The kinetic competition between electron-hole recombination and water oxidation is a key limitation for the development of efficient solar water splitting materials. In this study, we present a solution for solving this challenge by constructing a quantum dot-intercalated nanostructure. For the first time, we show the interlayer charge of the intercalated nanostructure can significantly inhibit the electron-hole recombination in photocatalysis. For Bi2WO6 quantum dots (QDs) intercalated in a montmorillonite (MMT) nanostructure as an example, the average lifetime of the photogenerated charge carriers was increased from 3.06 mu s to 18.8 mu s by constructing the intercalated nanostructure. The increased lifetime markedly improved the photocatalytic performance of Bi2WO6 both in solar water oxidation and environmental purification. This work not only provides a method to produce QD-intercalated ultrathin nanostructures but also a general route to design efficient semiconductor-based photoconversion materials for solar fuel generation and environmental purification.