Construction of heterojunction and homojunction to improve the photocatalytic performance of ZnO quantum dots sensitization three-dimensional ordered hollow sphere ZrO2–TiO2 arrays

Abstract The synergy of multiple engineering strategies is an important method for constructing highly efficient photocatalytic materials. In this work, a novel three-dimensional ordered hollow spheres (3DOHs) array TiO2 was prepared by a simple colloidal template method. The crystal structure, morphology, composition, and surface physicochemical properties of the composites were characterized by various analytical methods. The results showed that the synergy between ZnO QDs and ZrO2 was used to construct a homojunction between anatase and rutile and the heterojunction between TiO2 and ZrO2, which promoted the formation of a double-junction structure in the composite. The characterization results illustrate the existence of homojunction and heterojunction in detail, and the results of photocatalytic experiments further confirm that the 3DOHs array 0.5 ZnO QDs@ZrO2–TiO2 with homojunction and heterojunction exhibits the best photodegradation and hydrogen evolution properties. The hydrogen evolution amount is 1530 times of P25, which reaches 2573 μmol g−1 in 8 h. In summary, this work provides some new insights into the construction of highly efficient photocatalytic materials and demonstrates the generality of constructing a stable three-dimensional ordered hollow sphere array structure.