Modification Of Zinc Oxide Research Articles

Emerging ZnO Semiconductors for Photocatalytic CO2 Reduction to Methanol.

Carbon recycling is poised to emerge as a prominent trend for mitigating severe climate change and meeting the rising demand for energy. Converting carbon dioxide (CO2) into green energy and valuable feedstocks through photocatalytic CO2 reduction (PCCR) offers a promising solution to global warming and energy needs. Among all semiconductors, zinc oxide (ZnO) has garnered considerable interest due to its ecofriendly nature, biocompatibility, abundance, exceptional semiconducting and optical properties, cost-effectiveness, easy synthesis, and durability. This review thoroughly discusses recent advances in mechanistic insights, fundamental principles, experimental parameters, and modulation of ZnO catalysts for direct PCCR to C1 products (methanol). Various ZnO modification techniques are explored, including atomic size regulation, synthesis strategies, morphology manipulation, doping with cocatalysts, defect engineering, incorporation of plasmonic metals, and single atom modulation to boost its photocatalytic performance. Additionally, the review highlights the importance of photoreactor design, reactor types, geometries, operating modes, and phases. Future research endeavors should prioritize the development of cost-effective catalyst immobilization methods for solid-liquid separation and catalyst recycling, while emphasizing the use of abundant and non-toxic materials to ensure environmental sustainability and economic viability. Finally, the review outlines key challenges and proposes novel directions for further enhancing ZnO-based photocatalytic CO2 conversion processes.

Synthesis and characterization of zinc oxide nanocomposite for fluoride ion removal from aqueous solution.

In India, the problem of fluorosis has arisen in semi-urban and rural areas due to the intake of groundwater. The development and application of zinc oxide nanocomposite recently received a lot of attention for fluoride ion removal. Nanotechnology and nanocomposites are widely used by researchers to treat wastewater and control water pollution. Rice husk is extensively found in rice-producing countries such as India that contributes about twenty-two percent of worldwide rice production. Rice husk is used to synthesize nanocellulose using chemical and mechanical approaches. To increase the effectiveness, nanocellulose was modified and coated with a zinc oxide layer to form nanocomposite by chemical precipitation method. Functional groups and morphological, structural, and surface area analysis were characterized by FTIR, FESEM, XRD, and BET. Results revealed that zinc oxide modification on nanocellulose was observed at 440.29 cm-1 and 616.94 cm-1. Maximum fluoride ion removal was achieved at varied initial ion concentrations 2 ppm (86%), 5 ppm (84%), 8 ppm (82%), 10 ppm (80%), 13 ppm (76%), and 15 ppm (75%) at pH 5 using 0.8 g/50 ml at 30°C in 60 min using zinc oxide nanocomposite in the batch study. The isotherm model's best-fitted order was Langmuir (R2=0.999) > Sips (R2=0.996) > Baudu (R2=0.993) > Fritz-Schluender (R2=0.992) > Freundlich (R2=0.986). A pseudo-second-order kinetic model (R2=0.989) fitted well with fluoride ion adsorption data showed chemical adsorption. The thermodynamic study showed the adsorption of fluoride ions due to physical adsorption.

Solution‐Processable Zinc Oxide for Printed Photovoltaics: Progress, Challenges, and Prospect

Zinc oxide (ZnO) is a promising candidate as the electron‐transporting layer of roll‐to‐roll printed organic and perovskite solar cells (OSCs and PVSCs) because it is low cost, nontoxic, earth‐abundant, and has multiple solution‐processable routes comparable. It has been widely used in both OSCs and PVSCs for many years. With the long‐time development of the ZnO buffer layer, various synthesis, fabrication, and modification approaches have been developed. Meanwhile, several issues including light‐soaking issues, defects issues, and agglomeration issues have emerged and have been solved. In this review, the synthesis approaches of solution‐processed zinc oxide, the application in the OSCs and the PVSCs, and the typical challenges of the solution‐processed ZnO for use in the OSCs and PVSCs have been summarized. Finally, an outlook on the development of solution‐processed ZnO for the upscaling of OSCs and PVSCs is given.

