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Fabrication of potato-like silver molybdate microstructures for photocatalytic degradation of chronic toxicity ciprofloxacin and highly selective electrochemical detection of H 2 O 2

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ABSTRACT

In the present work, potato-like silver molybdate (Ag2MoO4) microstructures were synthesized through a simple hydrothermal method. The microstructures of Ag2MoO4 were characterized by various analytical and spectroscopic techniques such as XRD, FTIR, Raman, SEM, EDX and XPS. Interestingly, the as-prepared Ag2MoO4 showed excellent photocatalytic and electrocatalytic activity for the degradation of ciprofloxacin (CIP) and electrochemical detection of hydrogen peroxide (H2O2), respectively. The ultraviolet-visible (UV-Vis) spectroscopy results revealed that the potato-like Ag2MoO4 microstructures could offer a high photocatalytic activity towards the degradation of CIP under UV-light illumination, leads to rapid degradation within 40 min with a degradation rate of above 98%. In addition, the cyclic voltammetry (CV) and amperometry studies were realized that the electrochemical performance of Ag2MoO4 modified electrode toward H2O2 detection. Our H2O2 sensor shows a wide linear range and lower detection limit of 0.04–240 μM and 0.03 μM, respectively. The Ag2MoO4 modified electrode exhibits a high selectivity towards the detection of H2O2 in the presence of different biological interferences. These results suggested that the development of potato-like Ag2MoO4 microstructure could be an efficient photocatalyst as well as electrocatalyst in the potential application of environmental, biomedical and pharmaceutical samples.

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(A) Cyclic voltammograms for the reduction of H2O2 on bare GCE (a,c) and Ag2MoO4 modified GCE (b,d) in absence (a,b) and presence (c,d) of 200 μM H2O2 containing N2 saturated 0.05 M PBS (pH 7) at a scan rate of 50 mV/s. (B) Cyclic voltammograms of Ag2MoO4 modified GCE in N2 saturated 0.05 M PBS (pH 7) in the absence and presence of H2O2 with different concentrations (a–k: 0 to 1 mM) at a scan rate of 50 mV/s.
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f8: (A) Cyclic voltammograms for the reduction of H2O2 on bare GCE (a,c) and Ag2MoO4 modified GCE (b,d) in absence (a,b) and presence (c,d) of 200 μM H2O2 containing N2 saturated 0.05 M PBS (pH 7) at a scan rate of 50 mV/s. (B) Cyclic voltammograms of Ag2MoO4 modified GCE in N2 saturated 0.05 M PBS (pH 7) in the absence and presence of H2O2 with different concentrations (a–k: 0 to 1 mM) at a scan rate of 50 mV/s.

Mentions: Cyclic voltammetry studies of the H2O2 sensor was demonstrated using bare GCE (a,c) and (b,d) Ag2MoO4 modified GCE in absence (curve a & b) and presence of 200 μM H2O2 (curve c & d) containing N2 saturated 0.05 M PBS (pH 7) at a scan rate 50 mV/s. In the absence of H2O2 (curve a & b), the results clearly indicates that there is no significant reduction peak appeared in the selected potential window. Whereas, in the presence of 200 μM H2O2 on Ag2MoO4 modified GCE (curve d) shows a strong and higher reduction peak current appeared at the lower onset potential −0.26 V due to the catalytic behavior of Ag2MoO4. Although, we also observed a slight and not considerable reduction peak in the bare GCE at the longer potential −0.7 V (curve c). The reduction peak current of H2O2 on Ag2MoO4 modified GCE is 10 times much higher than that of bare GCE. The above results confirmed that Ag2MoO4 modified GCE has high catalytic ability for H2O2 detection. Consequently, Ag2MoO4 are suitable as mediators to transfer electron between H2O2 and working electrode and make possible electrochemical regeneration following electron exchange with H2O2. The possible mechanisms for the electrochemical reduction of hydrogen peroxide as shown in Eqs (7, 8, 9). In order to investigate the electrocatalytic activity of Ag2MoO4 modified GCE, CVs were performed in the presence of different addition of H2O2 in 0.05 M PBS (pH 7), as shown in Fig. 8B. The reduction peak current of H2O2 was linearly increased with increasing the H2O2 concentration from 0 to 1 mM, which revealing electrocatalytic activity of Ag2MoO4 modified GCE toward the H2O2. Furthermore, the low level detection, sensitivity and linear range of H2O2 were clearly discussed in amperometric (i-t) section.


