Wet Chemical Method Research Articles

Arc plasma‐deposited Co single‐atom catalysts supported on an aligned carbon nanofiber for hydrogen peroxide electrosynthesis and an electro‐Fenton process

AbstractAtomically dispersed single‐atom catalysts (SACs) on carbon supports show great promise for H2O2 electrosynthesis, but conventional wet chemistry methods using particulate carbon blacks in powder form have limited their potential as two‐electron (2e−) oxygen reduction reaction (ORR) catalysts. Here, we demonstrate high‐performance Co SACs supported on a free‐standing aligned carbon nanofiber (CNF) using electrospinning and arc plasma deposition (APD). Based on the surface oxidation treatment of aligned CNF and precise control of the deposition amount in a dry‐based APD process, we successfully form densely populated Co SACs on aligned CNF. Through experimental analyses and density functional theory calculations, we reveal that Co SAC has a Co–N2–O2 moiety with one epoxy group, leading to excellent 2e− ORR activity. Furthermore, the aligned CNF significantly improves mass transfer in flow cells compared to randomly oriented CNF, showing an overpotential reduction of 30 mV and a 1.3‐fold improvement (84.5%) in Faradaic efficiency, and finally achieves an outstanding production rate of 15.75 mol gcat−1 h−1 at 300 mA cm−2. The high‐performance Co SAC supported on well‐aligned CNF is also applied in an electro‐Fenton process, demonstrating rapid removal of methylene blue and bisphenol F due to its exceptional 2e− ORR activity.

Enhanced electrochemical performance of a cost-effective Sm2O3-coated spinel LiNi0.5Mn1.5O4 cathode for high-voltage lithium-ion batteries

Spinel LiNi0.5Mn1.5O4 (LNMO) has gained significant attention as a promising cathode material for lithium-ion batteries due to its high working voltage (>4.7 V) and energy density. However, challenges such as electrolyte decomposition-induced material interface erosion and transition metal dissolution under high operating voltage hinder its commercial use. In this study, a thin and uniform Sm2O3 layer has been successfully deposited on the surface of LNMO using a wet chemical method. A comprehensive investigation of surface morphology, crystal structure, and electrochemical performance of the modified LNMO is conducted. The results demonstrate that the Sm2O3 surface modification acts as a robust multifunctional protective layer, effectively shielding against hydrofluoric acid-induced chemical attack and enhancing the migration efficiency of lithium ions. Notably, the capacity retention rate of LNMO@Sm2O3 (3 wt%) remains up to 88 % after 280 cycles, significantly surpassing the uncoated counterpart. The coated material exhibits a capacity of 114 mAh g−1 even under 10 C rate conditions. Moreover, the AC impedance values and manganese dissolution of the modified material in the organic electrolyte are considerably lower than those of the uncoated counterpart. Theoretical calculations strongly support the experimental findings, revealing higher Mn vacancy formation energy and density of states at the Fermi energy level for the Sm2O3-modified electrodes. This research contributes to the field of surface modification and paves the way for further enhancements in the electrochemical performance of other high-voltage manganese-based lithium-ion batteries (LIBs).

MgO Modified by X2, HX, or Alkyl Halide (X = Cl, Br, or I) Catalytic Systems and Their Activity in Chemoselective Transfer Hydrogenation of Acrolein into Allyl Alcohol.

A new type of catalyst containing magnesium oxide modified with various modifiers ranging from bromine and iodine, to interhalogen compounds, hydrohalogenic acids, and alkyl halides have been prepared using chemical vapor deposition (CVD) and wet impregnation methods. The obtained systems were characterized using a number of methods: determination of the concentration of X- ions, surface area determination, powder X-ray diffraction (PXRD), surface acid-base strength measurements, TPD of probe molecules (acetonitrile, pivalonitrile, triethylamine, and n-butylamine), TPD-MS of reaction products of methyl iodide with MgO, and Fourier transform infrared spectroscopy (FTIR). The catalysts' activity and chemoselectivity during transfer hydrogenation from ethanol to acrolein to allyl alcohol was measured. A significant increase in the activity of modified MgO (up to 80% conversion) in the transfer hydrogenation of acrolein was found, while maintaining high chemoselectivity (>90%) to allyl alcohol. As a general conclusion, it was shown that the modification of MgO results in the suppression of strong basic sites of the oxide, with a simultaneous appearance of Brønsted acidic sites on its surface. Independently, extensive research on the reaction progress of thirty alkyl halides with MgO was also performed in order to determine its ability to neutralize chlorinated wastes.

