Successfully inducing lattice distortion in BiOCl hierarchical nanoflowers through defect engineering for enhanced photocatalytic activity

Inducing lattice distortion via defects engineering is an effective strategy to enhance photocatalytic activity. In this study, the BiOCl photocatalyst is successfully prepared by the co-precipitation method. The hierarchical nanoflower structure is designed by the co-modification of PEG-2000 and HNO₃. The oxygen defect concentrations in BiOCl could be accurately controlled within the range of 32.13–46.98 %. It is noteworthy that the variation in oxygen defect concentration is intimately associated with the degree of distortion on the (001) crystal plane in BiOCl. The photocatalytic results indicates that the Cr(VI) reduction efficiency and MB degradation efficiency of BiOCl-1 with an oxygen defect concentration of 37.12 % were 4.15 times and 5.95 times higher than those of pure BiOCl. It is discovered that the oxygen defects generated by adjusting the concentration of HNO₃ could capture photogenerated electrons, thereby enhancing the light absorption efficiency. The designed hierarchical nanoflower structure could enhance the utilization efficiency of light. The optimal distortion intensity of the (001) crystal plane regulated by oxygen defects could shorten the bandgap and enhance the carrier separation efficiency of BiOCl. This innovative strategy offers new insights for designing efficient photocatalysts for the removal of heavy metal ions and organic pollutants.