Chemical Deposition Method Research Articles

Fabrication of Cellulose Capped MnxOy-Ag Nanocomposites and Investigation of Its Oxidative and Antibacterial Efficacy in Water Environment

The Mn3O4-Ag nanocomposite has a large specific surface area and a strong adsorbing and oxidizing reactivity due to the high reducing potential of the Mn3O4 phases it contains. The Mn3O4-Ag nanocomposites were synthesized by a simple chemical deposition method. The organic dye, methylene blue (MB), was found to be approximately 80% decolorized in about 1 min from their aqueous solution during the treatment of the dyes with a suspension of Mn3O4-Ag in an acidic medium and almost completely decolorized within 2 h. The creation of a surface precursor complex between MB and surface-bound Mn (II and III), where electron transferring occurs inside the surface complex, caused the decolorization of MB by Mn3O4-Ag. This nanocomposite also showed the antibacterial activity against Salmonella typhi and Bacillus megaterium, which cause typhoid disease and chronic brain abscesses, respectively.

Construction of hollow-sphere CuNi2S4 with optimized structure and boosting conductivity for hybrid supercapacitor

Transition bimetallic sulfides with optimal composition and structure are promising battery-type materials for hybrid supercapacitors. The structure and conductivity of bimetallic sulfides are improved compared to monometallic sulfides. Herein, bimetallic spinel sulfide CuNi2S4 is first synthesized via a two-step method of chemical deposition and subsequent solvothermal method. The molar ratio of the Ni:Cu elements, chemical deposition time, and solvothermal reaction temperature are critical factors for forming single-phase CuNi2S4. The formation of hollow-sphere morphology of CuNi2S4 can be ascribed to the Kirkendall effect. CuNi2S4 electrode performs ultrahigh capacity of 458.9 mAh g−1 at 1 A g−1 and remains 84.6% and 77.7% capacity after 5000 and 10,000 cycles with coulombic efficiency of >99% at 4 A g−1. Density Functional Theory (DFT) calculation results demonstrate that the electronic conductivity of CuNi2S4 is higher than Ni3S4. The favorable electrochemical performance of CuNi2S4-2 electrode can be ascribed to the hollow structure with a large active surface and decent conductivity. The synergistic effect between Ni and Cu elements also further enhances the capability of CuNi2S4. The hybrid supercapacitor with high mass loading of 59 mg cm−2 using CuNi2S4-2 as cathode and active carbon as anode obtains an energy density of 87.0 Wh kg−1 with a power density of 1048.8 W kg−1 and cyclic retention of 82.3% after 10,000 cycles. In combination, the superior electrochemical performance of spinel CuNi2S4 makes it a promising candidate for hybrid supercapacitors.

Thin Film Deposition and Characterization Techniques

Thin films are everywhere in the modern world, with many of the technologies we depend upon in daily life being, in turn, dependent upon thin film technology. Chemical bath deposition includes principles of chemical bath deposition (CBD) and concept of solubility product, nucleation and film growth, thin film deposition mechanism in chemical bath deposition. The non-metallic ion source (anions) and metal ion source (cations) then react to form the compound. The nucleation process plays an important role in determining the crystallinity and microstructure of the resultant film. From the discussion of deposition techniques which are physical and chemical deposition methods. Physical deposition techniques contains sputtering deposition, electron beam evaporation and physical vapour deposition (PVD) process have been known for over 100 years and also fabrication films on the substrate, as well as the increasement of the pressure in the chamber due to operation of the sources indicates directly that gases or vapors are desorbed. Chemical deposition process is economically effective and has been industrially exploited to large scale. It can be summarized that thin film characterization techniques include X-ray diffraction (XRD), UV-Vis spectrophotometer, scanning electron microscopy, energy dispersive x-ray diffraction, transmission electron microscopy (TEM). X-rays diffraction (XRD) is a rapid and a powerful technique used to study the phase of a crystalline material, information on unit cell lattice parameters, crystal structure, crystal orientation and crystalline size.