Preparation and Electrochromic Properties of MnO2/PPy Composite Films with Coral-like Structures.

MnO2/polypyrrole (PPy) composite films were deposited on fluorine-doped tin oxide (FTO) conductive glasses by a two-step wet-chemical method, including electrochemical deposition and chemical bath deposition (CBD). The porous MnO2 films were first grown on FTO glasses by an electrodeposition method. Second, polypyrrole nanoparticles were polymerized by the oxidation-reduction reaction between MnO2 and pyrrole, using the presynthesized MnO2 as the skeleton. Then, MnO2/PPy composite films with coral-like structures were obtained. The electrochemical and electrochromic (EC) properties of the prepared films were investigated. The results show that, compared to the single MnO2 or PPy film, the MnO2/PPy composite film has a larger optical modulation (67.3% at a wavelength of 900 nm), faster response times (4 s for coloration and 3 s for bleaching), and a higher coloration efficiency (218.16 cm2·C-1). The high coloration efficiency attests to the exceptional performance of the composite film in converting electrical signals into vivid color changes. The electrochemical stability test results show that the composite film maintains a stable EC performance after 200 coloration/bleaching cycles. The coral-like structures of the composite film are responsible for the better EC properties.

Investigation on Deterioration of Allura Red Dye Under Visible Radiation by TiO2 Based Nanocomposite

This current study is to prepare and characterise a Cu-doped Titanium dioxide (TiO2) and Cu-doped Titanium dioxide with Tungsten (WO3) nanocomposite and its application for the deterioration of Allura Red (AR) Dye. After preparing the Cu- doped Titanium dioxide (TiO2) with WO3 and Cu-doped Titanium dioxide (TiO2) nanocomposites using wet chemical Sol-gel method over various soaking times, the XRD, BET, and Ultraviolet-visible spectroscopy were used to determine the properties of the synthesized Copper-doped Titanium dioxide and Copper-doped Titanium dioxide with Tungsten nanocomposites. When Tungsten was added to Cu-doped Titanium dioxide (TiO2), the X-Ray Diffraction showed that all of the composites' peaks shifted slightly in the direction of a higher diffraction angle. To evaluate surface area BET curve was used. The Copper-doped Titanium dioxide (TiO2)/Tungsten (WO3) nanocomposite gives a significant photocatalytic activity because of its increased surface area. High surface area (BET) and anatase phase development (XRD), which are the main contributors to effective photocatalytic activity, were identified by the work's results. XRD revealed that the synthesised materials were in the anatase phase. Compared to CDT, CTW-15, CTW-30, and CTW-60 nanocomposites, the surface area (BET) of the CTW-45 nanocomposite is larger at 128.79 m2/g. By examining the kinetics of reaction parameters such as dopant concentrations, pH, catalyst dose, and dye concentration, the catalysts were able to determine the ideal conditions for improved photocatalytic degradation of Allura Red dye. At pH 4, dye concentrations of 5 mg/L, and CTW-45 concentrations of 100 mg/L, the percentage of AR dye degradation was greater. The findings of this study can be used to develop efficient nanocomposites that remove Allura Red dye from wastewater.

Purification of Spherical Graphite as Anode for Li-Ion Battery: A Comparative Study on the Purifying Approaches.

Graphite is a versatile material used in various fields, particularly in the power source manufacturing industry. Nowadays, graphite holds a unique position in materials for anode electrodes in lithium-ion batteries. With a carbon content of over 99% being a requirement for graphite to serve as an electrode material, the graphite refinement process plays a pivotal role in the research and development of anode materials for lithium-ion batteries. This study used three different processes to purify spherical graphite through wet chemical methods. The spherical graphite after the purification processes was analysed for carbon content by using energy-dispersive X-ray (EDX) spectroscopy and was evaluated for structural and morphological characteristics through X-ray diffraction (XRD), scanning electron microscopy (SEM), and Brunauer-Emmett-Teller (BET) analyses. The analyses results indicate that the three-step process via H2SO4-NaOH-HCl cleaning can elevate the carbon content from 90% to above 99.9% while still maintaining the graphite structure and spherical morphology, thus enhancing the surface area of the material for anode application. Furthermore, the spherical graphite was studied for electrochemical properties when used as an anode for Li-ion batteries using cyclic voltammetry (CV) and galvanostatic charge-discharge (GCD) measurements. The results demonstrated that the purification process significantly improves the material's capacity with a specific capacity of 350 mAh/g compared to the 280 mAh/g capacity of the anode made of spherical graphite without purification.

