Double-functional characteristics of a surface molecular imprinted adsorbent with immobilization of nano-TiO2

Abstract

A new chitosan molecular imprinted adsorbent obtained by immobilization of nano-TiO2 on the adsorbent surface (surface-imprinted adsorbent with nano-TiO2) was prepared. Based on photocatalytic reaction and the surface molecular imprinting technology, this new kind of surface-imprinted adsorbent with immobilization of nano-TiO2 can not only adsorb template metal ions but can also degrade organic pollutants. The results showed that, after the nano-TiO2 was immobilized on the adsorbent surface, the adsorption ability for the imprinted ion (Ni2+) of this new imprinted adsorbent immobilized with nano-TiO2 was not affected, but the degradation ability for p-nitrophenol (PNP) of the surface-imprinted adsorbent with nano-TiO2 increased three-fold compared with that of the surface-imprinted adsorbent without nano-TiO21 from 23.8 to 76.1% (at an initial PNP concentration of 20mg.dm-3). The optimal TiO2 concentration in the adsorbent preparation was 0.025 g-TiO2 g-1 adsorbent. The removal capacity for PNP reached 60.25 mg.g-1 (at 400 mg.dm-3 initial PNP concentration) under UV irradiation. The surface-imprinted adsorbent with nano-TiO2 can be reused for at least five cycles without decreasing the removal ability for PNP and the imprinted ion (Ni2+). © 2006 Society of Chemical Industry.