In-situ synthesis of ternary heterojunctions via g-C3N4 coupling with noble-metal-free NiS and CdS with efficient visible-light-induced photocatalytic H2 evolution and mechanism insight

The two-dimensional (2D) graphitic carbon nitride (g-C 3 N 4 ) nanosheets based composites are prepared in the form of the NiS/g-C 3 N 4 , CdS/g-C 3 N 4 and CdS/NiS/g-C 3 N 4 using a facile and reliable method of chemical deposition. The TEM and HRTEM images demonstrated a spectacular representation of the 2D lamellar microstructure of the g-C 3 N 4 with adequately attached CdS and NiS nanoparticles. The changes in crystallinity and the surface elemental valence states of composites with the incorporation of two metal sulphides are studied, which confirmed the formation of composites. The photocatalytic response of the composites was estimated by photodegradation of Rhodamine B (C 28 H 31 ClN 2 O 3 –RhB), and the ternary composite CdS/NiS/g-C 3 N 4 samples exhibited the superior photocatalytic performance. Further, the free radical capture and electron paramagnetic resonance (EPR) spectroscopy experiments identified the main active species that contributed to the photocatalytic reaction. Besides, the samples’ photocatalytic performance was evaluated by photocatalytic hydrogen production. The stability of the performance-optimized composite was determined by employing cyclic experiments over five cycles. The CdS/NiS/g-C 3 N 4 showed the highest efficiency of hydrogen production i.e. about 423.37 μmol.g −1 .h −1 , which is 2.89 times that of the pristine g-C 3 N 4 . Finally, two types of heterojunction structures were proposed to interpret the enhanced photocatalytic efficiency. • The CdS/NiS/g-C 3 N 4 was synthesized by a convenient chemical deposition method. • The CdS and NiS nanoparticles were attached on the surface of g-C 3 N 4 nanosheets. • The loaded metal sulphides could significantly improve the quantum efficiency. • The CdS/NiS/g-C 3 N 4 showed excellent photocatalysis and stability for H 2 evolution. • The ESR spectra indicated that ·O 2 − played a major role during the reaction process.

Evaluation of copper(I)-doped zinc oxide composite nanoparticles on both gram-negative and gram-positive bacteria

Antibiotic resistance is a serious problem all over the world. Inorganic metal oxide nanoparticles are suitable substitutional treatments for organic antibiotic-resistant bacterial infections. Various copper dopped ZnO nanocomposites were prepared with chemical deposition method in aqueous solution. X-ray diffraction (XRD) coupled with energy dispersive spectroscopy results reveals that cuprous oxide is uniformly doped on the surface of ZnO nanoparticles, forming Cu2O/ZnO nanocomposites. In addition, from Transmission electron microscopy (TEM) and scanning electron microscopy analysis, the average size of prepared Cu2O/ZnO composite is about 30 nm. The antibacterial activity of the Cu2O/ZnO composite was examined on two bacteria strains: Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli). When the doping amount of Cu2O reaches more than 5%, a 3.58 log-reduction of S. aureus growth under visible light within 30 mins treatment was observed. The antibacterial activity of Cu2O/ZnO is 2.7-fold higher than pure ZnO and killing bacteria on E. coli with a 1.0 log-reduction in viability. Meanwhile, the bacteriological properties of Cu doped ZnO composites with different valence states (Cu2+, CuO, Cu2O, and Cu0) were compared. Furthermore, the antibacterial mechanism was further discussed in this paper.

Spectroscopic Probing Of Mn-Doped ZnO Nanowires Synthesized via a Microwave-Assisted Route

Dilute magnetic semiconductors such as transition-metal-doped ZnO are potential candidates for spintronic applications. Transition metals such as Mn, Fe, and Cu when doped in ZnO enable spin magnetic properties to conventional semiconductors. Although several techniques such as wet chemical and vapor deposition methods are employed to achieve homogeneous doping in ZnO, these methods have limits pertaining to solubility levels of dopant ion, morphology, competition between intrinsic and extrinsic defects and localization of the defect species. This manuscript is an addition to the vast knowledge of methods and protocols that present the synthesis of transition-metal-doped ZnO. In this report, manganese-doped ZnO is synthesized via a microwave-assisted hydrolysis technique. The defect structure of Mn-doped ZnO wires is investigated via electron paramagnetic resonance and photoluminescence techniques. The analysis indicates that Mn2+ substitutes the Zn ion and dominates the intrinsic defect species in ZnO.