Three-dimensional ordered CdS/ZnO porous nanostructures for high-performance photoelectrochemical water splitting

Three-dimensional ordered porous nanostructures have been considered as a key factor in developing high-performance photoelectrodes for photoelectrochemical (PEC) water splitting applications due to their high light absorption capacity and large surface area. In this study, the authors design and fabricate the three-dimensional ordered CdS/ZnO porous structures by the hard mould method. Firstly, polystyrene (PS) spheres were deposited on the indium tin oxide (ITO) conductive substrate; secondly, the gaps among the spheres were filled with ZnO material using electrochemical deposition; then the PS spheres were burned and formed the ordered porous structure of ZnO; finally, CdS nanoparticles were deposited on the surface of ZnO by wet chemical method to form a three-dimensional ordered CdS/ZnO porous structure.The photoelectrochemical water-splitting properties of the fabricated structures were studied and compared systematically. The results show that, under the irradiation of solar simulation, the efficiency of the optimised three-dimensional ordered CdS/ZnO porous structure is 3.4%, nearly 1.9 times higher than that of with 1.8% efficiency of thin-film CdS/ZnO structure at the same fabrication conditions.

Magneto-optical properties of superparamagnetic CoPt alloy nanoparticles in the UV–visible range

Superparamagnetic CoPt alloy nanoparticles were synthesized via a wet chemical method and exhibited intense magnetic circular dichroism (MCD) in the UV–visible range. The dissymmetry factor of MCD, gMCD, for the CoPt nanoparticles was 0.034 at room temperature in a magnetic field of ±1.6 T. The MCD responses may be due to plasmonic circular currents generated in the metallic CoPt nanoparticles by circularly polarized light. The responses were higher than those of the Co nanoparticles, likely due to the chemical stability and spin–orbit coupling.

Construction of visible-light-driven 2D/2D NiFe2O4/g-C3N4 Z-scheme heterojunction photocatalyst for effective degradation of organic pollutants and CO2 reduction

Developing photocatalytic systems with higher redox capability, large reactive surface area and enhanced charge separation are essential both from scientific and practical perspectives. To address both environmental and energy issues, herein, using a simple solvothermal and wet-chemical method, we designed a dimensionally matched Z-scheme NiFe2O4/g-C3N4 (NFO/CN) heterojunction to realize higher charge separation as confirmed from various physiochemical and electrochemical analysis. The optimized 6NFO/CN catalyst exhibited about 5.5, and 4.4-fold higher photocatalytic activity in the degradation of 2,4-dichlorophenol (2,4-DCP) and bisphenol A (BPA) pollutants respectively, in comparison to bare g-C3N4 nanosheets (CN). Further, the prepared samples also displayed 8.3-fold higher photoactivity for CO2 reduction to CO and CH4. The exceptionally improved visible-light activities were mainly attributed to the enormously enhanced charge separation through the construction of interfacial matching heterojunction for Z-scheme charge transfer. Moreover, the degradation of pollutants was primarily attributed to the involvement of superoxide radicals (•O2-). Hopefully, this study will provide a deep understanding to design g-C3N4-based dimensionally matched Z-scheme heterojunction photocatalysts for environmental remediation and solar fuel conversion.

Alpha nickel hydroxide electrodes improve aqueous rechargeable batteries capacity

Nickel hydroxide electrode materials have been improved for the use in Ni-based rechargeable batteries such as Ni-H2, NiMH, NiCd, NiFe, and NiZn batteries. A stabilized α-phase Ni1-xAlx(OH)2, synthesized using wet chemical coprecipitation methods while controlling pH accurately followed by hydrothermal treatments at 165 °C, is reported. Variations in synthetic routes, dopants and morphology had strong influence on the electrochemical performance. Morphological control, crystallinity and surface modification by Co(OH)2 were important for the better performance. Conventional battery grade β-Ni(OH)2 is usually made of a spherical particles, but we find that circular shaped particles can be advantageous. Hydrothermal treatments increase sample crystallinity and discharge capacity. A hydrothermal treated Ni0.8Al0.2(OH)2-LDH sample reaches a discharge capacity of 368 mAh g−1 and a corresponding Ni0.9Al0.1(OH)2 reaches 405 mAh g−1. Both have a circular-like morphology and the later shows a tap density of 1.52 g cm−3 and volumetric energy density of 531 mAh cm−3. Only a modest Co(OH)2 surface coating is needed to reduce the polarization behavior, increase the redox reaction reversibility and electrode kinetics via formation of CoOOH species after electrochemical oxidation.

