The Au/ZnSe/ZnO heterojunction improves the electron transfer behavior to enhance the detection performance of ascorbic acid.

The Au/ZnSe/ZnO heterojunction material with less transition zone on the two-phase interface was successfully prepared by the in-situ replacement of zinc oxide by Se2-. Moreover, the heterojunction formed by in-situ substitution can effectively reduce the interface transfer resistance and increase the life of carriers. The photocurrent of Au/ZnSe/ZnO is almost twice that of Au/ZnO, due to the formation of heterojunction ZnSe interface. As a result, the carrier lifetime of the material is increased by nearly 2.7 times (126.26 s/46.83 s) compared to Au/ZnO. Ascorbic acid is a very important compound for human metabolism, but there is no simple and rapid method to detect ascorbic acid. Au/ZnSe/ZnO is used as the photoanode of the photoelectric non-enzymatic sensor system for AA detection. The sensitivity of Au/ZnSe/ZnO/FTO-based PEC AA sensor is 113.75 μA mM−1 cm−2, exhibiting its advantages of fast, sensitive and high response. • Au/ZnSe/ZnO multi-element composite material changes the electron transport path and improves the carrier transfer. • 2. ZnSe resistance to interface recombination effectively hindered the recombination of carriers. • Enhancing the absorption of visible light, improving the carrier lifetime and forming the two-phase low interface transition zone all enhance the photoelectrochemical performance. [ABSTRACT FROM AUTHOR]