Zinc Nitrate Solution Research Articles

A concentrated electrolyte for zinc hexacyanoferrate electrodes in aqueous rechargeable zinc-ion batteries

In this study, a concentrated electrolyte was applied in an aqueous rechargeable zinc-ion battery system with a zinc hexacyanoferrate (ZnHCF) electrode to improve the electrochemical performance by changing the hydration number of the zinc ions. To optimize the active material, ZnHCF was synthesized using aqueous solutions of zinc nitrate with three different concentrations. The synthesized materials exhibited some differences in structure, crystallinity, and particle size, as observed by X-ray diffraction and scanning electron microscopy. Subsequently, these well-structured materials were applied in electrochemical tests. A more than two-fold improvement in the charge/discharge capacities was observed when the concentrated electrolyte was used instead of the dilute electrolyte. Additionally, the cycling performance observed in the concentrated electrolyte was superior to that in the dilute electrolyte. This improvement in the electrochemical performance may result from a decrease in the hydration number of the zinc ions in the concentrated electrolyte.

Effect of Supplementation of Nano Zinc on Rumen Fermentation and Fiber Degradability in Goats

A study was conducted to evaluate the efficiency of nano-zinc as a feed supplement on rumen fermentation and nutrient digestibility in goats (Capra hircus). Nano-sized zinc was synthesized by using 0.45M aqueous solution of zinc nitrate and 0.9M aqueous solution of sodium hydroxide as a salt of ZnO in nano form (NZnO). The particle size thus obtained was 74 nm and later it was confirmed to be zinc by using TEM-EDAX. Twenty-four male goats were divided in four groups on the basis of BW and were supplemented with either a basal diet with concentrate and straw at 50: 50 ratio (Control) alone or supplemented with 50 ppm zinc from inorganic ZnO (IZn-50), 50 ppm zinc from NZnO (NZn-50) or 25 ppm zinc from NZnO (NZn-25). The digestibility of DM, OM, CP, EE, total carbohydrates, and nutritive value of the diets in terms of DCP, TDN (%) and ME (Mcal/kg) did not vary (P>0.05) among treatment groups. The ADF and cellulose digestibility was significantly higher (P<0.05) in all three zinc supplemented groups than control. Supplementation of graded doses of NZn did not alter the individual and total ruminal VFA profile in goats, but the soluble zinc content in the rumen liquor was higher in NZn-50 than NZn-25 and control. The rumen pH and protozoa count was higher in NZn-50 than control, IZn-50, and NZn-25. Nano Zn at 50 mg/kg DM altered the rumen pH, total protozoa count, fibre degradation and soluble zinc content in goats without affecting the individual and total VFA profile. It is concluded that nano Zn can be supplemented at half the dose of inorganic Zn without affecting rumen VFA profile, rumen soluble Zn content in goats.

Controlled Electrodeposition of Zinc Oxide on Conductive Meshes and Foams Enabling Its Use as Secondary Anode

Both compact and porous zinc oxide (ZnO) films were electrochemically deposited out of aqueous zinc nitrate solutions under pulsed galvanostatic control onto different three-dimensional (3D) substrates. Gold and carbon meshes as well as copper and nickel foams were used as substrates, all having complex geometries in micrometer dimensions with high surface area. Electrodepositions of ZnO were controlled by regulating the most relevant parameters: the applied current density, the total deposition time, and the length of current pulses and pauses to avoid gas evolution interfering with film growth at the electrodes. Optimization of these parameters for each of the substrates allowed deposition of homogeneous ZnO films of the desired total film thickness. Potential-time curves measured during deposition helped to monitor film growth. Scanning electron microscopy (SEM) micrographs showed that pinhole-free ZnO films were deposited uniformly in a 3D manner on all substrates. X-ray diffraction (XRD) measurements confirmed the formation of highly crystalline ZnO films. Such electrodeposited ZnO films on electronic conductive substrates with high surface area are promising for application in energy storage and conversion systems – especially for secondary batteries with zinc anodes which was shown by cyclic voltammetry (CV).

