Investigation on the application of titania nanorod arrays to the determination of chemical oxygen demand

In the present paper, the TiO2 nanorod arrays electrode was developed as a sensor for the determination of chemical oxygen demand (COD) based on a photoelectrochemical degradation principle. Effects of common parameters, such as applied potential, light intensity and pH on its analytical performance were investigated. Under the optimized conditions, the nanorod arrays electrode was successfully applied in the COD determination for both synthetic and real samples. In the COD determination, the proposed method can achieve a practical detection limit of 18.3 mg L−1 and a linear range of 20–280 mg L−1. Furthermore, the results obtained by the proposed method were well correlated with those obtained using the conventional (i.e., dichromate) COD determination method. The main advantages of this COD determination method were its simplicity, long term stability and environmental friendly (corrosive and toxic reagents not consumed). This work would open a new application area (COD determination) of the TiO2 nanorod arrays.

The figure shows the correlation between the experimental COD values by the titania nanorod array sensors and standard COD values (dichromate method). The correlation was satisfactory with correlation coefficient (R) 0.9801, demonstrating the results obtained by our method were in good agreement with the standard method.Figure optionsDownload as PowerPoint slideHighlights
► TiO2 nanorod arrays were used for the determination of COD value for the first time.
► Obtained values correlated with conventional (i.e., dichromate) COD determination method.
► Described sensor shows long term stability and environmental friendly.