Development of new magnetic adsorbent of walnut shell ash/starch/Fe3O4 for effective copper ions removal: Treatment of groundwater samples

The goal of this investigation was to develop a new magnetic nanocomposite of walnut shell ash (WSA)/starch/Fe3O4 to remove Cu (II) present in groundwater samples. The desired nanocomposites were successfully synthesized by the chemical deposition method. The specific active surface area for pristine WSA and WSA/starch/Fe3O4 magnetic nanocomposites was determined to be 8.1 and 52.6 m2/g, respectively. A central composite design for the response surface method was utilized to study the influence of pH, adsorbent quantity, initial content of Cu (II), temperature, and contact time. This method showed the success of the model to design process variables and to estimate the appropriate response. The P- and F-value determined for the quadratic polynomial model showed the significance and accuracy of the proposed model in examining experimental and predicted data with R2 and Adj.R2 of 0.994 and 0.991, respectively. The Cu adsorption onto WSA and WSA/starch/Fe3O4 obeyed the Freundlich and Langmuir models, respectively. The highest Cu (II) sorption capacity of 29.0 and 45.4 mg/g was attained for WSA and WSA/starch/Fe3O4, respectively. The free energy of Gibbs had a negative value at 25–45 °C indicating that the adsorption process is spontaneous. Also, negative ΔH values for copper adsorption showed that the processes are exothermic. The kinetic adsorption data for WSA and WSA/starch/Fe3O4 followed the pseudo-second order (PSO) model. The ability of the composite adsorbent to remove copper from three groundwater samples showed that it could be reused at least 3 times with appropriate efficiency, depending on the water quality.

CdS nanoparticles with highly exposed (1 1 1) facets decorated on Pt/TiO2 nanotubes for highly efficient photocatalytic H2 evolution

Photocatalytic water splitting is a prospective strategy to solve the shortage of human fossil fuel energy. In this work, we designed and synthesized the Pt as co-catalyst decorated on TiO2 nanotubes/metastable zinc-blende (ZB) CdS nanoparticles (NPs) with highly exposed (111) facets (HPTCA3) via the electrospinning-solvothermal and chemical deposition methods. The H2 evolution rate of HPTCA3 was 15025.38 μmol·g−1·h−1, which was about 111.3 and 2.4 times stronger than that of pure CdS power and Pt-TiO2/CdS hollow nanotubes (HPTC). The XRD patterns showed the presence of acetate promoted the growth of ZB CdS (111) crystal facets, and the photogenerated electrons were easily tended to accumulate on the CdS (111) facets, whichwas conducive to the transmission of electrons on the CdS and TiO2 interface. The type II heterojunction can broaden the visible light response range and accelerate the separation and transfer of photo-generated electrons and holes which can be supported by the Optical and Electrochemical characterizations. Band structure calculations and XPS spectrum indicated that the composite catalyst had an efficient electron transfer mechanism, which was beneficial for the spatial separation of photogenerated carriers. The work provides a rational photocatalyst design to improve the performance of photocatalytic splitting of water into hydrogen.

Effective and selective conversion of nitrate from aqueous solutions to nitrogen gas under neutral pH condition using Al/Cu bimetal-sulfamic acid reduction method

To expand the working pH range of NO3–-N reduction from aqueous solution, a two-step method including the Al/Cu bimetal and sulfamic acid reduction was developed. In this process, Al/Cu bimetallic materials were prepared by chemical deposition method and characterized by EDS, SEM, XRD and XPS. The NO3–-N reduction batch experiment showed that 100% of NO3–-N was reduced and converted to N2 at pH of 7, Al/Cu dosage of 30 g/L and EDTA-2Na concentration of 6 mmol/L. When the pH value was adjusted to 3, 5 and 9, NO3–-N reduction efficiencies ca. 80–97% were also obtained in the first step, and 100% N2 selectivity was further obtained with the second reduction step at pH of 3, 7 and 9. The kinetics study indicated that the Al/Cu reduction process was in accordance with the pseudo-second order kinetics model.

