Materials Science in Semiconductor Processing, 2015
ABSTRACT In this study, the titanium/titanium dioxide nanotube array (Ti/TiO2-NTA) electrode was ... more ABSTRACT In this study, the titanium/titanium dioxide nanotube array (Ti/TiO2-NTA) electrode was prepared with anodic oxidation of Ti foil electrode. The morphology of Ti/TiO2-NTA electrode was evaluated with scanning electron microscopy images. The results showed that the inner diameter of nanotubes is below of 100 nm. The electrochemical behavior of the as-prepared Ti/TiO2-NTA electrode was studied using the cyclic voltammetry. In addition, a significant photoelectrochemical behavior of the p-hydroxybenzoic acid (p-HBA) was observed on the Ti/TiO2 electrode using the hydrodynamic photoamperometry experiments. Then, the photoelectrocatalytic (PEC) degradation of the p-HBA was performed by this electrode, and compared with photocatalytic (PC), electrooxidation (EC), and direct photolysis by ultra-violet ray. It was found from mechanistic studies that the rate constant for the PEC process of Ti/TiO2-NTA electrode was higher than other degradation processes. The p-HBA concentration monitoring was carried out with the differential pulse voltammetry. Finally, the effects of the solution pH, applied potential, and the p-HBA concentration on the degradation efficiencies were studied and the results showed that the optimum pH for the photoelectrocatalytic degradation was equal to 7.00. The optimum potential and the optimum concentration were about 0.5 V (vs. Ag|AgCl|KCl (3M) as reference electrode) and 0.129 mM in the studied ranges, respectively.
ABSTRACT The widely utilization of phenol and its derivatives such as 3-nitrophenol (3-NP) has le... more ABSTRACT The widely utilization of phenol and its derivatives such as 3-nitrophenol (3-NP) has led to the worldwide pollution in the environment. In this study, Ti/TiO2 photoelectrode was prepared with anodic oxidation of Ti foil electrode and then the photoelectrocatalytic (PEC) degradation of 3-NP was performed via this electrode, comparing with photocatalytic (PC), electrooxidation and direct photolysis by ultraviolet light. A significant photoelectrochemical synergetic effect in 3-NP degradation was observed on the Ti/TiO2 electrode and rate constant for the PEC process of Ti/TiO2 electrode was about three times as high as its PC degradation process. 3-NP concentration monitoring was carried out with differential pulse voltammetry. Results showed that PEC degradation has highest effect on concentration decreasing of 3-NP at solution and degraded it about 38 %, while other processes degradation efficiencies were about 4, 7, and 12 % for electrooxidation, direct photolysis and photocatalytic degradation, respectively. Finally, effects of solution pH and applied potential on degradation efficiency were studied and results showed that optimum pH for degradation is equal 4.00 and optimum potential is 1.2 V vs. Ag|AgCl|KCl (3M) reference electrode.
Bioelectrocatalysis is a phenomenon concerned with biological catalysts, which accelerate the ele... more Bioelectrocatalysis is a phenomenon concerned with biological catalysts, which accelerate the electrochemical reactions. Bioelectrocatalysis has been widely explored by the research community in various directions. Enzymes can catalyze different chemical reactions in living organisms by enzymes as the most important biological catalysts. These enzymatic biocatalysts are commercially available and commonly called enzyme electrodes. Electron transfer between the active center of the enzyme and the electrode can be performed either by direct electron transfer (DET) or by means of mediators (i.e. mediated electron transfer (MET)), which are discussed in details in the presented review. Therefore, different strategies have been used to increase the efficiency and stability of bioelectrocatalysis. In this review, different strategies of the bioelectrode designs have been discussed and the application of the common bioelectrodes used in the biosensors have been presented in the various fie...
An electrochemical immunoassay is prepared for the determination of PSA using a composite of AgAu... more An electrochemical immunoassay is prepared for the determination of PSA using a composite of AgAuPt, synthesized by galvanic replacement between the Ag framework and Pt and Au ions. The AgPt labeled-antibody is applied as the detection layer.
