Solar-Driven Interfacial Evaporator with a Self-Powered Detector Based on the Gr@Ti4O7:Eu3+,Yb3+ Fibrous Membrane

Interfacial evaporation is energy-efficient to alleviatethe freshwaterissues by utilizing the renewable and inexhaustible solar energy.Herein, a fibrous photothermal membrane of Gr@Ti4O7 doped with Yb3+ and Eu3+ was preparedby electrospinning, which presented high photothermal conversion efficiency(96.01%), an outstanding evaporation rate (1.82 kg & BULL;m(-2)& BULL;h(-1)), and a remarkable salt rejection rate(99.997%). These results demonstrated that the combination of Ti4O7, graphene, and rare earth elements achievedphotothermal synergy and surpassed a majority of photothermal materialsconstructed by semiconductors. In addition, based on the biomimeticconcept of unidirectional water transfer through trees, a self-monitoringfunction was achieved using asymmetric hydrophobic modification andan electrical signal of 802 mV was obtained. This work not merelyprovided valuable prospects for its application in seawater desalinationbut also discovered a new function for self-monitoring of the evaporationprocess. Schematic diagram of the processof evaporating seawaterby photothermal conversion and generating electrical signals basedon the hydrovoltaic effect.

Automated summary

In this study, a fibrous photothermal membrane was prepared by electrospinning, which achieved high photothermal conversion efficiency, remarkable evaporation and salt rejection rates. The combination of Ti4O7, graphene, and rare earth elements exceeded the performance of most photothermal materials constructed by semiconductors. Furthermore, the membrane achieved a self-monitoring function based on the biomimetic concept of unidirectional water transfer through trees.