Enhanced Water Purification via Redox Interfaces Created by an Atomic Layer Deposition Strategy

The crisis of water scarcity has become one of the most urgent issues to be settled. It is still a challenge to develop a highly efficient water purification technology. In this work, highly efficient capacitive removal of metal ions from wastewater was demonstrated by using Ti–C redox interfaces created by an atomic layer deposition (ALD) strategy. It has been illustrated that the TiO2 nanolayer was formed by reaction on the surface of porous carbon (PC) by using an ALD strategy, which could effectively build the Ti–C redox interfaces; and thus, the TiO2 nanolayer on PC was beneficial for facilitating ion diffusion/transmission and adsorption/insertion. Impressively, this process showed a deionization capacity of 38.54 mg g−1 in a 500 mg L−1 NaCl solution at 1.2 V. In addition, this process had excellent capacitive removal efficiency to treat complicated water containing multiple metal ions (K+, Mg2+, Ca2+, Ni2+, Co2+, Cu2+, Pb2+, Cd2+, Cr2+, Fe3+ and Al3+). This work has important practical implication for highly efficient removal of metal ions from wastewater.