scholarly journals Selective Adsorption of Potassium in Seawater by CoHCF Thin Film Electrode and Its Electrochemical Desorption/Regeneration

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3592
Author(s):  
Nan Zhang ◽  
Tohru Kawamoto ◽  
Hiroshi Watanabe ◽  
Yong Jiang ◽  
Zhenya Zhang ◽  
...  

Cobalt Hexacyanoferrate (CoHCF) was tested for the selective uptake of K from seawater and the electrochemical method was adopted for the desorption and regeneration of the material. Powder form CoHCF could adsorb about 6.5 mmol/g of K from the seawater. For the ease of the electrochemical desorption and regeneration, CoHCF thin film was coated onto the Indium Tin Oxide (ITO) glass to obtain a CoHCF electrode. K adsorption kinetics on CoHCF thin film was found to be well fitted with the intraparticle diffusion model, which was a two-step process. Five consecutive adsorption-desorption-regeneration cycles were carried out to know the gradual decrease in the adsorption capacity owing to changes in the redox states of two metals, Co and Fe, in the material. Fourier Transform Infrared Spectroscopy (FT-IR) and Ultraviolet-Visible (UV-Vis) measurement results corresponded to the color change of CoHCF thin film, indicating the valence change of transition metals and the exchange of alkali metal cations happened on the CoHCF at different operation stages. In order to elucidate the reaction mechanism, composition of the material was analysis in the following steps: adsorption, desorption, and regeneration. It was proved that the system based on CoHCF thin film modified electrode had the potential of recovering potassium from seawater.

2018 ◽  
Vol 382 ◽  
pp. 364-368
Author(s):  
Uwaisulqarni M. Osman ◽  
Azieda Syafika N. Farizal ◽  
Nurhayati Ishak ◽  
Mohd Hasmizam Razali ◽  
M.I.N. Isa

Organic compound containing thiosemicarbazide moiety has been successfully synthesized. The new synthesized dyes, N-(3-(Trifluoromethylbenzaldehyde)benzylidine thiosemi- carbazide (3-TFT) was characterized by spectroscopic technique namely, CHNS elemental analysis, Fourier Transform Infra-Red analysis (FT-IR), UV-Visible analysis (UV-Vis),1H and13C Nuclear Magnetic Resonance (NMR). The thin films of this dye have been prepared using a spin coating technique and deposited on indium tin oxide (ITO) glass substrate. The main highlight was an electrical conductivity of thin films which was measured using four point probing system in a range of light intensity, 25 Wm-2until 200Wm-2. The potential electrical conductivity of 3-TFT dye was found gradually increased until reached the maximum conductivity values of 0.1489 Scm-1at light intensity of 100 Wm-2in the most diluted concentration at 1x10-5M.


2013 ◽  
Vol 1530 ◽  
Author(s):  
Neha Batra ◽  
Monika Tomar ◽  
Vinay Gupta

ABSTRACTZinc oxide (ZnO) thin film deposited onto indium tin oxide (ITO) coated Corning glass substrates using pulsed laser deposition (PLD) technique has been used as a matrix for realization of an efficient urea biosensor after immobilization of urease (Urs) enzyme onto the surface of ZnO. The bioelectrode (Urs/ZnO/ITO/glass) is found to be exhibiting an enhanced sensitivity of 22μΑmΜ−1cm−2 towards urea over a wide detection range of 5-200 mg/dl. The relatively low value of Michaelis menten constant (Km= 0.94mM) indicates high affinity of the immobilized urease towards the analyte (urea). The prepared biosensor retains 90% of its activity for more than 10 weeks. The observed enhanced response characteristics of bioelectrode are attributed to the growth of the matrix (highly c-axis oriented ZnO thin film) with desired surface morphology and high electron communication feature. The results confirm the promising application of PLD grown ZnO thin film as an efficient matrix for urea detection.