Modified-ZnO-mediated dye detoxification by a heterogeneous Fenton process

The continuous and unchecked discharge of effluents by the dyeing industry into water bodies has led to the rising importance of water treatment. This study focuses on the successful abatement of the auramine O (AM) dye in an aqueous system through a heterogeneous Fenton process using ultrasonication. Zinc oxide (ZnO) nanoparticles (NPs) were obtained by using a straightforward precipitation method and then modified with glycine (M-ZnO). The NP size sharply decreased upon modification with glycine. X-ray diffraction was used to determine the basic crystal properties, such as crystallinity. It was observed that the size of NPs sharply decreased from 24.6 nm (pure zinc oxide) to 17.3 nm upon modification of zinc oxide with glycine. A bandgap of 3.4 eV was determined for M-ZnO using a UV–visible spectrophotometer. Thermal gravimetric analysis revealed the excellent thermal stability of M-ZnO compared with that of zinc oxide. The catalytic activity for AM abatement was determined using a Fenton process at pH 6. Detoxification assays showed that pure hydrogen peroxide (H2O2) and pure zinc oxide exhibited 38 and 37% AM dye degradation, respectively. Meanwhile, M-ZnO showed 97% AM dye degradation in 240 min. A plausible mechanism is proposed for AM abatement using zinc oxide.

Biosynthesis of zinc oxide and silver/zinc oxide nanoparticles from Urginea epigea for antibacterial and antioxidant applications

Zinc oxide (ZnO) and silver-zinc oxide (Ag/ZnO) nanocomposite were synthesized by a green method using Zn(CH3COO)2 and AgNO3 as precursors for zinc and silver respectively; and Urginea epigea bulb extract as a reducing/capping agent. The nanomaterials were characterized by X-ray diffraction (XRD) analysis, Fourier transform infrared spectrophotometer (FTIR), ultraviolet-visible spectrophotometer, scanning, and transmission electron microscopy (SEM and TEM). Their elemental composition was studied using EDX analysis, while elementary mapping was used to show the distribution of the constituent elements. The powder X-ray diffraction confirmed hexagonal phase ZnO, while the Ag/ZnO nanocomposites identified additional planes due to cubic phase Ag nanoparticles. The absorption spectrum of the nanocomposite indicated a red shifting of the absorption band of the metallic ZnO and a surface plasmon resonance (SPR) band's appearance in the visible region due to the metallic Ag nanoparticles. The analysis from the TEM image showed the particles were of spherical morphology with a mean size of 35 nm (ZnO) and 33.50 nm (Ag/ZnO). The biological activity of the nanoparticles was studied for their antibacterial and antioxidant capacity so as to assess their ability to hinder bacterial growth and capture radical species respectively. The results demonstrated that the modification of ZnO with silver nanoparticles enhanced the antibacterial potency but reduced the antioxidant activity. This biogenic method offers a facile approach to nanoparticles for biological purposes, and the strategy may be extended to other metal oxide and their composites with metallic silver nanoparticles as a more effective approach compared to the physical and chemical routes.

Improving the Efficiency of Organic Solar Cells with Methionine as Electron Transport Layer.

Interface modification is an important way to get better performance from organic solar cells (OSCs). A natural biomolecular material methionine was successfully applied as the electron transport layer (ETL) to the inverted OSCs in this work. A series of optical, morphological, and electrical characterizations of thin films and devices were used to analyze the surface modification effects of methionine on zinc oxide (ZnO). The analysis results show that the surface modification of ZnO with methionine can cause significantly reduced surface defects for ZnO, optimized surface morphology of ZnO, improved compatibility between ETL and the active layer, better-matched energy levels between ETL and the acceptor, reduced interface resistance, reduced charge recombination, and enhanced charge transport and collection. The power conversion efficiency (PCE) of OSCs based on PM6:BTP-ec9 was improved to 15.34% from 14.25% by modifying ZnO with methionine. This work shows the great application potential of natural biomolecule methionine in OSCs.