Fabrication of potato-like silver molybdate microstructures for photocatalytic degradation of chronic toxicity ciprofloxacin and highly selective electrochemical detection of H 2 O 2
(A) Cyclic voltammograms for the reduction of H2O2 on bare GCE (a,c) and Ag2MoO4 modified GCE (b,d) in absence (a,b) and presence (c,d) of 200 μM H2O2 containing N2 saturated 0.05 M PBS (pH 7) at a scan rate of 50 mV/s. (B) Cyclic voltammograms of Ag2MoO4 modified GCE in N2 saturated 0.05 M PBS (pH 7) in the absence and presence of H2O2 with different concentrations (a–k: 0 to 1 mM) at a scan rate of 50 mV/s.
© Copyright Policy - open-access
Related In: Results  -  Collection

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Show All Figures
getmorefigures.php?uid=PMC5037444&req=5

f8: (A) Cyclic voltammograms for the reduction of H2O2 on bare GCE (a,c) and Ag2MoO4 modified GCE (b,d) in absence (a,b) and presence (c,d) of 200 μM H2O2 containing N2 saturated 0.05 M PBS (pH 7) at a scan rate of 50 mV/s. (B) Cyclic voltammograms of Ag2MoO4 modified GCE in N2 saturated 0.05 M PBS (pH 7) in the absence and presence of H2O2 with different concentrations (a–k: 0 to 1 mM) at a scan rate of 50 mV/s.
Mentions: Cyclic voltammetry studies of the H2O2 sensor was demonstrated using bare GCE (a,c) and (b,d) Ag2MoO4 modified GCE in absence (curve a & b) and presence of 200 μM H2O2 (curve c & d) containing N2 saturated 0.05 M PBS (pH 7) at a scan rate 50 mV/s. In the absence of H2O2 (curve a & b), the results clearly indicates that there is no significant reduction peak appeared in the selected potential window. Whereas, in the presence of 200 μM H2O2 on Ag2MoO4 modified GCE (curve d) shows a strong and higher reduction peak current appeared at the lower onset potential −0.26 V due to the catalytic behavior of Ag2MoO4. Although, we also observed a slight and not considerable reduction peak in the bare GCE at the longer potential −0.7 V (curve c). The reduction peak current of H2O2 on Ag2MoO4 modified GCE is 10 times much higher than that of bare GCE. The above results confirmed that Ag2MoO4 modified GCE has high catalytic ability for H2O2 detection. Consequently, Ag2MoO4 are suitable as mediators to transfer electron between H2O2 and working electrode and make possible electrochemical regeneration following electron exchange with H2O2. The possible mechanisms for the electrochemical reduction of hydrogen peroxide as shown in Eqs (7, 8, 9). In order to investigate the electrocatalytic activity of Ag2MoO4 modified GCE, CVs were performed in the presence of different addition of H2O2 in 0.05 M PBS (pH 7), as shown in Fig. 8B. The reduction peak current of H2O2 was linearly increased with increasing the H2O2 concentration from 0 to 1 mM, which revealing electrocatalytic activity of Ag2MoO4 modified GCE toward the H2O2. Furthermore, the low level detection, sensitivity and linear range of H2O2 were clearly discussed in amperometric (i-t) section.

View Article: PubMed Central - PubMed

ABSTRACT

In the present work, potato-like silver molybdate (Ag2MoO4) microstructures were synthesized through a simple hydrothermal method. The microstructures of Ag2MoO4 were characterized by various analytical and spectroscopic techniques such as XRD, FTIR, Raman, SEM, EDX and XPS. Interestingly, the as-prepared Ag2MoO4 showed excellent photocatalytic and electrocatalytic activity for the degradation of ciprofloxacin (CIP) and electrochemical detection of hydrogen peroxide (H2O2), respectively. The ultraviolet-visible (UV-Vis) spectroscopy results revealed that the potato-like Ag2MoO4 microstructures could offer a high photocatalytic activity towards the degradation of CIP under UV-light illumination, leads to rapid degradation within 40 min with a degradation rate of above 98%. In addition, the cyclic voltammetry (CV) and amperometry studies were realized that the electrochemical performance of Ag2MoO4 modified electrode toward H2O2 detection. Our H2O2 sensor shows a wide linear range and lower detection limit of 0.04–240 μM and 0.03 μM, respectively. The Ag2MoO4 modified electrode exhibits a high selectivity towards the detection of H2O2 in the presence of different biological interferences. These results suggested that the development of potato-like Ag2MoO4 microstructure could be an efficient photocatalyst as well as electrocatalyst in the potential application of environmental, biomedical and pharmaceutical samples.

No MeSH data available.


Related in: MedlinePlus