Iron and 1,3,5-Benzenetricarboxylic Metal–Organic Coordination Polymers Prepared by Solvothermal Method and Their Application in Efficient As(V) Removal from Aqueous Solutions

Iron and 1,3,5-benzenetricarboxylic (Fe–BTC) metal–organic coordination polymers are synthesized via a simple solvothermal method. The as-synthesized Fe–BTC polymers exhibit gel behavior, which is stable in common organic solvents or in water. The Fe–BTC polymer as an adsorbent for arsenic removal from water is tested. The kinetics and thermodynamics of arsenic adsorption by the Fe–BTC polymer in aqueous solution are investigated comprehensively. The effect of pH on the adsorption is also investigated. Kinetic studies show that the kinetic data are well described by the pseudo-second-order kinetic model. The thermodynamic analysis indicates that the adsorption is spontaneous. The adsorption isotherms can be well described with the Langmuir equation. The Fe–BTC polymers show relatively high arsenic adsorption capacity, more than 6 times that of iron oxide nanoparticles with a size of 50 nm and 36 times that of commercial iron oxide powders. Hence, the as-synthesized Fe–BTC polymers possess relatively high stability and better adsorption characteristic than nanomaterials simultaneously. It also can be considered as a new method to conquer the dilemma between the excellent properties from nanoscale effect and the aggregation of small size particles in the adsorption application of nanoparticle materials.