Effect of MgO Surface Modification on the TiO2 Nanowires Electrode for Self-Powered UV Photodetectors

TiO2-based core–shell structure has gained enormous significance and has developed as a promising candidate in photoelectrochemical (PEC) devices due to its excellent properties. Despite studies, the surface/interface chemistry in these nanostructures has not been fully understood and there is still much room to further improve the performance of related PEC devices. Here, using a closely integrated experimental investigation and mechanism analysis, we scrutinized the intrinsic role of the MgO coating in the photocurrent enhancement of TiO2@MgO core–shell structured UVPDs. We evidenced that after coating with MgO, the photocurrent of UVPDs has been significantly enhanced and the optimal coating time was found to be 45 min. A large responsivity of 365 mA W–1 at 360 nm and a simultaneously excellent on/off ratio of 16 739 are achieved, which have rarely reported previously. In addition, the structure–property relationships are well established in all studied UVPDs through comparing investigations. The super...