Novel bionanocomposite of polycaprolactone reinforced with steam-exploded microfibrillated cellulose modified with ZnO

Polycaprolactone (PCL) bionanocomposites reinforced with microfibrillated cellulose (MFC), either plain or modified with 2 wt% of zinc oxide (ZnO) nanoparticles, were first time developed for possible application as multifunctional packing. The MFC was obtained by an alkali treatment, a steam explosion process, and ZnO modification applied to parchment (PAR), a husk waste from the coffee industry. X-ray diffraction (XDR), thermogravimetric analysis (TGA/DTG), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), tensile tests, and CO2 permeability characterized the MFCs and the bionanocomposites. As for the MCFs, the crystallinity index of 50.6% measured by XRD for the plain PAR fiber increases with the combined alkaline treatment and steam explosion (CFA/EXP) to 68.2%, and further with ZnO modification (ZnO-CFA/EXP) to 80.1%. TGA/DTG displays a rising onset of thermal degradation from 214 to 306 °C, as well as maximum degradation rate from 330 to 350 °C, for PAR and ZnO-CFA/EXP, respectively. Regarding the nanocomposites, the addition of 3 wt% of alkali/steam explosion and ZnO-modified CFA/EXP contributes to enhancing thermal stability. Tensile tests disclosed improved mechanical properties of the novel nanocomposites as compared to the PCL matrix. In particular, Young's modulus rose from 88.5 to 169.5 MPa for the plain PCL and PCL reinforced with 3(ZnO-CFA/EXP), respectively. SEM images evidenced the participation of cellulose micro and nanofibrils in the PCL matrix. Approximately 20% reduction in the CO2 permeability coefficient of both PCL and its 3CFA/EXP nanocomposite compared with 3(ZnO-CFA/EXP) proved that the ZnO nanoparticles provide a gas barrier to the nanocomposite, a convenient property for food packing.

Facile preparation PCL/ modified nano ZnO organic-inorganic composite and its application in antibacterial materials

Due to its good biodegradability and biocompatibility, polycaprolactone (PCL) has attracted widespread attention in the field of biomedical materials. Incorporation of Zinc oxide (ZnO) into PCL has been proved an effective way to improve its antibacterial properties. However, the interfacial compatibility of the organic-inorganic system needs to be improved due to the agglomeration of nanoparticles and phase separation of ZnO and PCL matrix affect its antibacterial efficiency. In this research, the ZnO surface was modified with citric acid monohydrate (CA) to improve the interfacial properties of ZnO-PCL system. The surface modification of ZnO was analyzed by DLS, TEM, TGA, and XPS. The results suggest that CA coating process can significantly reduce the agglomeration of ZnO nanoparticles and improve dispersion stability. The uniform PCL/ZnO-CA membranes with various nanofiller contents were fabricated through the solvent casting method. DSC and TGA analysis showed that the presence of ZnO-CA nanoparticles slightly decreased the crystallinity and thermal stability of the polymer. And ZnO-CA loaded improved the mechanical properties and wettability of the composite PCL membranes. Moreover, the composite PCL membranes showed good antibacterial activity against both E. coli and S. aureus while exhibiting good cytocompatibility, which indicated that the antibacterial and no cytotoxicity biomaterials had promising application in the biomedical field.

Raman spectroscopy of zinc oxide nanoplatelets modified with ruthenium (II) complexes

AbstractWe analyzed and compared the unmodified and three modified zinc oxide nanoplatelet materials. The three components used in zinc oxide modification were the 4,4apos;‐bipyridine and two ruthenium (II) complexes, namely, the trans‐[Ru (bpy)(bpyCOO)Cl2]2– and cis‐[Ru (bpy)(bpyCOO)Cl2]2–. The obtained results revealed that after modification, ZnO nanoplatelets became smaller and embedded in the materials used for the modification. When ZnO was modified with either of the two ruthenium (II) complexes, the interaction between them led to a higher activity of ZnO. The metal‐to‐ligand charge transfer that was also detected in the two cases of ZnO nanoplatelets modified with the ruthenium (II) complexes caused significant alteration of the Raman spectrum and consequent changes of the optical properties. Various forms of ruthenium (II) complexes were used in several published studies related to dye‐sensitized solar cells and biomedicine. The biomedical applications include, for example, the ATP (adenosine‐5apos;‐triphosphate) detection, interaction with human serum albumin, DNA analysis, and cancer detection and treatment. The properties of the ZnO nanoplatelets modified with the two ruthenium (II) complexes presented here indicate that it may be worth exploring if the studied materials are applicable in the dye sensitized solar cells and biomedicine. Possible advantage of our results is that they were obtained at room temperature.

