the high‐catalytic performance over other samples with remarkable cycling stability. Benefitting from fabrication adaptability, different types of metal oxide hollow tubes are prepared that indicates the generality of the method. The proposed method postulates new insights for the development of electrospun hollow‐structured fibers in a simple, cost‐effective, and industrially feasible manner which holds apparent potential in many sectors.

Maximum piezoelectricity in a few unit-cell thick planar ZnO – A liquid metal-based synthesis approach

Synthesizing two dimensional (2D) nanomaterials with controlled sub-nanometer thicknesses from non-layered crystals presents both significant challenges and vast opportunities. However, mechanical exfoliation techniques and physical/wet chemical deposition processes are widely disadvantageous for applicability to non-layered structures. Here we have utilized a simple self-limiting approach to prepare large sheets of 2D zinc oxide (ZnO) at the metal-melt/air interface. These ultra-thin sheets demonstrated highly crystalline hexagonal structures. The specific ZnO hexagonal sheet thickness and its interaction with the substrate were found to have a critical impact on d33. This unusual structure resulted in an exceptionally high out of plane piezoelectricity, yielding a giant value of 80 ± 0.8 pm/V at 2.5 unit-cell thickness for d33, which is 5 Zn-O layers in the wurtzite crystal. This out of plane piezoelectricity value is approximately 8 times larger than that of the value for bulk ZnO. Theoretical studies were carried out to elucidate the impact of the thickness and the substrate’s role on the polarization of the layers. The existence of a large piezoelectricity offered by the synergy of the substrate and specific thickness of ultrathin films offers the opportunity for other groups of potentially piezoelectric materials to be explored.

Easily prepared one dimensional zinc oxide crystals, characterization and application in UV photodetector

One dimensional (1D) zinc oxide crystals (ZCs) were prepared using a simple wet chemical route. Structural and morphological characterizations were performed through x-ray diffraction, scanning electron microscopy and transmission electron microscopy. Thus, the prepared sample confirmed the hexagonal crystal phase of zinc oxide and displayed a uniform morphology with 1D structure. The average length and diameter of the prepared ZnO based 1D structure were found to be 8 µm and 0.7 µm respectively. Energy dispersive x-ray spectroscopy and Fourier transform infrared spectroscopy were performed to study the chemical purity of the sample. The prepared sample also showed its excellent ability in ultra-violet (UV) absorption with a sharp absorption peak at 369 nm and a photoluminescence (PL) property with a sharp emission peak at 384 nm. Finally, a UV photodetector device was fabricated with the prepared sample and its photoconductivity with a significant change in resistance was observed upon UV exposure.

Highly sensitive detection of nitrobenzene by a series of fluorescent 2D zinc(ii) metal-organic frameworks with a flexible triangular ligand.

Four fluorescent zinc(ii) metal–organic frameworks, namely [Zn(HCIA)(4,4′-bipy)] (1), [Zn2(CIA)(OH)(1,4-bibz)1.5]·H2O (2), [Zn(CIA)(OH) (4,4′-bbpy)] (3), and [Zn2(HCIA) (4,4′-bimp)]·H2O (4), were prepared hydrothermally with a flexible triangular ligand (H3CIA) and a series of linear N-donor ligands (H3CIA = 5-(2-carboxybenzyloxy) isophthalic acid, 4,4′-bipy = 4,4′-bipydine, 1,4-bibz = 1,4-bis(1-imidazoly)benzene; 4,4′-bbpy = 4,4′-bis (imidazolyl) biphenyl; 4,4′-bimp = 4,4′-bis (imidazole-1-ylethyl) biphenyl). Structural analyses revealed that complex 1 exhibited a 2D brick-like network structure based on the basic bimetallic ring, 2 was also a 2D interspersed structure from the 1D tubular structure, compound 3 possessed a 2D (4,4) network with 4,4′-bbpy occupying the holes, and complex 4 displayed a 2D network from the 1D ladder-like chain. The thermal stabilities and fluorescent properties of these complexes were investigated in the solid state. The fluorescent sensing experiments revealed that all Zn-MOFs could highly sensitively detect nitrobenzene in aqueous solution, which indicated that these materials can be used as fluorescent probes for the detection of nitrobenzene.

