Rationalizing high-entropy catalytic self-Fenton pollutant degradation from an effective porous piezoelectric composite film

As an emerging catalytic strategy, heterogeneous Piezo-Self-Fenton (EPSF) has demonstrated significant potential in fields such as environmental remediation and biomedicine in recent years. However, the catalytic reactions in this process are complex and diverse, and the understanding of high-entropy catalytic systems remains limited. In this study, we constructed a series of iron-based EPSF materials by incorporating various types of iron sources into MgO@rGO/PVDF-HFP composite piezoelectric films. The findings indicated that the type of iron source remarkably influences the EPSF efficiencies. Notably, the Fe3O4-doped composite films exhibited excellent EPSF outcome. Three factors contribute to their high performance, which are high adsorption towards a range of organic pollutants, superior conversion efficiency to generate a specific type of reactive oxygen species (ROS) ˙O2-, and favorable pollutant solution pH for the reaction. The MgO@rGO@Fe3O4/PVDF-HFP composite combines these features, enabling sustained degradation activity in mixed pollutant environments. This study offers valuable insights into obtaining high catalytic performance in pollutant degradation in reality-mimicking high-entropy systems, where both the types of ROS involved and the existing types of pollutants are multiple.