High-Performance and Sensitive Humidity Sensors Based on Reduced Graphene Oxide/Nickel Ferrite Nanocomposites

This work reports the fabrication of highly sensitive humidity sensors using reduced graphene oxide (rGO), nickel ferrite nanoparticles (NiFe2O4 NPs), and their nanocomposites. rGO and NiFe2O4 NPs, obtained by the modified Hummers method and the wet chemical coprecipitation method, respectively, were used to synthesize rGO/NiFe2O4 nanocomposites at two different compositions. XRD analysis confirmed both the spinel structure of NiFe2O4 and the reinstatement of π-conjugated structure of graphene. Average crystallite sizes, calculated by XRD, were 17.80 nm, 13.60 nm, and 8.22 nm for NiFe2O4 NPs, rGO/NiFe2O4 (70/30), and rGO/NiFe2O4 (90/10), respectively. FTIR affirmed the successful reduction of graphene oxide to rGO. Optical bandgaps of 1.83 eV and 2.18 eV were obtained for rGO and NiFe2O4 respectively using Tauc plot. SEM confirmed the films’ porosity, providing more active sites for the adsorption of water molecules. Our results demonstrate that NiFe2O4 NPs show the highest response and sensitivity within the 35–90 RH% range. Additionally, the rGO/NiFe2O4 (70/30) nanocomposite achieved the fastest response/recovery time of 8/4 s at 100 Hz, with good repeatability and stability. These findings suggest that rGO/NiFe2O4 NCs are promising candidates for advanced humidity sensing applications due to their rapid response, sensitivity, and long-term reliability.

Comparison of the mass composition of Coconut Shell in TiO2 towards its characterization for supercapacitor applications

This study aims to evaluate the effect of the mass ratio on the capacitance of electrodes made from TiO2-based composites. The composites were synthesized using a wet chemical method and applied using the doctor blade technique, incorporating TiO2 and rGO derived from coconut shell activated carbon. Our findings reveal that at a 1:1 mass ratio, the atomic composition of Ti and O was non-uniform, although there was evident adherence of TiO2 elements to the sample surface. In contrast, at mass ratios of 1:3 and 1:5, a decrease in the concentration of Ti atoms and an increase in O atoms were observed, indicating a reduction in Ti oxidation. SEM analysis further revealed that particle size significantly impacts capacitance: smaller particle sizes yielded higher capacitance. In the 1:1 mass variation, the discharge process was protracted, taking up to 29.3 minutes and generating an electrical energy of 0.000413 joules with a capacitance of 489 μF. These insights are pivotal for optimizing the composition and mass ratio, fostering the development of electrode materials characterized by enhanced capacitance and energy efficiency. Such advancements hold promising potential for a range of applications in the energy storage sector.

Synthesize of bio-based encapsulated nano urea modified hydroxyapatite for controlling release of nitrogen and enhancing green bean yield

The massive rise in the world population requires increasing food production, and the world needs to decrease agricultural inputs like agrochemicals to preserve natural resources. The low nutrient use efficiency of conventional fertilizers has always been a concern because of their impact on the environment, and they are considered a waste of natural resources, which is against sustainability goals. Their low efficiency is attributed to their high solubility and fast release into the soil. Controlled-release fertilizers (CRFs) can reduce nutrient loss, which increases their efficiency and controls environmental pollution. In this study, single- and double-layers coating of biopolymers were applied to encapsulate nano urea-modified hydroxyapatite to control nitrogen release in soil. Hydroxyapatite was synthesized using the wet chemical precipitation method and two different rodlike and mesoporous hydroxyapatites were obtained. Nano-hydroxyapatite that had been synthesized was mixed with urea in two different amounts: 4:1 and 8:1. Biopolymers were then added on top. The current CRF synthesis strategy focuses on using low-cost, widespread biorefinery materials to decrease the manufacturing cost of CRFs. The nitrogen release rate of the synthesized CRFs and commercial urea in water and soil was studied. In field experiments, the impact of CRFs on green bean growth and yield was studied. The results showed that both single and double-coated CRFs reduced the N release rate in the soil and increased the fertilizer's longevity to 24 days, compared to 6 days for conventional urea. The total yield of green beans increased by 48%-120% by applying 75% of the recommended dose compared with that obtained with the full dose of conventional urea (control). Also, applying double-coated CRFs at N level of 25% of the recommended dose gives a green bean yield equal to the control. The recommended treatment is SC-CRF prepared with C-HA applied at N rate of 75% to match the future increase in the required amount of food.

