Tio2 and carbon nanotubes composites modify capacitive deionization anodes to improve the dechlorination efficiency in desulfurization wastewater

A new capacitive deionization (CDI) technology was used to remove Cl − from desulfurization wastewater. TiO 2 and carbon nanotubes (CNTs) were combined with N-methyl pyrrolidone (NMP) to form composites by a solvothermal method in which it is coated onto the CDI anode to improve dechlorination efficiency (DE). The morphology, surface area, wettability, crystal structure and chemical composition of the TiO 2 /CNTs were characterized. They showed good hydrophilicity (contact angle: 85.9°), high specific surface area (96.68 m²/g) and high specific capacitance (87.6 F/g). The experimental results illustrated that the best DE was achieved by the composites (60%T/C) under 1.2 V with the maximum electrosorption capacity toward 6.5 mg/g, and the TiO 2 /CNTs composites had excellent stability. Adsorption kinetics analysis was explored and analyzed. Furthermore, TiO 2 /CNTs composites exhibited excellent DE in actual desulfurization wastewater. The catalysis and adsorption mechanisms of the TiO 2 /CNTs anode were discussed in detail. This study provides a new direction for the application of TiO 2 /CNTs composites as adsorption materials of CDI in the Cl − of desulfurization wastewater. The TiO 2 /CNTs materials were used as adsorption materials for a CDI anode to remove Cl − from desulfurization wastewater. TiO 2 /CNTs were synthesized by using a solvothermal method based on Ti 4+ combining NMP along with CNTs as precursor solution. This study will provide a new direction for the application of TiO 2 /CNTs composite material as adsorption materials for CDI in actual desulfurization wastewater.