A synergetic and sensitive physostigmine pesticide sensor using copper complex of 3D zinc (II) phthalocyanine-SWCNT hybrid material

2,3,9,10,16,17,23,24-Octakis (4-methyl-2,6-bis((prop-2-yn-1-yloxy)methyl)phenoxy) phthalocyaninato zinc(II) (Pc) bearing sixteen terminal ethynyl groups was synthesized and attached to SWCNT (Single-walled carbon nanotube) covalently to obtain three dimensional porous hybrid material (SWCNT-Pc 3D) and its copper complex (Cu-SWCNT-Pc 3D). The structural characterization and electrochemical sensor features of the Cu-SWCNT-Pc hybrid towards to physostigmine pesticide were performed. A fast, direct and suitable determination method for physostigmine detection was offered. The designed sensor, Cu-SWCNT-Pc 3D/GCE (glassy carbon electrode) shows sensitivity ca 1.8, 4.3 and 2.8 times more than that of SWCNT/GCE, SWCNT-Pc-noncovalent/GCE and SWCNT-Pc 3D/GCE in terms of peak heights while bare and Pc/GCE had almost no voltammetric response to 2 μM physostigmine in PBS at a pH of 7.0. The limit of detection and quantification of physostigmine determination with Cu-SWCNT-Pc 3D/GCE were found to be 53 and 177 nM in the range of 0.1–4.8 μM, respectively. This study demonstrated that the modification of the GCE with Cu-SWCNT-Pc 3D as an electrochemical sensor was acted as catalytic role toward physostigmine presence of other interfering pesticides as high sensitivity and selectivity. The electrochemical determination of physostigmine in real samples was performed under the optimized conditions, also accuracy of the electrochemical determination method was evaluated with HPLC as a standard determination method.

One Dimensional ZnO Nanostructures: Growth and Chemical Sensing Performances.

Recently, one-dimensional (1D) nanostructures have attracted the scientific community attention as sensitive materials for conductometric chemical sensors. However, finding facile and low-cost techniques for their production, controlling the morphology and the aspect ratio of these nanostructures is still challenging. In this study, we report the vapor-liquid-solid (VLS) synthesis of one dimensional (1D) zinc oxide (ZnO) nanorods (NRs) and nanowires (NWs) by using different metal catalysts and their impact on the performances of conductometric chemical sensors. In VLS mechanism, catalysts are of great interest due to their role in the nucleation and the crystallization of 1D nanostructures. Here, Au, Pt, Ag and Cu nanoparticles (NPs) were used to grow 1D ZnO. Depending on catalyst nature, different morphology, geometry, size and nanowires/nanorods abundance were established. The mechanism leading to the VLS growth of 1D ZnO nanostructures and the transition from nanorods to nanowires have been interpreted. The formation of ZnO crystals exhibiting a hexagonal crystal structure was confirmed by X-ray diffraction (XRD) and ZnO composition was identified using transmission electron microscopy (TEM) mapping. The chemical sensing characteristics showed that 1D ZnO has good and fast response, good stability and selectivity. ZnO (Au) showed the best performances towards hydrogen (H2). At the optimal working temperature of 350 °C, the measured response towards 500 ppm of H2 was 300 for ZnO NWs and 50 for ZnO NRs. Moreover, a good selectivity to hydrogen was demonstrated over CO, acetone and ethanol.

One pot, three dimensionalities: 1D, 2D and 3D zinc coordination polymers with both N- and O- linkers produced in same reaction

MeOH/H2O reagent diffusion lead to the self-assembly of three CPs (coordination polymers), all with different dimensionalities. The structures of all three compounds were elucidated via SC-XRD (single-crystal X-ray diffraction), the 3D CP is the known material [Zn (ATA) (4,4′-bpy)]n (1), whereas both the 2D and the 1D CPs are novel. The individual sheets in the 2D MOF {[Zn4(OH) 2 (ATA)3 (4,4′-bpy)2]·(H2O)3}n (2) mechanically interlock forming a 2D+2D→3D interpenetration mode. The structure of the 1D CP, {[Zn (bipy) (H2O)4]·ATA}n, (3) although resolved, SC-XRD experiments had data quality issues, likely as a result of unresolvable pseudo-translational effects. The isomorphous cobalt analogue {[Co(bipy) (H2O)4]·ATA}n (4) was synthesised and the elucidation of its structure was in turn able to help shed light on the finer details of 3 and its intermolecular interactions. The ndca/4-bpdb analogues of 3 and 4 were also synthesised, namely: {[Zn (4-bpdb) (H2O)4]·ndca}n (5) and {[Co(4-bpdb) (H2O)4]·ndca}n (6) which exhibited markedly different intermolecular interactions to 3 and 4 as a result of the mismatched linker length.