Surface Modification of Zinc Oxide by 3-aminopropyltiethoxysilane and a Comparative Study of Effect of Corrosion on Carbon Steel With Epoxy Containing Graphene Oxide-Zinc Oxide (GO-ZnO) Hybrids

The use of coupling agent, 3-aminopropyltiethoxysilane (APTES) in the silanization reaction with metal oxides plays an important role to ensure that additional chemical modification can successfully be achieved. Studies have shown that introducing metal oxides onto graphene oxide sheets can improve the dispersion of sheets in a polymeric matrix, contributing to its excellent anti-corrosion properties. Hence, two methods of APTES attachment has been explored, where the first method utilizes a reflux process to introduce siloxane bonds to the ZnO NP surface; the latter usesuse of ultrasonication to stimulate the functionalization of ZnO NPs. Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS) were employed to characterize the APTES-Functionalized ZnO and the precipitation on the surface of GO sheets. The effect of GO-ZnO produced by the different types of functionalized ZnO on the corrosion protection and barrier performance of epoxy coating was investigated by electrochemical impedence spectroscopy (EIS). The results revealed that the long duration of reaction time provided by the reflux method managed to increase the number of siloxane bonds on the ZnO surface, allowing more amine groups to be attached onto the GO sheets and thus improve the corrosion resistance of epoxy.

Interface engineering for enhancement in performance of organic/inorganic hybrid heterojunction diode

Interface engineering through self-assembled monolayer (SAM) is an efficient way for tailoring the work function and electronic property of surface; enhancing the charge injection efficiency and device performance for microelectronics applications. Despite this, there is lack of study on effect of interface engineering of organic/inorganic hybrid heterojunction diode through SAM. Here, we have reported the surface engineering for tailoring the surface work function, electronic property, enhancement in injection efficiency and device performance. Therefore, Zinc Oxide (ZnO) film surface was modified with SAM before formation of hybrid ZnO/poly(3-hexylthiophene) (P3HT) heterojunction diode and compared with unmodified ZnO/P3HT diode. Prior to measurement of J-V heterojunction characteristics, both interfaces were characterized using absorption spectra, grazing incidence X-ray diffraction (GIXD), scanning electron microscopy (SEM), atomic force microscopy (AFM), kelvin probe force microscopy (KPFM). The modification of ZnO with SAM prior to heterojunction formation allows the better fabrication of diodes featuring ∼10 fold enhancement in rectification ratio at ±3 V and ∼32 fold enhancement in forward current density at 3 V with advancement in electronic device parameter. The enhancement in electrical characteristics are also discussed taking into account the absorption spectra, structural analysis, surface morphology, topography, surface potential, barrier height, and the energy band diagram of SAM's modified and unmodified diodes. Our study has cemented a path to further improve the device performance and parameter for electronic applications.

Development of multifunctional self-cleaning and UV blocking cotton fabric with modification of photoactive ZnO coating via microwave method

Abstract A new self-cleaning cotton fabric coated with zinc oxide (ZnO) was obtained via a facile and effective microwave method. The solution pH was a key factor in determining the morphology of ZnO crystal growth on the cotton fibers: rod structures were apt to be formed at pH 4–5, whereas flake and flower-like structures were preferentially formed at higher solution pHs of 6–7 and 10–11, respectively. It is proved that the photocatalytic and wettability performances of ZnO could be efficiently transferred to cotton fabric, leading to a preeminent UV-blocking and self-cleaning cotton fabric. The identified UV protection factors (UPFs) indicate the excellent UV-blocking properties of the ZnO-coated textile fabric synthesized at pH 6–7, 8–9 and 10–11 with UPFs of 222.52, 162.68 and 202.57, respectively. The ZnO coating layer on the cotton fabric significantly improved the wetting behavior of the fabric, such as water absorption speed, thereby affording a self-cleaning ability for the ZnO-coated cotton fabrics. This ability was checked according to the removal degree of coffee stain under UV irradiation at different humidities (30–90% RH). The coffee stains on the ZnO-coated cotton fabrics were almost removed after 15 h without needing any water or detergent and the highest removal effect was observed at 90% humidity.