2012 ◽  
Vol 485 ◽  
pp. 23-26 ◽  
Author(s):  
Xiu Cheng Zheng ◽  
Guang Ping Zheng ◽  
Zheng Lin ◽  
Zhi Yuan Jiang

Ferroelectric0.90Bi0.5Na0.5TiO3-0.10BaTiO3(0.90BNT-0.10BT) thin film with single perovskite phase is prepared using an improved sol-gel spin coating method onto indium-tin-oxide (ITO) glass substrates. A new solution process is developed for the preparation of precursor solution which is stable in air, presenting a low gelation and trend to the formation of precipitates. The as-prepared thin film is crystallized into single perovskite phase and has good ferroelectric properties. It is remarkable that the thin films show excellent heat-to-electrical energy conversion properties. The results of this work for the first time demonstrate the feasibility of using lead-free BNT-BT films for pyroelectric energy harvesting.


2016 ◽  
Vol 78 (5-8) ◽  
Author(s):  
Khairul Aimi Yusof ◽  
Rohanieza Abdul Rahman ◽  
Muhammad AlHadi Zulkefle ◽  
Sukreen Hana Herman ◽  
Wan Fazlida Hanim Abdullah

Titanium dioxide (TiO2) thin films were fabricated on indium tin oxide (ITO) glass substrates using the spin coating technique and further were implemented as sensing membranes of the extended gate field effect transistor (EGFET) based pH sensor. The as-deposited thin films were annealed at different temperatures from 200 - 600 °C in room ambient for 20 min. The effects of different annealing temperatures on electrical and crystalline properties were analyzed by I-V two point probes measurement and X-ray diffraction respectively. Meanwhile, the surface morphology of thin films was observed by field emission scanning electron microscope (FESEM). We then measured the transfer characteristics (ID-VG) of the TiO2/ITO sensing membrane using a semiconductor parametric device analyzer for sensor characterization. It was found that, TiO2/ITO sensing membrane annealed at 300 °C achieved higher sensitivity and good linearity of 51.48 mV/pH and 0.99415, respectively in the pH buffer solutions of 4, 7, 10, and 12. Thin film annealed at 300 °C gives higher conductivity thin film of 384.62 S/m. We found that the conductivity of TiO2/ITO thin films was proportional with the sensitivity of sensing membrane.  


2005 ◽  
Vol 475-479 ◽  
pp. 3689-3692
Author(s):  
Hui Zhong Ma ◽  
Lan Zhang ◽  
Jun Jie Zhang ◽  
Yun Hai Du ◽  
Ning Yao ◽  
...  

A flexible carbon thin film was prepared by laser induced when phase changing of polyimide thin film. There is no substrate for this thin film. It could be curved at any angle. The electron emission properties of the prepared thin film were measured by a diode mechanism; the thin film was used as a cathode and indium-tin-oxide (ITO) glass as an anode. The turn-on field of the thin film was about 2.1 V/µm. The current density of the thin film was about 150 µA/cm2 at the electric field of 4.5 V/µm. The electron emission measurements indicate that the thin film could be a good candidate electron emission material in flat panel display or be used as other electron source. The morphology and structure of the thin film were investigated by optical microscope and Raman spectroscopy.


2012 ◽  
Vol 486 ◽  
pp. 417-421 ◽  
Author(s):  
Xiao Yan Zhang ◽  
Xi Wei Qi ◽  
Jian Quan Qi ◽  
Xuan Wang

Multiferroic La-doped Bi1-xLaxFeO3 thin films were prepared on conductive indium tin oxide (ITO)/glass substrates through a simple sol-gel process. The crystal structure of La-doped Bi1-xLaxFeO3 thin films annealed at different temperature was determined to be rhombohedral of R3m space and free of secondary phases. The grain size of La-doped BiFeO3 thin films tends to become larger and the grain boundary is gradually ambiguous compared to pure BiFeO3. The double remanent polarization 2Pr of Bi0.9La0.1FeO3 thin film annealed at 500°C is 6.66 µC/cm2, which is slightly improved than that of pure BiFeO3 thin film. With the increase of La-doping levels, the dielectric constant is increased and the dielectric loss is obviously decreased.


