Robust Redox-Active Hydrogen-Bonded Organic Framework for Rechargeable Batteries

The problems such as low cycle stability, poor ion mobility and weak conductivity hinder the development of organic electrode materials. Herein, one of robust porous hydrogen-bonded organic framework (HOF), CPHATN-1a,...

The Enhanced Effect of Bicarbonate Anion for the Removal of 2,4-Dichlorophenoxyacetic Acid on a Palladium/Nickel-Foam Electrode

Palladium/nickel-foam (Pd/Ni) electrode is used as a typical efficient electrocatalytic electrode for the removal of 2,4-dichlorophenoxyacetic acid (2,4-D) in surface water and industrial wastewater. Many researches had reported how to enhance the dechlorination efficiency of the Pd/Ni electrode by using less Pd loading. However, there are few reports of choosing a suitable electrolyte solution to improve the efficiency of dechlorination. Efforts were made in this work of the different catholyte influenced the dechlorination efficiency. The results showed the fastest removal efficiency of 2,4-D in 34 mmol/L NaHCO3 than in 34 mmol/L NaCl, 34 mmol/L NaClO4, 17 mmol/L Na2SO4 catholyte, respectively on Pd/Ni electrode with pd loading of 0.202 mg/cm2 at constant potential of -0.55 V (vs saturated calomel electrode). The dechlorination current efficiency (CE) was 20.5% in the 34 mmol/L NaHCO3 catholyte more than three times that in 17 mmol/L Na2SO4 catholyte for that HCO3- was the most likely source of protons for adsorbed active hydrogen (H*) in Pd active centers.

Electrochemical Dechlorination of 3-chlorophenol with Palladium-Loaded Carbon Felt Electrode

Electrochemical dechlorination with Pd-loaded electrodes offers an effective method for detoxification of wastewater. Electro-reductive dechlorination of 3-chlorophenol (3-CP) with Pd loaded on carbon felt (Pd/CF) was investigated. Pd was loaded on carbon felt by electrolytic method. The prepared electrodes were characterized by XRD, SEM, EDS, S-TEM and CV. The sizes of the Pd particles loaded on CF were found in the range of 100–400 nm. The preparing conditions including loading amount of Pd and loading currents were investigated. Moreover, the reduction conditions including electrolytes, reductive currents and recycle times were also studied. The Pd/CF cathodes with Pd loading of 0.5 mg/cm2, preparing current of 5 mA, electrolyte concentration of 30 mmol/L NaCl and 30 mmol/L CH3COONa were used to reduce 3-CP for dechlorination. When CH3COONa was used as the electrolyte, the current was 5 mA, the initial pH was 7.5, the initial 3-CP concentration was 1 mmol/L and the degradation rate of 3-CP could reach 95.81% after reduction of 150 min under an argon atmosphere. The electrochemical reduction of 3-CP was confirmed to follow the first-order rate law. 3-CP was qualitatively dechlorinated to phenol on electrodes with Pd. The fact that active hydrogen formed on palladium during preliminary electrolysis could be proved by the dechlorinated 3-CP in non-electroreduction after preliminary electrolysis. A possible reduction pathway was proposed based on the results.