Meeting of Galvanic Cell and Smart Window

전지의 시초라고 볼 수 있는 galvanic cell과 현대의 최첨단 기술인 smart window와의 만남을 목적으로 하는 실험을 진행하였다. 이탈리아의 해부학자인 Galvani는 개구리 해부실험 중 목격한 근육수축 현상으로 전기발생 장치를 제작하려 했으나 실패하였고, 물리학자인 Volta는 다른 관점에서 기전력을 이용한 최초의 전지를 고안했다. 본 실험에서는 구리전극과 질산구리 수용액, 아연전극과 질산아연 수용액을 이용한 galvanic cell을 만들었다. Smart window는 인듐이 주입된 주석산화물(In-SnO2)의 전도성 유리를 기판으로 사용하여 회전코팅(spin-coating)법으로 이산화티타늄(TiO2) 현탄액을 코팅하고 두 개의 전극을 샌드위칭(sandwiching)하여 전극 사이에 전해질 용액을 투입해서 만들었다. 제작한 galvanic cell과 smart window를 연결하여 변색되는 현상을 관찰하였다.The meeting of galvanic cell, which is considered to be the beginning of the battery, and smart window, which is the cutting-edge technology of the modern age, was conducted to meet the classical technology and the modern technology. Luigi Galvani, an Italian physician, physiologist and physicist, invented a galvanic cell as a phenomenon during frog anatomy experiments. In this experiment, a galvanic cell was made using a copper electrode, a solution of copper nitrate, a zinc electrode and a zinc nitrate solution. In the smart window, titanium dioxide (TiO2) as a thin film was coated by a spin-coating method using a conductive glass of tin oxide (SnO2) doped with indium ions as a substrate, as sandwiched between two glasses. We observed the discoloration phenomenon by connecting the smart window with the galvanic cell that we made directly.

Characterization of mixing performance in a microreactor and its application to the synthesis of porous coordination polymer particles

Here we quantitatively evaluated the mixing performance of a tailor-made microreactor with central-collision type through the iodide/iodate chemical test reaction, and applied the microreactor to the synthesis of zeolitic imidazolate framework-8 (ZIF-8), which is a subclass of porous coordination polymers (PCPs) or metal organic frameworks (MOFs). The chemical test reaction demonstrated excellent mixing performance of the microreactor with a characteristic mixing time shorter than 1ms, which is approximately 100 times faster than those of a batch reactor and a millimeter-sized Y-shaped mixer. Taking advantage of the rapid and uniform mixing, the microreactor successfully produced ZIF-8 particles with high reproducibility by simply mixing aqueous solutions of zinc nitrate and 2-methylimidazole. The synthesis at room temperature resulted in ZIF-8 particles with chamfered cube shape, while a lower temperature of 5°C produced raspberry-type spherical particles. We confirmed that prepared ZIF-8 particles have BET surface area of ∼1500m2/g and exhibit the gate adsorption behavior caused by the structural transition of the ZIF-8 framework.

Synthesis of novel microporous nanocomposites of ZIF-8 on multiwalled carbon nanotubes for adsorptive removing benzoic acid from water

This study reports a controlled route for straightforward synthesizing novel microporous nanocomposites of ZIF-8 type metal–organic frameworks material incorporated with multiwalled carbon nanotubes (MWNTs). The prepared ZIF-8/MWNTs samples were characterized by XPS, XRD, SEM, TEM, N2 adsorption and TGA experiments to investigate the effects of synthesis methods on the formation of the hybrid composite structure of ZIF-8 nanocystals growing on MWNTs. The ZIF-8/MWNTs nanocomposites were successfully synthesized by the method of adding MWNTs into a zinc nitrate solution prior to react with a 2-methylimidazole solution and the microporous structures of the ZIF-8/MWNTs nanocomposites were controlled by the MWNTs content. As an adsorbent for adsorptive removing benzoic acid (BA) from water, the prepared ZIF-8/MWNTs-25 (B) nanocomposite exhibits the best adsorption capacity of 303mg/g, about 65mg/g higher than the ZIF-8. The improvement in the BA adsorption is due to the pore/size-selective BA adsorption of the effective micropores yielded by the ZIF-8/MWNTs hybrid composite structure, in addition to the basic-acid, coordination, and π–π stacking interactions between ZIF-8 and BA. The high adsorption capacity and good reusability of the ZIF-8/MWNTs-25 (B) nanocomposite suggests that it can be applied as novel adsorbents showing attractive potential.

A Fast and Scalable Approach for Synthesis of Hierarchical Porous Zeolitic Imidazolate Frameworks and One-Pot Encapsulation of Target Molecules.