Design of Ti3C2ZnOAlN ternary nanocomposite for photocatalytic antifouling: a first-principle study

Photocatalytic antifouling has been proved to be an efficient method to restrain marine biofouling. In this work, a new photocatalyst with superior photocatalytic performance was designed based on first-principle calculation. Two-dimensional (2D) zinc oxide (ZnO) and aluminum nitride (AlN) based on (001) crystal plane were selected to construct the new catalyst, which could effectively adjust their band gap and band edge alignment. However, the stress and strain under lattice distortion would damage their direct band gap characteristics, even affecting their stability. To eliminate these effects, titanium carbide (Ti3C2) MXenes was used as substrate to carry 2D-ZnO and 2D-AlN (Ti3C2ZnOAlN), in which Ti3C2 played as a co-catalyst. The results reveal that the designed composite structure has a low work function and is a type II heterostructure, which can achieve the separation of photo-generated electrons and holes efficiently. The phonon frequency comparison results indicate that participation of Ti3C2 greatly improves the dynamic stability of the structure. An asymmetric built-in electric field at the interface further reduces the work function and is considered to be the main reason for the rapid migration of carriers in the direction of the interface. At the same time, the light absorption peaks in the Ti3C2ZnOAlN composite structure are red-shifted and produce a high coincidence with the main irradiation intensity of solar flux. The triple interfaces are also helpful to improve the utilization of incident photons in all directions. According to the results of the band edge position and Nernst equation, it can be concluded that the Ti3C2ZnOAlN composite material can meet the ROS reaction conditions under any pH environments, so it should be an environmentally adaptable photocatalytic sterilization material for antifouling.

Selective nitrogen doping on carbon cloth to enhance the performance of zinc anode

Metallic zinc is attractive anode material of rechargeable aqueous Zn-based batteries due to its ambient stability, high volumetric capacity, and abundant reserves. Nonetheless, Zn anodes suffer from issues such as low coulombic efficiency (CE), large polarization and dendrite formation. Herein, uniform Zn electrodeposition is reported on carbon substrates by selective nitrogen doping. Combined experimental and theoretical investigations demonstrate that pyrrolic and pyridinic nitrogen doped in carbon play beneficial effect as zinc-philic sites to direct nucleation and growth of metallic Zn, while negligible effect is observed for graphite nitrogen in Zn plating. The carbon cloth with modified amount of doped pyrrolic and pyridinic nitrogen stabilizes Zn plating/stripping with 99.3% CE after 300 cycles and significantly increases the deliverable capacity at high depth of charge and discharge compared to undoped carbon substrate and Zn foil. This work provides a better understanding of heteroatom doping effect in design and preparation of stable 3D carbon-supported zinc anode.

2-D zinc ferrite “moss” furred on 3-D zinc oxide tetrapods to boost detection sensitivity of hydrogen sulfide

In this study, a two-/three-dimension (2D/3D) architecture was designed and fabricated by a facile dip-calcination procedure. In this design, moss-like zinc ferrite (ZnFe2O4) was grown on the surface of 3D zinc oxide tetrapods (ZnO-T) to form a semiconductor heterostructure. This unique architecture features the merits of copious porosities that facilitate gas circulation and boost active gas-absorption sites, making it exceedingly applicable for gas detection. It was found that this architecture was very sensitive towards hydrogen sulfide gas (H2S, 2 ppm, 250 °C, 65% RH) with ultrafast response and recovery time of 2 and 9 s, respectively. Further, low-concentration gas tests at 250 °C, 65% RH unraveled that it showed quick response even when the concentration of H2S gas was as low as 0.6 ppb.

RETRACTED ARTICLE: A new 3D zinc (II)-coordination polymer: treatment activity on lymphoma combined with doxorubicin via regulating apoptotic genes expression

We, the Editors and Publisher of the journal Inorganic and Nano-Metal Chemistry, have retracted the following article: Xin-Sheng Han, Ting Li, Xing-An Zhang & Jun Lu. A new 3D zinc (II)-coordination polymer: treatment activity on lymphoma combined with doxorubicin via regulating apoptotic genes expression, Inorganic and Nano-Metal Chemistry. 2021, 51:4, 467-473, DOI: 10.1080/24701556.2020.1793359 Since publication, concerns have been raised about the integrity of the data in the article. When approached for an explanation, the authors have been unable to address the concerns raised and have not been able to provide sufficient supporting information. As verifying the validity of published work is core to the integrity of the scholarly record, we are therefore retracting the article. The corresponding author listed in this publication has been informed. The authors do not agree with the retraction. We have been informed in our decision-making by our policy on publishing ethics and integrity and the COPE guidelines on retractions. The retracted article will remain online to maintain the scholarly record, but it will be digitally watermarked on each page as ‘Retracted’.

