The removal of heavy metal ions in wastewater has a great significance to human health and environment protection. Metal organic framework possesses high surface area, rich porosity, tunable pore size and abundant active sites. However, the intrinsic aggregation and fragility of MOF nanoparticles make its poor adsorption and undesirable reusage. Herein, a facile and unique hot-pressing method is adopted to decorate the MOF nanoparticles on nickel foam (ZIF-8/NF), which simultaneously serves as self-supporting substrate of ZIF-8 nanoparticles and electrode of a self-powered multifunctional purification system. In adsorption, the ZIF-8/NF composite presents high Cu2+ removal rate of 49.5% with the concentration of 10 mg/100 ml. More importantly, integrating with electrochemistry, the Cu2+ removal rate of the ZIF-8/NF composite reaches 54.7% in 5 min. The superior performance is attributed to the comprehensive effects of ion exchange, chemical bonding and physical adsorption. Moreover, the low-cost, fast and scalable preparation contributes to commercially fabricate MOF nanoparticles on self-supported substrate to treat wastewater with high efficiency and good recyclability.
Yang Wang,Si Sun,Lin Shi,Pengcheng Gao,Yingying Wei,Chuan Zhang,Yong Jiang
A facile and energy-efficient synthesis of Fe 3 O 4 @SiO 2 -PHEMA complex and its application as adsorbent for removal of Cu 2+ from aqueous solution were investigated. Fe 3 O 4 @SiO 2 -PHEMA was synthesized by mixing Fe 3 O 4 @SiO 2 and HEMA monomer and then initiating the polymerization of HEMA monomer by H 2 O 2 under Fe 2+ catalyzing at room temperature . As adsorbent, the maximum sorption capacity of Fe 3 O 4 @SiO 2 -PHEMA for Cu 2+ was calculated to be 20.7 mg/g at pH 6.0. And the efficient enrichment of Cu 2+ on Fe 3 O 4 @SiO 2 -PHEMA depended on its multiple carbonyl groups and the electrostatic interaction between carboxyl groups and Cu 2+ . The carboxyl groups were from slow hydrolysis of partial ester bonds of PHEMA under acidic conditions. The possible hydrolysis process of ester bonds was facilitated to avoid sorption capacity of Cu 2+ decreasing caused by other ions sorption (like Fe 2+ ) during the synthesis of the adsorbent. The adsorption of Cu 2+ on Fe 3 O 4 @SiO 2 -PHEMA coincided with Langmuir model. The Fe 3 O 4 @SiO 2 -PHEMA had good dispersity in water and it could be easily collected from wastewaters by a magnet. The results showed that Fe 3 O 4 @SiO 2 -PHEMA was a promising adsorbent in wastewater treatment.