3D/1D heterostructure of p-BiOBr nanoflowers modified n-TiO2 nanorod arrays for highly sensitive photoelectrochemical determination of hydrogen peroxide

Hydrogen peroxide (H 2 O 2 ) is a major transmitter of redox signals during chemical processes. Cost-effective and easy-to-operate sensors for H 2 O 2 are in high demand in a variety of fields. A novel photoelectrochemical (PEC) sensor for H 2 O 2 detection was investigated, using BiOBr/TiO 2 NAs/FTO (BiOBr/TNAs) as a PEC electrode which is obtained by successive ionic layer adsorption and reaction (SILAR) method. This non-enzymatic PEC BiOBr/TNAs electrode shows excellent selectivity, stability, and reproducibility for H 2 O 2 detection in optimizing modes. The linear relationship is in a broad range from 4 to 1800 μM (R 2 = 0.994) and a detection limit of 0.65 μM (S/N = 3). In the detection of H 2 O 2 in apple juice and milk real samples, the BiOBr/TNAs show outstanding recovery ranging from 98.0 % to 102.0 %, indicating great potential in practical applications. Meanwhile, the p-n heterojunction formed between BiOBr and TiO 2 improves the utilization of visible light and effectively promotes the separation of photogenerated electrons and holes. This work provides a new strategy for the non-enzymatic detection of hydrogen peroxide in PEC mode.