Two‐dimensionalization of 3D perovskites for passive narrowband Photodetection

AbstractIn the rapidly advancing field of information technology, passive sensors with the exemption of external power input can serve as intelligent instruments for end‐node data acquisition. 3D perovskites have been recognized as a superior optoelectronic material but suffering from notorious instability due to their “soft lattice” nature. Replacing by their 2D counterparts in these photo‐sensing applications can boost the reliability level. However, traditional fabrication for 2D perovskite relay on wet chemistry methods, exhibiting complication, and inefficiency in making high‐quality films for device integration. This study unveils a new solid–solid conversion routing toward a direct transformation from 3D orientated films into 2D highly crystalline configuration, based on a spontaneous lattice regulation mechanism through an amine steam treatment. The resultant 2D film exhibits greater orientational micromorphology and a distinct monochromatic narrowband light sensing behavior after integration into a self‐powered photodetector. This method on perovskite conversion bears the promise of advanced future‐manufacturing for high‐performance photonic sensing.image

Surface engineering of P2-type cathode material targeting long-cycling and high-rate sodium-ion batteries

The widespread interest in layered P2-type Mn-based cathode materials for sodium-ion batteries (SIBs) stems from their cost-effectiveness and abundant resources. However, the inferior cycle stability and mediocre rate performance impede their further development in practical applications. Herein, we devised a wet chemical precipitation method to deposit an amorphous aluminum phosphate (AlPO4, denoted as AP) protective layer onto the surface of P2-type Na0.55Ni0.1Co0.1Mn0.8O2 (NCM@AP). The resulting NCM@5AP electrode, with a 5 wt% coating, exhibits extended cycle life (capacity retention of 78.4% after 200 cycles at 100 mA g−1) and superior rate performance (98 mA h g−1 at 500 mA g−1) compared to pristine NCM. Moreover, our investigation provides comprehensive insights into the phase stability and active Na+ ion kinetics in the NCM@5AP composite electrode, shedding light on the underlying mechanisms responsible for the enhanced performance observed in the coated electrode.

Rapid synthesis of PdCu nanosheets with enhanced electrocatalytic activity toward polyalcohol oxidation reaction

Reasonable design of Pd-based catalysts with specific composition and morphology is of great importance for promoting the commercial application.of direct alcohol fuel cells (DAFCs). Recently, two-dimension (2D) with high density of defects and massive low-coordinated surface atom has become research highlights in the field of catalysis. Herein, we report a wet chemical method for synthesizing PdCu nanosheets with abundant wrinkles. The ultrathin two-dimensional structure endows catalysts plentiful catalytic active sites and large specific surface area, improving atomic utilization efficiency. The formation of bimetallic PdCu alloy structure leads to the adjustment of Pd electronic structure, resulting in lattice compression effect. Benefitting from the structural and compositional characteristics, PdCu nanosheets (NSs) exhibits excellent electrocatalytic performance for ethylene glycol oxidation reaction (EGOR) and glycerol oxidation reaction (GOR) with the mass activity of 7031 mA mg−1/5117 mA mg−1, which is 4.4/3.9 times higher than that of commercial Pd/C catalysts. Furthermore, the remained mass activity of PdCu NSs is 3991/3851 mA mg−1 after the durability measurement for EGOR/GOR, which confirm PdCu NSs possesses superior stability. We believe that our synthetic strategy could provide robust reference for the development of high-performance eletrocatalysts.

