Modification of Cu3(BTC)2 with Cobalt Ion for Adsorption and Visualized Detection of Formaldehyde Gas

In this paper, cobalt ion was employed to modify Cu-3(BTC)(2) to improve the adsorption property for formaldehyde gas. The cobalt ion was doped during the synthesis of Cu-3(BTC)(2) to form a product of CuCo-BTC. As the optimization assay indicated, when the molar ratio of the Co2+/Cu2+ was 3/17, the adsorption amount for formaldehyde gas achieved the maximum, which is 1.6-fold to that of Cu-3(BTC)(2). ICP-MS, XPS, XRD, FT-IR, SEM and N(2)adsorption-desorption were used to investigate the structure and property of the CuCo-BTC. Subsequently, the adsorption kinetic process of the CuCo-BTC was assessed, the result suggests it coinciding to the pseudo first-order kinetic model which belongs to the physical adsorption process. The further assays indicated the CuCo-BTC possessing higher and faster colorimetric response to formaldehyde with indicator than other metal organic framework materials or common indicators. Therefore, it was utilized to fabricate a functional paper chip to perform the visualized detection of formaldehyde gas. The result displayed a sensitive response to formaldehyde gas in the concentration range of 0.02 0.08 mg/m(3). Besides, the whole colorimetric assay merely takes 150 s, suggesting a favorable application prospect in the on-site test of detrimental gas.