A trimethylamine (TEA)-assisted synthesis approach that combines the preparation of hierarchical porous zeolitic imidazolate framework ZIF-8 nanoparticles and one-pot encapsulation of target molecules is presented. Two dye molecules, rhodamine B (RhB) and methylene blue (MB), and one protein (bovine serum albumin, BSA) were tested as the target molecules. The addition of TEA into the solution of zinc nitrate promoted the formation of ZnO nanocrystals, which rapidly transformed to ZIF-8 nanoparticles after the addition of the linker 2-methylimidazole (Hmim). Hierarchical porous dye@ZIF-8 nanoparticles with high crystallinity, large BET surface areas (1300-2500 m2/g), and large pore volumes (0.5-1.0 cm3/g) could be synthesized. The synthesis procedure was fast (down to 2 min) and scalable. The Hmim/Zn ratio could be greatly reduced (down to 2:1) compared to previously reported ones. The surface areas, and the mesopore size, structure, and density could be modified by changing the TEA or dye concentrations, or by postsynthetic treatment using reflux in methanol. This synthesis and one-pot encapsulation approach is simple and can be readily scaled up. The photophysical properties such as lifetime and photostability of the dyes could be tuned via encapsulation. The lifetimes of the encapsulated dyes were increased by 3-27-fold for RhB@ZIF-8 and by 20-fold for MB@ZIF-8, compared to those of the corresponding free dyes. The synthesis approach is general, which was successfully applied for encapsulation of protein BSA. It could also be extended for the synthesis of hierarchical porous cobalt-based ZIF (dye@ZIF-67).

Morphological and optical properties of ZnO thin films grown on Si and ITO glass substrates

In this study, ZnO thin films have been electrodeposited from zinc nitrate solution without using any catalyst, additive or seed layer on two kinds of substrates (Si and ITO glass).Using cyclic voltammetry and chronoamperometry, it was shown that the mechanism of ZnO deposition strongly depends on the substrate used and its overpotential for nitrate reduction. On Si, the nitrate reduction into nitrite occurs before that of Zn2+. This reaction induces an increase of the local pH leading to ZnO precipitation. In contrast on ITO, the Zn2+ reduction brings first metallic Zn deposition, which is then chemically oxidized by nitrate into ZnO phase. The effect of deposition time on morphology, structure and photoluminescence properties was studied using X-ray diffraction (XRD), scanning electron microscopy (SEM) and photoluminescence (PL) measurements.The chemical nature of the substrate has no influence on the orientation of nanorods, but really impacts their morphology and the optical emission properties. X-ray diffraction analysis always revealed ZnO wurtzite phase with a (002) preferential orientation enhanced with increasing deposition time. A well-defined ZnO morphology was generated under -1.4 V for 60 min on Si and ITO glass. ZnO nanorods that composed the nanoflowers grown on ITO glass tend to be shorter, wider, with higher aspect ratio than on Si. ZnO nanostructures prepared on ITO showed an intense UV emission without spreading in the visible region, thus demonstrating the formation of a defect free structure.

Synthesis, Crystal Structures, and Properties of Zeolite‐Like T3(H3O)2[M(CN)6]2·uH2O (T = Co, Zn; M = Ru, Os)

We report the synthesis, crystal structures, and related properties of six new zeolite‐like hexacyanometallates of formula unit T3(H3O)2[M(CN)6]2·uH2O (T = Co2+, Zn2+; M = RuII, OsII). Their crystal structures were solved and refined from their X‐ray powder diffraction patterns in combination with the IR and UV/Vis/NIR spectroscopic data. The Co and Zn ions are coordinated tetrahedrally to the N atoms of four CN groups. The deconvolution of the overlapped UV/Vis/NIR spectral bands provided conclusive evidence of the tetrahedral coordination of the Co atoms. These materials have porous frameworks, which are characterized by a 3D array of TN4tetrahedral units linked to the MC6octahedral blocks in a 3:2 ratio. From the IR spectroscopy results, we found that all of the compounds reported here contain hydronium countercations. Two different structures in the same space group (R3c) were identified for the Co‐based materials. However, only a single phase was found for the Zn‐containing compounds. Density functional theory (DFT) modeling predicts hydrogen bonds between the hydronium ions and the CN groups at the surfaces of the pores. These materials were prepared through the hydrothermal recrystallization of the solids obtained from mixing ethanol solutions of H4[M(CN)6] with aqueous solutions of cobalt(II) nitrate and zinc nitrate. Our results illustrate the potential of the hydrothermal recrystallization technique for the preparation of metal hexacyanometallates with new structures and pore topologies that are not obtainable by the traditional precipitation method.

Electrodeposition and characterization of ZnO thin films using sodium thiosulfate as an additive for photovoltaic solar cells**Project supported by the Algerian Ministry of Higher Education and Scientific Research, Algeria (No. J0101520090018).

