Preparation of Bi₂O₃@TiO₂ Nanotube Arrays Composite Electrodes and the Detection Performance for 4‐Nitrophenol

TiO 2 nanotube arrays (TNTA) were prepared by anodization, and then bismuth oxide (Bi 2 O 3 ) was deposited on TNTA by vacuum impregnation‐chemical precipitation method to prepare Bi 2 O 3 @TNTA composite electrodes, which were used to detect 4‐nitrophenol (4‐NP) as an electrochemical (EC) sensor. The effects of the Bi 2 O 3 loading amount and the pH value of the detection solution on the detection performance were exhaustively studied. Under best conditions, the linear range is 5 μΜ–30 mM, the sensitivity is 0.6696 μA ⋅ μM −1 ⋅ cm −2 , and the limit of detection is 0.64 μΜ. The composite electrodes are characterized by outstanding reproducibility, superior stability and strong selectivity.