Mixed‐Dimensional Membranes with Double 0D@2D Structures Enable Efficient and Sustainable Water Treatment

High‐efficiency and sustainable membrane purification technology is highly desirable but unattainable in the field of water treatment. 2D materials are emerging as very promising candidates for water treatment applications. However, membranes assembled by pure 2D materials lack reasonable structural and functional design, usually exhibiting relatively low water permeance, purification performance, and fouling resistance. Here, a mixed‐dimensional membrane is designed to solve the above‐mentioned problems by assembling two kinds of in situ grown 0D@2D functional building blocks of SiO 2 @GO and TiO 2 @MXene. Specifically, the obtained membrane exhibits high and maintainable water permeance of 2114 L m −2 h −1 bar −1 as well as high rejection rates toward organic dyes thanks to the plentiful firm water channels constructed by 0D@2D structures and the negative charges on both SiO 2 @GO and TiO 2 @MXene, respectively. Moreover, the 0D@2D TiO 2 @MXene serves as photocatalyst, rendering the composite membrane intriguing self‐cleaning function under UV irradiation, which is verified by the high recovery ratios of water permeance (97.5%) and dye interception rate (98.7%). Thus, this work offers a promising approach for the design of highly efficient and sustainable membrane for separation and purification purposes.