The Effect of Cu<sub>2</sub>O Synthesis Method on its Optical Properties

Cuprous Oxide (Cu2O) is a semiconductor material with excellent photocatalytic properties, a broad range of applications, low fabrication costs, and is non-toxic. We concentrated on the impact of two different synthesis methods in this study. Cu2O synthesis was carried out using two different techniques, which are chemical deposition and hot-soap method. The chemical deposition (CD) method used a copper sulfate pentahydrate precursor in a room temperature reaction. Hot-soap (HS) method employed copper acetylacetonate with reaction at higher temperature. The X-Ray Diffraction analysis reveals a sharp peak with a size of 53.8 nm and a broaden peak with a size of 26.24 nm for particles synthesized by (Cu2O-CD) and (Cu2O-HS), respectively. Using the Tauc Plot method, the band gap of Cu2O-HS is estimated to be 2.65 eV and that of Cu2O-CD to be 1.7 eV. Cu2O-HS emits a noticeable photoluminescence peak at 425 nm, whereas Cu2O-CD emits no peaks in photoluminescence spectra analysis. These findings indicate that Cu2O-HS has a high potential for use in photocatalytic mechanisms.

Physicochemical properties and antibacterial activity of Pt nanoparticles on TiO2 nanotubes as electrocatalyst for methanol oxidation reaction

TiO2 nanotubes were prepared electrochemically as pure Ti sheet in 0.5% HF anodized and annealed under nitrogen acquiring the TiO2 NTs-N2 support. By chemical deposition method using NaBH4 as reducing agent, platinum was deposited on TiO2 NTs-N2 support to gain the Pt NPs/TiO2 NTs-N2 electrocatalyst.Scanning electron microscopy (SEM) and X-ray diffraction (XRD) were applied for the physicochemical characterization of TiO2 NTs-N2 and Pt NPs/TiO2 NTs-N2. The XRD exhibited the an existence of platinum nanoparticles with an average crystallite size of 12 nm, which was regularly combined with TiO2 nanotubes. The Pt NPs/TiO2 NTs-N2 catalyst indicated considerably high electrocatalytic activity and stability for methanol electrocatalytic oxidation reaction in basic medium of KOH. The catalyst Pt NPs/TiO2 NTs-N2 was electrochemically characterized in a basic solution of methanol using cyclic voltammetry (CV) measurement in the absence and an existence of light. The higher poison tolerance and higher methanol oxidation current density observed for the Pt NPs/TiO2 NTs-N2 catalyst suggest that this catalyst supported on TiO2 NTs-N2 has a promising potential applications in the electro catalyst reactions. In addition, the synthesized platinum nanoparticles deposited on TiO2 nanotubes revealed a tremendous antibacterial effects against pathogenic microorganismm.

High-Temperature Annealing of Thin Silicon Suboxide Films Produced by the Method of Gas-Jet Chemical Deposition with Activation by Electron-Beam Plasma

High-Temperature Annealing of Thin Silicon Suboxide Films Produced by the Method of Gas-Jet Chemical Deposition with Activation by Electron-Beam Plasma

Hierarchical ultrathin nanosheet of Ni(OH)2/rGO composite chemically deposited on Ni foam for NOx gas sensors

The nanostructured Ni(OH)2/rGO composite successfully deposited on Ni foam by a chemical deposition method for gas sensor application. Synthesized ultrathin nanosheets of Ni(OH)2 on rGO sheet showed an excellent sensing property to NOx with highest sensitivity 48% at 100ppm NOx concentration and response time for that 7 second.

Optical and Recombination Parameters of CdS1−xTex Thin Films Obtained by the CMBD Method

This paper presents the results of the photoacoustic, SEM, and surface photovoltage experiments performed on the series of CdS1−xTex thin films. These CdS1−xTex (0 ≤ x ≤ 1) thin films were obtained on the glass substrate by the chemical molecular beam deposition (CMBD) method. The polycrystalline character of these films was revealed by SEM pictures. From the experimental optical characteristics, the optical absorption coefficient spectra of the samples and values of their energy gaps vs. their composition were determined. From the surface photovoltage characteristics, the diffusion lengths of the carriers were also determined.

