Piezoelectric Persulfate Activation Process for Oxidative Degradation of Aqueous Pollutants

The sulfate radical-based advanced oxidation process (SR-AOP) is a very powerful tool that generates powerful sulfate radicals and the associated active oxidizing species for the refractory organic degradation and sterilization. Recently, piezocatalysis is a viable green and sustainable technology because of its capacity to passively convert mechanical energy into electrochemical energy making it an efficient technology for environmental remediation. Since the conventional piezocatalytic driven advanced oxidation process (Piezo-AOPs) in which hydroxyl (⋅OH) radicals serve as the main oxidant, the primary application of classical piezocatalysts is the decomposition of various dye molecules, which more readily than other electrons rich pollutants and pharmaceutical pollutants. Concerning phenolic and pharmaceutical pollutants, piezocatalytic sulfate radical-based advanced oxidation process (piezocatalytic SR-AOPs) which synergizes the inherent benefits of SR-AOPs with piezoelectric materials has become a promising technique in recent years. Therefore, the present review focuses closely on various types of piezoelectric catalysts, the involvement of piezoelectric effect in activation of persulfate oxidants, different sources of mechanical energy, their proposed radical pathways, and effectiveness in oxidative aqueous pollutants degradation.