Zinc oxide thin films have been grown by electrodeposition technique onto Cu and ITO-coated glass substrates from an aqueous zinc nitrate solution with addition of sodium thiosulfate at 90 °C. The effects of sodium thiosulfate on the electrochemical deposition of ZnO were investigated by cyclic voltammetry and chronoamperometry techniques. Deposited films were obtained at −0.60 V vs. SCE and characterized by XRD, SEM, FTIR, optical, photoelectrochemical and electrical measurements. Thickness of the deposited film was measured to be 357 nm. X-ray diffraction results indicated that the synthesized ZnO has a pure hexagonal wurtzite structure with a marked preferential orientation along (002) plane. FTIR results confirmed the presence of ZnO films at peak 558 cm−1. SEM images showed uniform, compact morphology without any cracks and films composed of large flower-like ZnO agglomerates with star-shape. Optical properties of ZnO reveal a high optical transmission () and high absorption coefficient ( in visible region. The optical energy band gap was found to be 3.28 eV. Photoelectrochemical measurements indicated that the ZnO films had n-type semiconductor conduction. Electrical properties of ZnO films showed a low electrical resistivity of , carrier concentration of and mobility of 7.35 cm2 V−1 s−1.

Synthesis and characterization of ZnO nanostructures with varying morphology

Uniform fine particles of zinc oxide were prepared in three different morphologies and sizes by the controlled precipitation process from aqueous solutions of zinc nitrate in the presence of ethylene glycol. Ammonium hydroxide solution was used as the precipitant. Composition of the reactant solution, pH and temperature significantly affected the particle uniformity with respect to shape and size. Uniformity in the particles morphological feature was achieved under a narrow set of experimental conditions. pH of the reactant solutions and isoelectric point of zinc oxide were considered the master variables, controlling the particle size. One of the batch of the as-prepared zinc oxide particles was calcined at \(750{^{\circ }}\hbox {C}\), which increased its crystallinity, changed its various lattice parameters, Zn–O bond length and preferred orientation of the crystal hkl planes. Calcination had little effect on the original morphology of the zinc oxide particles.

Photodegradation of Rhodamine B by using ZnFe2O4 Nanoparticles Synthesized through Precipitation Method

ZnFe2O4 nanoparticles were synthesized through precipitation method from the mixed aqueous solution of ferric nitrate and zinc nitrate. The precipitate was calcined at the temperature of 600, 700, and 800 °C for 3 hours to obtain crystalline nature. The effects of calcination temperature on the properties of ZnFe2O4 nanoparticles were investigated. The structure, morphology, and optical properties of ZnFe2O4 nanoparticles were characterized by using X-ray diffractometer (XRD), scanning electron microscope (SEM), and UV-vis spectrophotometer, respectively. The photocatalytic activity of ZnFe2O4 nanoparticles was examined to Rhodamine B degradation in water under UV irradiation. The results show that the calcination temperature influences on ZnFe2O4 phase, crystallite size, and the energy gap of ZnFe2O4 nanoparticles. ZnFe2O4 nanoparticles calcined at 700 °C shows the best photocatalytic activity to Rhodamine B degradation due to smaller crystallite size and higher absorption.

Properties of Semiconductors: Synthesis of Oriented ZnO for Photoelectrochemistry and Photoremediation

Semiconductors are an important class of materials; preparing ZnO nanorods allows semiconducting properties to be easily observed. The week before lab, groups of four students take 15 min to setup two fluorine-doped tin oxide glass (FTO) slides in a zinc nitrate and hexamethylenetetramine solution stored at 90 °C until the next lab. Hexagonal ZnO nanorods oriented along the c-axis are produced, as shown by X-ray diffraction (XRD) and scanning electron microscopy (SEM) images. Semiconductor properties are observed by measuring the band gap by UV–visible absorption spectroscopy and exposing samples to UV light to excite electrons into the conduction band. One pair of students obtains SEM and photoelectrochemical measurements, while the other pair obtains an absorption spectrum, XRD scan, and methylene blue kinetic data. The primary pedagogic goal of the experiment is to reinforce semiconductor concepts where two teams collaborate to summarize their evidence that ZnO is a semiconductor.