Improvement in degradability of 58s glass scaffolds by ZnO and β-TCP modification

ABSTRACT58s bioactive glass shows great potential for bone defects repair. However, at early repairing stage, the degradation rate of 58s glass is too fast due to the fast ion-exchange. At later repairing stage, the degradation rate of 58s glass is too slow due to the high dense mineral layer. In this work, Zinc oxide (ZnO) and β-tricalcium phosphate (β-TCP) were introduced into 58s glass bone scaffolds to improve the degradability. The results showed that ZnO could decrease the degradation rate and promote the stability of 58s glass at early repairing stage. Moreover, the presence of β-TCP appeared to increase the degradation rate at a later stage of repairing. Furthermore, in vitro biocompatibility study, carried out using human osteoblast-like cells (MG63), demonstrated that ZnO and β-TCP enhanced cell attachment and proliferation. The study provided a reference for further research in bone tissue engineering.

ChemInform Abstract: Surface Structure Modification of ZnO and the Impact on Electronic Properties

AbstractReview: 232 refs.

Surface Structure Modification of ZnO and the Impact on Electronic Properties.

Zinc oxide (ZnO) is a widely utilized, versatile material implemented in a diverse range of technological applications, particularly in optoelectronic devices, where its inherent transparency, tunable electronic properties, and accessible nanostructures can be combined to confer superior device properties. ZnO is a complex material with a rich and intricate defect chemistry, and its properties can be extremely sensitive to processing methods and conditions; consequently, surface modification of ZnO using both inorganic and organic species has been explored to control and regulate its surface properties, particularly at heterointerfaces in electronic devices. Here, the properties of ZnO are described in detail, particularly its surface chemistry, along with the role of defects in governing its electronic properties, and methods employed to modulate the behavior of as-grown ZnO. An outline is also given on how the native and modified oxide interact with molecular materials. To illustrate the diverse range of surface modification methods and their subsequent influence on electronic properties, a comprehensive review of the modification of ZnO surfaces at molecular interfaces in hybrid photovoltaic (hPV) and organic photovoltaic (OPV) devices is presented. This is a case study rather than a progress report, aiming to highlight the progress made toward controlling and altering the surface properties of ZnO, and to bring attention to the ways in which this may be achieved by using various interfacial modifiers (IMs).

Influence of surface modification of zinc oxide nanoparticles on thermal behavior and hydrophilic property of PET–PEG composites

Zinc oxide (ZnO) nanoparticles were successfully prepared by a one‐step precipitation reaction in an aqueous solution of zinc acetate and sodium hydroxide with stearic acid (SA) as the modifying agent. Hydrophilic composites of poly(ethylene terephthalate) (PET), poly(ethylene glycol), and ZnO nanoparticles were prepared further by in situ polymerization. The surface modification of ZnO and the microstructure and properties of prepared nanoparticles were investigated by relative contact angle measurements (CA), Fourier transform infrared spectroscopy, X‐ray diffraction (XRD), scanning electron microscopy, and thermogravimetric analysis (TGA). Measurements of CA and XRD indicated that the surface‐treated ZnO was hydrophobic and had a significant improvement in crystallinity with SA. Compared with the nanocomposites filled with the pure ZnO, the modified ZnO exhibits a better dispersion in PET–PEG matrix. TGA results showed that the presence of modified ZnO nanoparticles can improve the thermal stability of PET–PEG matrix. CA and low field nuclear magnetic resonance methods were used to investigate the hydrophilic behavior of nanocomposites. The results revealed that modified nanoparticles had a positive effect on the bound water absorption. A simple model for the interactions between ZnO, SA, and PET–PEG matrix was proposed. POLYM. COMPOS., 37:1830–1838, 2016. © 2015 Society of Plastics Engineers

In situ synthesis of ZnO/ZnTe common cation heterostructure and its visible-light photocatalytic reduction of CO2 into CH4

The development of hierarchical superstructures and their application for the sake of clean and sustainable energy is an attractive research field. Here we reported in situ synthesis of common cation heterostructure via modification of zinc oxide (ZnO) by zinc telluride (ZnTe) photocatalyst through one-pot hydrothermal approach at reaction temperature of 180°C. The phase, crystal structure, morphology, composition, optical property and alignment of energy levels of the as-synthesized ZnO/ZnTe heterostructure have been thoroughly studied by different techniques. The heterostructure fabricated with different ZnO flower-like nanostructures (hundreds of nanometers for the rod length or sheet size of the petals and tens of nanometers for the corresponding diameter or thickness) exhibited different photocatalytic capability for reduction of carbon dioxide into methane under visible-light irradiation (λ≥420nm), which is mainly due to the different exposed crystal planes of ZnO and different surface area (15.0 and 5.6m2g−1 for sheet-like petals and rod-like petals, respectively). The obtained photocatalytic systems show good visible-light photoreduction capability even with ∼3.35% ZnTe in terms of atomic percentage, for which the solar energy conversion efficiency can reach ∼3.28% in the first 30min of photoreduction. The formation of heterojunction can facilitate charge transfer and thus improve the photocatalytic activity. In addition, the advantage of sharing common cations for a heterostructure is also briefly discussed.

