Modification Of TiO₂ Nanotubes And Photoelectrochemical Detection Of H₂O₂

Hydrogen peroxide?H₂O₂?is an industrial raw material that is widely used in light industry,medicine and food industries.Studies have shown that hydrogen peroxide can damage human cells after entering the body,and high concentrations of H₂O₂ can even induce diseases such as neurodegeneration,diabetes,and dementia.In recent years,China has attached great importance to the research and development of new products of hydrogen peroxide,and its consumption in various industries has been increasing.Therefore,the detection of hydrogen peroxide has important significance.The detection of H₂O₂ by the photoelectrochemical sensor method has the advantages of rapid response,low detection limit,high sensitivity,and simple method,so it has been widely used.Titanium dioxide nanotubes,due to their unique photocatalytic properties,have made outstanding contributions in the field of sensors.Anodic oxidation was used to prepare Ti O₂nanotubes,and cyclic voltammetry was used to prepare RGO/Ag_?X?-TNTs photoelectrodes.The photoelectrode is optimized by controlling the applied voltage and the number of cycles of cyclic voltammetry.At the same time,the photoelectrode is used to detect H₂O₂ by the current-time method.The results show that the RGO/Ag_?11?-TNTs photoelectrode,under the irradiation of ultraviolet light,when the applied voltage is 0.3 V,the highest photocurrent will be shown when the H₂O₂ is detected.?I?I(?A cm^-2)=3.02logc?n M?+36.71(R²=0.9800,10^-7?10^-2 n M),?II?I(?A cm^-2)=3.23logc?n M?+33.74(R²=0.9819,10^-1?10⁴ n M),?III?I(?A cm^-2)=8.46logc?n M?+8.41?R²=0.9708,10⁵?10⁷ n M?.The sensitivity of the third curve is 10.08?A m M^-1 cm^-2 and the detection limit is 20?M?S/N=3?.The continuous ion layer adsorption reaction method?STLAR?was used to form Bi OCl_?X?-TNTs?x=20,25,30,35,40?composite materials.It is observed by SEM that Bi OCl is made of countless nano flakes.To optimize the voltage applied to this photoelectrode,under ultraviolet light irradiation,by current-time method,when the applied voltage was 0.2V,0.1 m M H₂O₂+0.01 M PBS solution was detected and it was found that Bi OCl_?30?-TNTs showed the highest light to H₂O₂ Current.The linear equations for photocurrent and concentration when detecting H₂O₂(10^-1 n M?10⁷ n M)are:I(?A cm^-2)=2.01og C?n M?+36.28(R²=0.9833,10^-7?10^-2 n M),I(?A cm^-2)=6.00log C?n M?+40.11(R²=0.9407,10^-1n M?10²n M),I(?A cm^-2)=2.23log C?n M?+47.05?R²=0.9943,10³ n M?10⁷ n M?.The detection limit of the second curve is 0.05 n M?S/N=3?,the sensitivity is 14.69?A m M^-1 cm^-2,and the sensor has excellent selectivity and good stability.