Single crystal X-ray structure of the artists' pigment zinc yellow

The artists' pigment zinc yellow is in general described as a complex potassium zinc chromate with the empirical formula 4ZnCrO4·K2O·3H2O. Even though the pigment has been in use since the second half of the 19th century also in large-scale industrial applications, the exact structure had hitherto been unknown. In this work, zinc yellow was synthesised by precipitation from an aqueous solution of zinc nitrate and potassium chromate under both neutral and basic conditions, and the products were compared with the pigment used in industrial paints. Analyses by Raman microscopy (MRS), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS), attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR), and powder X-ray diffraction (PXRD), showed that the synthesised products and the industrial pigment were identical. Single-crystal X-ray crystallography determined the structure of zinc yellow as KZn2(CrO4)2(H2O)(OH) or as KZn2(CrO4)2(H3O2) emphasizing the μ-H3O2− moiety. Notably, the zinc yellow is isostructural to the recently structurally characterized cadmium analog and both belong to the natrochalcite structure type.

Ultra-deep desulfurization via reactive adsorption on nickel and zinc species supported on activated carbon

The reactive adsorption desulfurization behavior of the Ni and Zn metal species supported on the activated carbon were investigated. The adsorbents were prepared by incipient wetness impregnation of the carbon support with aqueous solutions of nickel nitrate, zinc nitrate and nitrilotriacetic acid. The impregnated precursors transfer to ZnO and Ni3ZnC0.7 phase after calcination in nitrogen, and partially convert to NiZn alloy by hydrogen reduction treatment. The residual Ni3ZnC0.7 phase of the reduced adsorbents can be consumed slowly in the desulfurization process. The sulfur content of outflow oil can be readily decreased from original 640 ppmw to near zero residual sulfur with a breakthrough sulfur capacity of 106.5 mg-S/g-adsorbent, corresponding to 490 mg-S/g-(NiO + ZnO). The high efficiency of the adsorbents suggests that the release of metallic Ni from NiZn alloy is sufficiently rapid to provide an active phase for desulfurization and the formation of NiZn alloy is also favorable for the contact between Ni and Zn species which could accelerate the sulfur transfer from Ni3S2 to Zn phase.

Iodine-loaded metal organic framework as growth-triggered antimicrobial agent

Zeolitic imidazolate framework-8 (ZIF-8) is one of easily available metal organic frameworks because of its facile preparation via mixing aqueous solutions of zinc nitrate and 2-methylimidazole. It turned into a very effective pH-responsive bactericide after loading with iodine. Approximately, 0.9g of iodine could be readily loaded into one gram of ZIF-8 from iodine dissolved n-heptane solution. Both Gram-negative Escherichia coli and Gram-positive Staphylococcus epidermidis and Staphylococcus aureus could be very effectively killed by iodine loaded ZIF-8 (ZIF-8@I) at pH6.0 within 3min. In contrast, at pH above 7.0, no appreciable antimicrobial activity could be detected. The bacteria killing effect is resulted from the iodine released from ZIF-8@I disintegrated at acidic pH. ZIF-8@I coated surface also showed its acidic pH-triggered antimicrobial activity against deposited bacterial cells. The antimicrobial activity of ZIF-8@I against actively grown bacterial lawns on a pH neutral agar plate was also observed. The result demonstrates that iodine was released from the disintegrated ZIF-8@I to kill bacteria in response to the bacterial growth-induced pH lowering.

Synthesis and properties of geopolymers based on water treatment residue and their immobilization of some heavy metals

Inorganic polymers (geopolymers) were synthesized by alkali activation of water treatment residue, a waste material containing aluminosilicates and a significant concentration of iron in the form of a ferric nanoparticle oxide gel. The effect on the structures of these geopolymers of incorporating the heavy metals chromium, zinc and iron, as occur in industrial wastewaters, was studied by their addition at the geopolymer synthesis stage, both as the pre-prepared hydroxides and as 1 M nitrate solutions. The heavy metals form several new crystalline phases, but the geopolymers display typical solid-state 27Al and 29Si MAS NMR characteristics. The 28-day strengths of the geopolymers without the metals (up to 11.2 MPa) were significantly degraded by the presence of the heavy metals, particularly 1 M zinc nitrate solution. The deleterious effect of the heavy metals on the strength may arise from their presence as the hydroxides rather than their incorporation as charge-balancing cations in the geopolymer structure. Leaching tests in simulated acid rain indicate that the geopolymers with molar ratios of SiO2/Al2O3 = 1.78 are capable of immobilizing all three metals to within safe leachate levels. The geopolymers are sufficiently strong to withstand handling and transportation and are capable of immobilizing wastes containing these heavy metals for storage or disposal.