Surface-to-bulk synergistic modification enables stable interface of Ni-rich oxide cathode for all-solid-state lithium batteries

All-solid-state lithium batteries (ASSLBs) are supposed to a highly forward-looking battery technology by reason of their conspicuous energy density and excellent safety. Ni-rich layered oxide cathodes have been extensively studied in ASSLB systems with sulfide electrolytes owing to their high voltage and preeminent specific capacity. However, the electrochemical performance of ASSLBs is severely degraded due to the interfacial physical contact failure, space charge layer effect, and chemical/electrochemical side reactions between sulfide electrolytes and Ni-rich oxide cathodes. In this work, the surface of LiNi0.92Co0.04Mn0.04O2 (NCM92) is coated with a nano-level CeO2 buffer layer and is simultaneously doped with Ce element (NCM92–1%Ce) by one-step wet chemical method. Ce doping is beneficial for maintaining structural stability and suppressing irreversible phase transition. The CeO2 buffer layer can efficaciously avoid the oxidation and decomposition phenomenon at the interface between NCM92 and sulfide electrolyte. As expected, NCM92–1%Ce cathode shows the discharge specific capacity of 141.46 mAh g−1 after 80 cycles at 0.2C with 79.32% capacity retention rate, which is much higher than that of the unmodified NCM92 cathode. The results indicate that the surface-to-bulk synergistic modification strategy can successfully improve the structure toughness and interface stability of Ni-rich oxide cathode for ASSLBs with sulfide electrolytes.

Continued development of a tool to measure intramuscular fat of Australian lamb carcases in commercial situations

Despite the importance of intramuscular fat (IMF) to eating quality, as yet no methodology has been widely adopted by the whole of industry in Australia to measure it routinely. Thus, a study was conducted to investigate the potential for a Near Infra-Red (NIR) device to predict the IMF content of the loin from spectra collected on the topside which is externally located on a hanging carcase and therefore easily accessible. To this end, NIR spectra were collected from topsides (m. semimembranosus) of 258 lamb carcases over 5 data collections and a sample of muscle was collected from the loin and the topside for IMF determination using a wet chemistry method. Subsequent Partial Least Square (PLS) models suggested the ability to predict the absolute IMF content of loins was poor (R2 = 0.28, RMSE = 1.26), yet there was a moderate ability to predict the IMF content of the topside (R2 = 0.56, RMSE = 0.82). Partial Least Square Discrimination Analysis (PLS-DA) models to classify cuts based on the IMF eating quality threshold of 4.5% yielded better predictive outcomes with accuracies of 66.7% and 76.7% for loin and topside respectively. However, further research to assess the relationship between the IMF of the loin and topside and reduce the impact of differences in overall absorbance between data collections will improve predictive outcomes.

Spiky Magnetic Microparticles Synthesized from Microrod-Stabilized Pickering Emulsion.

Tailoring the microstructure of magnetic microparticles is of vital importance for their applications. Spiky magnetic particles, such as those made from sunflower pollens, have shown promise in single cell treatment and biofilm removal. Synthetic methods that can replicate or extend the functionality of such spiky particles would be advantageous for their widespread utilization. In this work, a wet-chemical method is introduced for spiky magnetic particles that are templated from microrod-stabilized Pickering emulsions. The spiky morphology is generated by the upright attachment of silica microrods at the oil-water interface of oil droplets. Spiky magnetic microparticles with control over the length of the spikes are obtained by dispersing hydrophobic magnetic nanoparticles in the oil phase and photopolymerizing the monomer. The spiky morphology dramatically enhances colloidal stability of these particles in high ionic strength solutions and physiologic media such as human saliva and saline-based biofilm suspension. To demonstrate their utility, the spiky magnetic particles are applied for magnetically controlled removal of oral biofilms and retrieval of bacteria for diagnostic sampling. This method expands the toolbox for engineering microparticle morphology and could promote the fabrication of functional magnetic microrobots.

Bicone nanoflower evolution and multi-peak emission of polymer caped Cu doped ZnO.

A low-temperature polymer-assisted wet chemical method was used to synthesise Cu-doped ZnO bicone nanoflowers at three different PEG concentrations.The effects of PEG concentration on the structural, morphological and optical properties of Cu doped ZnO nanostructures were studied. X-ray diffraction studies revealed that the as-synthesized ZnO nanostructures are highly crystalline with a hexagonal wurtzite phase. The scanning electron microscopy (SEM) analysis showed that the prepared nanostructures have bicone-nanoflower morphology and PEG concentration has strongly influenced the size as well the shape of nanoflowers. The surface passivation effect of PEG on the band gap energies was studied by analysing UV -visible spectra of all the samples. The room-temperature fluorescent spectra of all the nanoflowers showed multiple peak emissions, both in the ultra-violet and visible regions, with varying intensities.These recasted multiple peaks are attributed to the morphological modification caused by the PEG addition.&#xD.