2013 ◽  
Vol 537 ◽  
pp. 109-113
Author(s):  
Xi Wei Qi ◽  
Xiao Yan Zhang ◽  
Xuan Wang ◽  
Hai Bin Sun ◽  
Jian Quan Qi

A series of Dy doped La and Sc solution of BiFeO3 thin films have been prepared by using spin-coating process on conductive indium tin oxide (ITO)/glass substrates, which a simple sol-gel possess is applied and annealed at 500°C. With the increase of content of Dy, the strongest peak (110) of La and Sc solution BiFeO3 film tends to further broaden. There is no second phase existence within the present Dy doping level. Cross section scanning electron microscope (SEM) pictures revealed that the thickness of BiFeO3 film was about 370 nm. For Dy doping level is 0.05, the maximum double remanent polarization 2Pr of as-prepared BiFeO3 thin film is15.44 μC/cm2. Image of atomic force microscopy indicated that the root-mean-square surface roughness value of as-prepared BiFeO3 thin film is 2.11 nm. The dielectric constant of as-prepared films tends to firstly increase and then decrease with the increase of Dy content


2011 ◽  
Vol 492 ◽  
pp. 202-205 ◽  
Author(s):  
Xi Wei Qi ◽  
Xiao Yan Zhang ◽  
Xuan Wang ◽  
Hai Bin Sun ◽  
Jian Quan Qi

BiFeO3 thin films were spin-coated on conductive indium tin oxide (ITO)/glass substrates by a simple sol-gel possess annealed at 470-590°C. The crystal structure of as-prepared BiFeO3 thin films annealed at different temperature was determined to be rhombohedral of R3m space and free of secondary phases was also confirmed. Cross section scanning electron microscope (SEM) pictures revealed that the thickness of BiFeO3 thin film was about 320 nm. The double remanent polarization 2Pr of BiFeO3 thin film annealed at 500°C is 2.5 μC/cm2 without applied field at room temperature. Image of atomic force microscopy indicated that the root-mean-square surface roughness value of BiFeO3 thin film was 6.13 nm.


2016 ◽  
Vol 16 (4) ◽  
pp. 3674-3678 ◽  
Author(s):  
Xu Mao ◽  
Jia-Ning Zhang ◽  
Li-Hua Gao ◽  
Yu Su ◽  
Peng-Xia Chen ◽  
...  

An electrostatically self-assembled multilayer thin film consisting of alternating layers of Keggin polyoxometalate of Zn-substituted tungstoborate (BW11Zn) and Rhodamine B (RhB) has successfully been prepared on a quartz and indium-tin oxide (ITO) glass substrate. The ultraviolet-visible (UV-vis) absorption spectra demonstrated that the electrostatically self-assembled film of (BW11Zn/RhB)n was uniformly deposited layer by layer, and the RhB molecules in the film formed the J-aggregation. The photoelectrochemical investigations showed that the films generated stable cathodic photocurrents that originated from RhB, and the maximal cathodic photocurrent density generated by an eight-layer film was 4.9 μA/cm2 while the film was irradiated with 100 mW/cm2 polychromatic light of 730 nm > λ > 325 nm at an applied potential of 0 V versus a saturated calomel electrode.


2016 ◽  
Vol 78 (3) ◽  
Author(s):  
A. R. N. Laily ◽  
S. Hasiah ◽  
N. A. Nik Aziz ◽  
A. N. Dagang ◽  
M. S. M. Ghazali

In this work, Indium Tin oxide (ITO) glass used was 27˚C to 200˚C as substrate. The polymer used was Poly (3-Dodecylthiophene) (P3DT) thin film, Ixora coccinea L dan Rhodomyrtus tomentosa (Aiton) Hassk. as natural dye. The P3DT films were prepared using electrochemistry method at room temperature. Then, the natural dye was prepared layer by layer via spin coating method. Influence of heat treatment on the electrical properties and the efficiency of the system were investigated by Four Point Probes (FPP) under different light radiation (range of 0 Wm-2 to 200Wm-2), Hall Effect and thicknesss measurement. The electrical conductivity of the solar cell system increased with the increment of light radiations and the temperature of substrates. From Hall Effect measurement, the type of sample, Hall mobility, and highest charge carrier in the sample obtained. The thin film thickness was determined. The results show that the sample is suitable for further solar cell fabrications.


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