Interfacial chemical bonds enhanced photocatalytic performance of kaolinite/NiFe layered double oxide heterostructure for photocatalytic activated peroxymonosulfate

Natural kaolinite is widely used in the field of photocatalysis as the support material of photocatalyst. However, its weak photochemical activity has severely limited its application as a photocatalyst in photocatalysis. Herein, kaolinite/NiFe layered double oxide (Kaol/NiFe-LDO) heterostructure photocatalyst was successfully constructed to activate peroxymonosulfate for degradation of organic pollutants. The chemical bonds formed at the interface of Kaol/NiFe-LDO heterostructures (HCs) greatly improve the photocatalytic ability of natural Kaol. Additionally, systematic characterization results validate that the Kaol/NiFe-LDO HCs possesses a direct Z-scheme band structure. By utilizing both interfacial chemical bonding and direct Z-type heterostructure effects, the optimized Kaol/NiFe-LDO HCs demonstrates a 2-fold increase in rhodamine B (RhB) degradation and a 6.5-fold increase in orange II (OII) degradation compared to natural Kaol in the presence of PMS as an oxidant. The Kaol/NiFe-LDO HCs photochemically activate the PMS to produce sulfate radicals through photo-generated hole oxidation, thus improving the photocatalytic performance of the system. The present study offers novel insights into the activation of PMS by natural clay minerals for environmental applications.