Synchronously enhanced photothermal properties and mass transfer photothermal membrane distillation (PMD) by using Ag-modified Ti3C2Tx armored UiO-66-NH2 towards sustain water production

To solve the freshwater dilemma, photothermal membrane distillation (PMD) has become a promising and sustainable method for desalination and wastewater purification. Ti 3 C 2 T x has attracted much attention in the field of Janus PMD membrane preparation due to its hydrophilic surface and high photothermal conversion efficiency. However, the shortcomings of easy stacking and surface light reflection limit its application. In this work, electrostatic adsorption self-assembly between Ti 3 C 2 T x and UiO-66-NH 2 by pH adjusting is designed, and the Ag-modified Ti 3 C 2 T x aims to significantly improve the photothermal conversion efficiency-Ag@Ti 3 C 2 T x /UiO-66-NH 2 membrane. Compared to the origin Ti 3 C 2 T x membrane, the photothermal layer containing UiO-66-NH 2 contributes to the unimpeded transport of water, and this 3D photothermal layer structure can maximize the capture and absorption of light, which contributes to enhanced high light absorption, photothermal conversion ability and more efficient mass transfer. Thus, a consistently high vapor flux of 1.13 kg/m 2 h and photothermal efficiency over 77.3 % were synchronously obtained, under one solar irradiation. Specifically, Ag@Ti 3 C 2 T x /UiO-66-NH 2 membrane meanwhile exhibits commendable water permeate production and high stability in anti-scaling tests, as well as reliable physical stability, which offers great application potential in PMD process. Our work provides a novel strategy for constructing PMD membrane with stably enhanced mass transfer and photothermal properties to satisfy real application.