Exploitation of zinc oxide impregnated chitosan beads for the photocatalytic decolorization of an azo dye

Investigations were made to evaluate and distinguish the photocatalytic decolorization of Reactive Red 2 (RR) dye using zinc oxide (ZnO) and zinc oxide impregnated chitosan beads (ZCB) under UV and visible light irradiations. To enhance the photoresponse of ZnO toward visible light, the modification of ZnO using biopolymer, chitosan, has been carried out and synthesized the ZCB. Both ZnO and ZCB photocatalysts were characterized by Fourier transform-infrared spectra (FT-IR), scanning electron microscopy (SEM), energy dispersive x-ray analysis (EDAX), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and diffuse reflectance spectra (DRS). Experiments were conducted to optimize various parameters, viz., irradiation time, the amount of catalyst, pH, co-ions and initial concentration of dye under UV and visible light irradiations. The percentage of decolorization of RR dye using ZnO and ZCB under UV as well as visible light is in the order of ZnO/UV>ZCB/vis>ZnO/vis>ZCB/UV. The mineralization/detoxification of RR dye was assessed by measuring chemical oxygen demand (COD) at optimized conditions. The kinetic studies demonstrated that the photocatalytic reactions followed the pseudo-first-order model. The reusability of as-synthesized ZCB was assessed.

Modified and Unmodified Zinc Oxide as Coagent in Elastomer Compounds

Abstract The aim of this work was to study the activity of unmodified and modified ZnO in the peroxide crosslinking of hydrogenated acrylonitrile-butadiene elastomer (HNBR) and ethylene-propylene copolymer (EPM). In the first step, zinc oxide was obtained by emulsion precipitation. Maleic acid was introduced onto the surface of ZnO using an in situ method. The unmodified and modified zinc oxide was characterized using dispersive and morphological analysis, BET surface area analysis, and elemental, spectroscopic and thermal analysis. In the second stage of the research, the ZnO/MA systems were incorporated into the structure of elastomer compounds improving the kinetic and mechanical properties of vulcanizates. The proposed modification method had a favorable effect on the physicochemical properties of the zinc oxide and on the kinetic and mechanical properties of the vulcanizates. This study demonstrated that modification of zinc oxide by maleic acid is a promising technique.

Photodegradation of Nitrobenzene Using Cobalt Modified Zinc Oxide Particles

This paper reports the synthesis and modification of zinc oxide, ZnO nanoparticles from zinc nitrate hexahydrate, citric acid and cobalt nitrate hexahydrate, using polyethylene glycol as a surfactant via a combination of hydrothermal and sol-gel methods. The sample was calcined at 500 °C for 2 h. The characterization of the nanoparticles was done using XRD, TEM, FESEM and BET surface area measurement analysis. The photodegradation study was run for 2 h in an improvised photoreactor using an 18 W visible light source. The extent of photodegradation and mineralization was conducted using UV-visible spectroscopy, COD and TOC measurements. The band gap energy was measured using UV-visible spectroscopy and it was found to be 3.22 eV. The XRD results confirmed the ZnO nanoparticles of being hexagonal with Wurtzite structure. The morphology as revealed by TEM and FESEM showed the samples to be spherical in shape and with particle size less than 100 nm. The surface area of the catalyst as measured via BET is 17.566 m2/g. After 2 h of degradation 80.39 % of nitrobenzene was removed. The COD and TOC results removal reach 79 and 66 %, respectively. From the results it could be understood that ZnO synthesized and modified using cobalt nitrate could be an effective candidate for wastewater treatment. - See more at: http://www.asianjournalofchemistry.co.in/user/journal/viewarticle.aspx?ArticleID=26_27_67#sthash.UcbNjrzp.dpuf