Materials Science in Semiconductor Processing, 2015
ABSTRACT In this study, the titanium/titanium dioxide nanotube array (Ti/TiO2-NTA) electrode was ... more ABSTRACT In this study, the titanium/titanium dioxide nanotube array (Ti/TiO2-NTA) electrode was prepared with anodic oxidation of Ti foil electrode. The morphology of Ti/TiO2-NTA electrode was evaluated with scanning electron microscopy images. The results showed that the inner diameter of nanotubes is below of 100 nm. The electrochemical behavior of the as-prepared Ti/TiO2-NTA electrode was studied using the cyclic voltammetry. In addition, a significant photoelectrochemical behavior of the p-hydroxybenzoic acid (p-HBA) was observed on the Ti/TiO2 electrode using the hydrodynamic photoamperometry experiments. Then, the photoelectrocatalytic (PEC) degradation of the p-HBA was performed by this electrode, and compared with photocatalytic (PC), electrooxidation (EC), and direct photolysis by ultra-violet ray. It was found from mechanistic studies that the rate constant for the PEC process of Ti/TiO2-NTA electrode was higher than other degradation processes. The p-HBA concentration monitoring was carried out with the differential pulse voltammetry. Finally, the effects of the solution pH, applied potential, and the p-HBA concentration on the degradation efficiencies were studied and the results showed that the optimum pH for the photoelectrocatalytic degradation was equal to 7.00. The optimum potential and the optimum concentration were about 0.5 V (vs. Ag|AgCl|KCl (3M) as reference electrode) and 0.129 mM in the studied ranges, respectively.
ABSTRACT The widely utilization of phenol and its derivatives such as 3-nitrophenol (3-NP) has le... more ABSTRACT The widely utilization of phenol and its derivatives such as 3-nitrophenol (3-NP) has led to the worldwide pollution in the environment. In this study, Ti/TiO2 photoelectrode was prepared with anodic oxidation of Ti foil electrode and then the photoelectrocatalytic (PEC) degradation of 3-NP was performed via this electrode, comparing with photocatalytic (PC), electrooxidation and direct photolysis by ultraviolet light. A significant photoelectrochemical synergetic effect in 3-NP degradation was observed on the Ti/TiO2 electrode and rate constant for the PEC process of Ti/TiO2 electrode was about three times as high as its PC degradation process. 3-NP concentration monitoring was carried out with differential pulse voltammetry. Results showed that PEC degradation has highest effect on concentration decreasing of 3-NP at solution and degraded it about 38 %, while other processes degradation efficiencies were about 4, 7, and 12 % for electrooxidation, direct photolysis and photocatalytic degradation, respectively. Finally, effects of solution pH and applied potential on degradation efficiency were studied and results showed that optimum pH for degradation is equal 4.00 and optimum potential is 1.2 V vs. Ag|AgCl|KCl (3M) reference electrode.
Bioelectrocatalysis is a phenomenon concerned with biological catalysts, which accelerate the ele... more Bioelectrocatalysis is a phenomenon concerned with biological catalysts, which accelerate the electrochemical reactions. Bioelectrocatalysis has been widely explored by the research community in various directions. Enzymes can catalyze different chemical reactions in living organisms by enzymes as the most important biological catalysts. These enzymatic biocatalysts are commercially available and commonly called enzyme electrodes. Electron transfer between the active center of the enzyme and the electrode can be performed either by direct electron transfer (DET) or by means of mediators (i.e. mediated electron transfer (MET)), which are discussed in details in the presented review. Therefore, different strategies have been used to increase the efficiency and stability of bioelectrocatalysis. In this review, different strategies of the bioelectrode designs have been discussed and the application of the common bioelectrodes used in the biosensors have been presented in the various fie...
An electrochemical immunoassay is prepared for the determination of PSA using a composite of AgAu... more An electrochemical immunoassay is prepared for the determination of PSA using a composite of AgAuPt, synthesized by galvanic replacement between the Ag framework and Pt and Au ions. The AgPt labeled-antibody is applied as the detection layer.
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