Photocatalytic antibacterial and anti-fouling technology, known for its environmentally friendly characteristics, is gaining increasing recognition for its potential applications. However, the activity of single photocatalytic materials is often limited due to the low efficiency of charge carrier separation.

To tackle this issue, a research team led by Prof. ZHANG Jie from the Institute of Oceanology of the Chinese Academy of Sciences (IOCAS) has made progress in enhancing the photocatalytic antibacterial activity of manganese (Mn) and sulfur (Sv) co-doped ZnIn2S4 (ZIS), using a novel oxygen vacancy-rich α-MnO₂ decomposition approach. This study was published in Journal of Materials Chemistry A.

The researchers employed a solid-state decomposition method of α-MnO₂, which features abundant oxygen vacancies, to successfully synthesize Mn and Sv co-doped ZIS materials. The results indicate that this solid-state decomposition method allows for a slow release of Mn elements, ensuring a more uniform incorporation of these elements into the ZIS lattice. Moreover, this doping technique enhances both the degradation and antibacterial activity of ZIS more effectively than traditional doping approaches using inorganic Mn sources.

Using Kelvin scanning probe microscopy and density functional theory analyses, the team found that the solid-state α-MnO₂ decomposition doping of ZIS results in a reduced work function. This reduction helps lower the energy barrier for photoelectrons migrating to the surface. The formation of covalent bonds between sulfur and manganese further facilitates the surface migration of photoelectrons, while the increased content of sulfur vacancies hinders the recombination of photogenerated charge carriers.

This method of solid-state decomposition doping provides a slow release of the dopant elements, leading to more uniform doping. The Mn and Sv co-doped ZIS produced through this approach incorporates multiple strategies to enhance its photocatalytic activity.

Analysis of the antibacterial performance and mechanism of enhancement of solid-state α-MnO₂ decomposition doping in ZIS. (Image by IOCAS)