Fabrication and analysis of piezoelectricity in 0D, 1D and 2D Zinc Oxide nanostructures

The focus of the presented study is to understand the effect of the structure of Zinc Oxide (ZnO) on its piezoelectric behavior. Various nanostructures, including 0D, 1D, and 2D of ZnO, were synthesized by using the hydrothermal method, and these nanostructures were utilized for the fabrication of piezoelectric nanogenerators (PENG). These ZnO nanostructures were characterized using Scanning Electron Microscopy, X-ray Diffraction Spectroscopy, Raman Spectroscopy, Fourier Transform Infrared Spectroscopy, and Photoluminescence Spectroscopy. Piezoelectric current, voltage, and power of the nanogenerator fabricated from all three nanostructures were measured. The maximum power output of 2.4μW/m2 was observed in the case of a 2D structure-based PENG. Simulation models were also designed to mimic the synthesized nanostructures, and their voltage response for the stress applied is compared with their corresponding experimental results. These results show that PENG output can be varied by altering the ZnO structure, which has enormous potential in the battery-less portable electronics and biosensors industry.

Comprehensive experimental study on production of vertically aligned ZnO nanorod thin films and their electrical, optical and antimicrobial properties

One-dimensional (1D) zinc oxide (ZnO) nanomaterials (e.g. nanorods, nanowires) are the most important due to their electrical and optical properties. As the surface-to-volume ratio in ZnO nanorods (NRs) is very high, the surface states have a crucial role on optical and other properties. So, determination of the production parameters of the ZnO-NRs is important. In this study, a well-aligned ZnO-NRs thin film was produced via the sol–gel and hydrothermal methods. For this purpose, in the first step, a ZnO seed layer was coated onto a cleaned microscope glass slide (sizes of 1.25 × 3.75 cm) by the sol–gel spin coating method. In the second step, ZnO-NRs were grown on the ZnO seed layer by the hydrothermal method. Production parameters for the first step, such as type of the zinc salt; type of the solvent; solution concentration; type of the stabilizer; ageing time process of the solution; spin speed; duration of the spin process; number of repeated coating cycle; heating treatment temperature between coating cycles; duration between coating cycles; final heating treatment temperature and final heating treatment duration of the ZnO seed layer, were obtained. Then similar optimization processes were repeated for the second stage for the ZnO-NRs. The crystal structure, morphological and optical properties of all the produced samples were characterized via X-ray diffraction (XRD) spectroscopy; scanning electron microscopy (SEM); and ultraviolet–visible (UV–Vis) spectroscopy. For comparison, ZnO-NR powders were produced via the mechanochemical solid-state combustion method. The electrical conductivity and optical transparency of the ZnO-NR thin film samples were higher than those of the ZnO-NR powder sample. It was also observed that the well-aligned ZnO-NR thin film sample had a higher bactericidal effect against Bacillus thuringiensis than the ZnO-NR powder sample.

A new one‐dimensional coordination polymer synthesized from zinc and guanazole: Superior capture of organic arsenics

Organic arsenic compounds in the environment are a global threat to human health. This threat has created the urgency to develop highly efficient adsorbents with both high adsorption capacity and versatile removal of different arsenic compounds. A novel 1D zinc(II) coordination polymer, formulated as Zn2(datrz)2(bpy)Cl2 (BUC‐70) (datrz = guanazole, bpy = 4,4′‐bipyridine), was successfully synthesized through slow evaporation at room temperature. BUC‐70 exhibited an excellent adsorption capacity toward p‐arsanilic acid (p‐ASA) and roxarsone (ROX) in water, which could be ascribed to As–O–Zn bonding interactions and strong hydrogen‐bonding interactions between the organic arsenics and BUC‐70. The maximum adsorption capacities toward p‐ASA and ROX were 738 and 937 mg·g−1, respectively. BUC‐70 was effective in the removal of p‐ASA and ROX at low concentrations (<5 mg·l−1) from the simulated p‐ASA and ROX wastewater. Furthermore, the as‐synthesized BUC‐70 exhibited good adsorption property toward p‐ASA and ROX in wastewater simulated by lake water and tap water. After adsorptive treatment using BUC‐70, the concentrations of both p‐ASA and ROX were lower than the required concentrations of the drinking water standard of the World Health Organization and the surface water standard of China. Continuous‐flow, fixed‐bed column experiments were performed using BUC‐70 loaded on cotton as packing material to explore the potential large‐scale application.