Laser-Induced Chemical Liquid-Phase Deposition Plasmonic Gold Nanoparticles on Porous TiO2 Film with Great Photoelectrochemical Performance

This paper considers the photoelectrochemical characteristics of a composite porous TiO2 thin film with deposited plasmonic gold nanoparticles. The deposition of gold nanoparticles was carried out by the laser-induced chemical liquid-phase deposition (LCLD) method. The structural characteristics of the composite have been studied; it has been shown that the porous TiO2 film has a lattice related to the tetragonal system and is in the anatase phase. Gold nanoparticles form on the surface of a porous TiO2 film. A complex of photoelectrochemical measurements was carried out. It was shown that the deposition of plasmonic gold nanoparticles led to a significant increase in the photocurrent density by ~820%. The proposed concept is aimed at testing the method of forming a uniform layer of plasmonic gold nanoparticles on a porous TiO2 film, studying their photocatalytic properties for further scaling, and obtaining large area Au/TiO2/FTO photoelectrodes, including in the roll-to-roll process.

Clean surface additive manufacturing of aramid paper-based electrically heated devices for medical therapy application

Flexible thin-film heaters with high heat generation performance and good thermal stability have great potential for medical wearable thermal management applications. However, the current preparation of flexible electrothermal devices mainly uses complex chemical deposition methods, which are interspersed with many environmentally unfriendly chemical wastewaters left by the preparation. In this study, we used water-free plasma treatment and magnetron sputtering techniques to prepare conductive silver/aramid fiber paper (Ag/AFP) flexible thin film heaters. The resultant Ag/AFP sputtered with 6 min exhibited fast thermal response and efficient Joule heating characteristics, reaching 120 °C in less than 6 s at an applied voltage of 1.2 V. Ag/AFP also provided excellent mechanical properties that could withstand bending, folding, and wrinkling without significant loss of electrical and thermal properties. When used in a thermotherapy patch, the Ag/AFP has unique synergistic antibacterial and thermal therapy. The results showed that magnetron sputtering combined with plasma treatment would provide a clean pathway for fabricating wearable textiles/devices.

Synthesis of Carbon Nanotubes Using Plant Source and Study their Properties

In this study the normal and activated charcoal were used to prepare normal and activated multi walled carbon nanotubes (MWCNTs) from same plant (Citrus aurantium) which is a source of carbon by Chemical Flame Deposition method (CFDM). The obtained products were analyzed using FESEM, FTIR, XRD, and Raman spectroscopy. The FESEM image of normal charcoal revealed that it has much less nanopores than activated charcoal. The ratios of ID/IG for the normal and activated MWCNTs were 0.85 and 0.91 respectively, which shows that use activated charcoal as a source enhance the disorder and the defects on the carbon nanotubes. The results demonstrate and confirmed that a carbon nanotubes which were prepared from normal and activated charcoal have some disfigurements and have converging diameter nearly (31-88 nm) and (37-70nm) for normal and activated MWCNTs with length about (1-2) μm respectively.

Preparation of core-shell Ag3PO4@GOQDs and degradation of ciprofloxacin under visible light

To solve the problem of photocorrosion of Ag3PO4, a chemical deposition method was used to prepare a visible-light-active core-shell composite (Ag3PO4@GOQDs) photocatalyst containing silver phosphate (Ag3PO4), graphene oxide (GO), and graphene oxide quantum dots (GOQDs). The degradation efficiency of 2.5 wt% Ag3PO4@GOQDs for ciprofloxacin was 98.7% within 18 min through the synergistic effect of adsorption and photocatalysis. Even after 6 repeated cycles, Ag3PO4@GOQDs exhibited excellent stability. GOQDs improved the adsorption performance and promoted the transmission of photogenerated electrons, whereas the coating of Ag3PO4 slowed down the photocorrosion and enhanced the stability and photocatalytic activity of the interface. Free radical capture experiments confirmed that h+ and •O2– were the main active species during the photocatalytic degradation of ciprofloxacin.

The Effect of Ag Content on the Structural, Optical, and Cytotoxicity Properties of TiO2 Nanopowders Grown from TiO(OH)2 Precursor by the Chemical Deposition Method

The Effect of Ag Content on the Structural, Optical, and Cytotoxicity Properties of TiO2 Nanopowders Grown from TiO(OH)2 Precursor by the Chemical Deposition Method

Nanostructured ZnS obtained by a simple and low-cost chemical deposition method for clean energy thin films devices

Nanostructured ZnS obtained by a simple and low-cost chemical deposition method for clean energy thin films devices