PHASE COMPOSITION, THERMAL BEHAVIOR AND MAGNETIC PROPERTIES OF ZINC- AND NICKEL-BEARING POWDERS FORMED ON THE STEEL SURFACE IN THE OPEN-AIR SYSTEM

The nanosized powders formed on the steel surface contacting with zinc and nickel inorganic water salt solutions have been studied using an X-ray diffraction method, thermal analytical measurements (TG/DTG, DTA,) scanning electron microscopy, and magnetometry. It was shown that the formation of a single mineral phase of a non-stoichiometric spinel ferrite when zinc and nickel nitrate solutions were used as the dispersion medium, but in the presence of chloride-containing salts three mineral phases (spinel ferrite, lepidocrocite, and goethite) were determined in the phase composition of the surface powders. When sulfate solutions were chosen as the dispersion medium the mixed hydroxysulfate layered double hydroxides (LDHs) simultaneously appeared among other components of the powders. Due to cation exchange between Fe 2+ and Zn 2+ or Ni 2+ the mixed LDH structures achieved stability against further oxidation and thermal transformation. Hence, the presence of mixed LDHs in the phase composition of the powders significantly complicates the obtaining of homogenous superparamagnetic 3 d -metal doped spinel ferrite and iron oxide powders.

Hydroxyapatite-based sorbents: elaboration, characterization and application for the removal of catechol from the aqueous phase

ABSTRACTHydroxyapatite (HAP) is highly considered as good sorbent for the removal of metals from the aqueous phase. However, soluble metals co-exist with organic pollutants in wastewaters. But little work has been devoted to investigate the reactivity of HAP for the removal of organic compounds. The main objective of this work is to study the reactivity of HAP-based sorbents for the removal of catechol as a model organic pollutant from an aqueous solution. Thus, HAP sorbents were firstly synthesized using calcium carbonate and potassium dihydrogen phosphate under moderate conditions (25–80°C, atmospheric pressure). A zinc-doped HAP was also used as sorbent, which was obtained from the contact of HAP with an aqueous solution of zinc nitrate. All the sorbents were characterized by different standard physico-chemical techniques. The sorption of catechol was carried out in a batch reactor under stirring at room temperature and pressure. Zinc-doped HAP sorbent was found to be more reactive than non-doped HAP sorbents for the fixation of catechol. The highest sorption capacity was of 15 mg of C per gram of zinc-doped HAP sorbent. The results obtained suggest the reaction scheme of HAP sorbents with metals and organic pollutants when HAP sorbents were used for the treatment of complex wastewaters.

Effect of pH on the properties of electrochemically prepared ZnO thin films

Zinc Oxide (ZnO) thin films have been electrochemically deposited on fluorine doped tin oxide (FTO) coated glass substrates from an aqueous electrolyte. Deposition potential −0.96V was optimized by cyclic voltammetry experiment for slow scan rate 5mV/s with moderate agitation of electrolyte. The effect of pH on the electrodeposition of ZnO is studied by cyclic voltammetry, X-ray diffraction (XRD), scanning electron microscopy (SEM), optical spectroscopy and photoelectrochemical I-t transient characteristics. It is revealed that the pH of the electrolyte has significant influence on the surface morphology and structural properties. Highly crystalline ZnO layers with hexagonal crystal structure deposited for all pH of the solutions. A systematic shift observed in the reflections (002) and (101) is correlated with an effective tensile strain developed in the crystal lattice. A remarkable improvement in the crystallinity was noticed in the as-deposited ZnO samples with increasing pH and upon heat treatment. Optical direct band gap ~ 3.26–3.33eV and transmittance ~70 −80% was measured by optical spectroscopy. PL measurement showed the band edge emission at 375–382nm and a visible light emission at 410–550nm. The intensities of emission peaks are found to be affected by the pH of bath. The compact, densely packed and well adherent thin films of ZnO electrodeposited in zinc nitrate bath for pH 2.0, 3.5 and 6.0. The surface morphology has been changed from granular to disc shaped and finally a large hexagonal sheets were obtained with an increase in the pH of bath. Nearly stoichiometric ZnO thin films are electrodeposited at −0.96V versus Ag/AgCl reference electrode for pH 6.0. The photoelectrochemical (PEC) measurement (I-t transient curve) shows the enhancement in photocurrent with increasing the pH of zinc nitrate solution. After heat treatment the photocurrent is increased by 54%, 98% and 130% in the samples deposited from 2.0, 3.5 and 6.0pH of the bath. I-V measurements were further confirmed the current enhancement in all samples after heat treatment.