Interfacial Chemical-Bond-Modulated Charge Transfer of Heterostructures for Improving Photocatalytic Performance

Interface engineering of heterostructured photocatalysts plays a very important role in the transfer and separation process of interfacial charge carriers, but how to regulate the transfer and separation of photogenerated charge carriers still is a huge challenge at the nanometric interface of heterostructures (HCs). Herein, we demonstrate that interfacial chemical bonds can effectively modulate photogenerated charge transfer in nanoclay-based HCs constructed by natural Kaolinite (Kaol) nanosheets and P25-TiO₂. Experimental results and density functional theory (DFT) calculations confirm that stable Al-O-Ti bonds form at the interfaces by interactions of the Al-OH groups of Kaol and (101) surfaces of anatase TiO₂. The Al-O-Ti bond strengthens the energy band bending of the space charge region near the interfacial bond and thus provides a fast transfer channel for interfacial photogenerated charge, resulting in the boosted charge transfer and separation ability of Kaol/P25 HCs. The findings reported here provide a deeper insight into modulating interfacial charge transfer by chemical bonds and shed new light on interface engineering of efficient heterostructured photocatalysts for environmental applications.