Fabrication of piezo-phototronic effect enhanced photocatalytic coating based on ZnO/BiOCl and its degradation performance

The degradation efficiency of photocatalysts is severely restricted by the rapid recombination of photogenerated carriers. To solve this problem, ZnO/BiOCl nanocomposites with piezo-phototronic effect were successfully prepared. The results show that the piezo-phototronic effect–enhanced photocatalytic degradation efficiency of ZnO/BiOCl-1:4 can be increased by 2.00 times compared with the degradation efficiency under only light condition, confirming the effectiveness of piezo-phototronic effect–enhanced photocatalytic performance. Subsequently, ZnO/BiOCl nanocomposites were coated on the surface of cement-based materials with polydimethylsiloxane as the matrix. It can be found that with the increase of the amount of BiOCl, the dispersion is significantly improved. Due to the addition of nanomaterials, the hydrophobic properties of the coatings are improved to a certain extent, but the adhesion strength decreased slightly. Noteworthy, the piezo-photocatalytic cement-based material coating based on ZnO/BiOCl nanocomposites can only degrade 45.4% of methylene blue for 5 h under light condition, but can degrade 81.1% for 100 min under ultrasound and light conditions. Therefore, the piezo-phototronic effect enhanced photocatalytic coating based on ZnO/BiOCl can improve the degradation ability of organic pollutants on cement-based materials’ surface, which provides an effective method for the inevitable corrosion problems facing structures of cement-based materials.