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Groundwater containing naturally occurring uranium is a conventional drinking water source in many countries. Removal of low concentrations of uranium complexes in groundwater is a challenging task. Here, we demonstrated that the TiO2 nanotube arrays/Ti (TNTAs/Ti) mesh electrode could break through the concentration limit and efficiently remove low concentrations of uranium complexes from both simulated and real groundwater. U­(VI) complexes in groundwater were electro-reduced to UO2 and deposited on the TNTAs/Ti mesh electrode surface. The adsorption rate and electron transfer rate of the anatase TNTAs/Ti mesh electrode were twice that of the rutile TNTAs/Ti mesh electrode. Therefore, the anatase TNTAs/Ti mesh electrode exhibited excellent electrocatalytic activity toward the electrochemical removal of U­(VI), which could work at a higher potential and significantly reduce the energy consumption of U­(VI) removal. The U­(VI) adsorption capacity on the anatase TNTAs/Ti mesh electrode was limited due to the low U­(VI) concentration. However, the anatase TNTAs/Ti mesh electrode displayed a huge U­(VI) removal capacity using the electroreduction method, where adsorption and reduction of U­(VI) were mutually promoted and induced continuous accumulation of UO2 on the electrode. The accumulated UO2 can be easily recovered in dilute HNO3, and the electrode can be used repeatedly.

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