FeIIAlIII layered double hydroxide modified carbon-felt cathode for efficient electrochemical reduction of bromate

Bromate (BrO3-) is harmful to human health and may cause cancer. In this work, a novel carbon felt cathode modified by (FeAlIII)-Al-II-layered double hydroxide ((FeAlIII)-Al-II-LDH/CF) was synthesized in a facile manner for effective reduction of BrO3-. The effects of operational parameters such as hydrothermal time, initial solution pH, applied current, dissolved oxygen (DO), and initial BrO3- concentration were investigated. Particularly, the (FeAlIII)-Al-II-LDH/CF electrochemical reduction system can remove 100% of BrO3- (1.2 mu M) within 75 min and completely adsorb the reduced Br- ions at a current strength of 10 mA. As the initial BrO3- concentration increased, the treatment time for complete removal of BrO3- only needs to be prolonged accordingly, and the Br- ions exceeding the adsorption capacity would be released into the solution. The electrocatalytic reduction of BrO3- could be achieved under a wide range of DO and pH conditions, and the lower DO and moderate pH were more favorable. Mechanism studies revealed that electrocatalytic reduction of BrO3- was mainly achieved by (FeAlIII)-Al-II-LDH, and electrons from the cathode allowed (FeAlIII)-Al-II-LDH to be regenerated efficiently. The (FeAlIII)-Al-II-LDH/CF electrode can be well preserved in air and had a stable cycling performance. It is the first time that a (FeAlIII)-Al-II-LDH based electrode was used in the field of electrocatalytic reduction of bromate. To conclude, (FeAlIII)-Al-II-LDH/CF cathode holds great promise in the area of water purification for bromate removal.

Automated summary

In this work, a novel carbon felt cathode modified by (FeAlIII)-Al-II-layered double hydroxide ((FeAlIII)-Al-II-LDH/CF) was synthesized for effective reduction of harmful bromate. The modified cathode showed excellent performance in removing bromate, with complete removal achieved within a short period of time. The electrocatalytic reduction of bromate was mainly achieved by (FeAlIII)-Al-II-LDH, which allowed efficient regeneration of the material. The (FeAlIII)-Al-II-LDH/CF cathode holds great promise in the area of water purification for bromate removal.