A Comparative Study of Proton Conduction Between a 2D Zinc(II) MOF and Its Corresponding Organic Ligand

Until now, comparative studies on proton conductivity between organic ligands and related metal-organic frameworks (MOFs) have been very limited. Herein, a stable 2D Zn(II) MOF, [Zn(L)Cl]n (1), has been successfully synthesized by using a zwitterionic-type organic ligand, 2-(1-(carboxymethyl)-1H-benzo[d]imidazol-3-ium-3-yl)acetate (HL). It is found that there are a large amount of free carboxyl groups and hydrogen bonds in the solid-state structure of HL, and a large number of chlorine ions are aligned in the channels of 1, which is favorable to the efficient proton transfer. Correspondingly, the proton conductivity values of 1 and HL are almost of the same order of magnitude under the same conditions. Moreover, the optimal σ value of 1 (4.72 × 10-3 S/cm at 100 °C and 98% relative humidity) is almost four times higher than that (1.36 × 10-3 S/cm) of the HL ligand. On the basis of the crystal data, SEM images, and calculated Ea values, we discuss the differences on proton conductivities and conduction mechanisms of 1 and HL. This report provides an inspiration for the preparation of highly conductive materials with free carboxyl groups and chloride ions.

Highly efficient 3D-ZnO nanosheet photoelectrodes for solar-driven water splitting: Chalcogenide nanoparticle sensitization and mathematical modeling

Three-dimensional (3D) zinc oxide nanosheets (ZnO-NS), assembled on the FTO coated glass substrates after chemical treatment, have been achieved via a simple yet effective chemical bath deposition technique. The exploration of chalcogenide nanoparticle sensitization on ZnO-NS thin-film photoanodes led us to a spectacular enhancement in the photoelectrochemical conversion efficiency for solar-driven water splitting process as compared to the bare 3D-ZnO-NS. The maximum incident photon-to-charge carrier efficiency of bare 3D-ZnO-NS has been enhanced by approximately four folds as a result of cadmium sulfide (CdS) and cadmium selenide (CdSe) sensitization and the efficiency value have reached to 51% at 550 nm. Besides, the maximum charge injection and charge separation efficiencies of the ZnO–CdSe electrodes have been calculated as 93% and 64%, respectively. Numerical examination of the optical absorption and electrical field distribution has been performed via the finite-difference time-domain (FDTD) method in order to investigate the basis of the enhancement in the photoelectrochemical efficiencies of the 3D-ZnO-NS photoelectrodes. FDTD numerical simulation proved that the accumulation of rectangular 2D-nanosheets of ZnO in 3D-microspherical forms enhanced the light absorption significantly. Moreover, FDTD results also verified that the optical absorption of the ZnO electrodes has been extended from ultraviolet to visible region via CdS and CdSe nanoparticle deposition.

Two new Zn (II) bdc Metal-Organic Frameworks based on benzene 1, 4-dicarboxylic acid: Synthesis, Crystal structures, Luminescent properties and Electrochemical studies

Abstract Two new one-dimensional (1D) Zinc Metal organic frame works, [Zn (BDC) (DMF) RT] (or Zn-MOF-1) and [Zn (BDC) (DMF) MW] (or Zn-MOF-2), where H2BDC = Benzene 1, 4 di-carboxylic acid, DMF = N, N-dimethylformamide, RT= Room temperature, MW= Microwave, have been synthesized through Room temperature and Microwave methods respectively. Zn-MOF-1; Zn-MOF-2 material was characterized by FTIR, Powder XRD, FE-SEM, Photo-luminescent, TGA and SXRD measurement. The electrochemical properties of these MOF electrodes were examined by using of Cyclic Voltammetry (CV), Galvanostatic Charge- Discharge (GCD) and Electrochemical Impedance Spectroscopic (EIS) techniques. Crystallographic studies show that the Zn-MOF-1 molecule has a one dimensional network in which the θ ranges from 6.86 to 54.92 with monoclinic P21/c space group, with Volume = 1015.9(4) A. In Zn-MOF-2 molecule θ ranges from 6.72 to 54.94 with monoclinic C2/c space group with Volume = 1265.9(3) A respectively. In comparison with Zn-MOF-1 and Zn-MOF-2 based on BDC derivatives both MOFs show strong luminescence along with red-shift, which indicates that these are the potential candidates for various luminescent applications