Shella Permatasari Santoso, Vania Bundjaja, Artik Elisa Angkawijaya, Chintya Gunarto, Alchris Woo Go, Maria Yuliana, Phuong Lan Tran-Nguyen, Chang-Wei Hsieh, Yi-Hsu Ju
Nitrogen-grafting through the addition of glycine (Gly) was performed on a metal- phenolic network (MPN) of copper (Cu2+) and gallic acid (GA) to increase its adsorption capacity. Herein, we reported a one-step synthesis method of MPN, which was developed according to the metal–ligand complexation principle. The nitrogen grafted CuGA (Ng-CuGA) MPN was obtained by reacting Cu2+, GA, and Gly in an aqueous solution at a molar ratio of 1:1:1 and a pH of 8. Several physicochemical measurements, such as Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), N2 sorption, X-ray diffraction (XRD), and thermal gravimetry analysis (TGA), were done on Ng-CuGA to elucidate its characteristics. The analysis revealed that the Ng-CuGA has non-uniform spherical shaped morphology with a pore volume of 0.56 cc/g, a pore size of 23.25 nm, and thermal stability up to 205 °C. The applicational potential of the Ng-CuGA was determined based on its adsorption capacity against methylene blue (MB). The Ng-CuGA was able to adsorb 190.81 mg MB per g adsorbent at a pH of 6 and temperature of 30 °C, which is 1.53 times higher than the non-grafted CuGA. Detailed assessment of Ng-CuGA adsorption properties revealed their pH- and temperature-dependent nature. The adsorption capacity and affinity were found to decrease at a higher temperature, demonstrating the exothermic adsorption behavior. © 2021, The Author(s).
Department of Chemical Engineering, Widya Mandala Catholic University Surabaya, Kalijudan 37, Surabaya, 60114, Indonesia; Department of Chemical Engineering, National Taiwan University of Science and Technology, No. 43, Sec. 4, Keelung Rd., Taipei, 10607, Taiwan; Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, No. 43, Sec. 4, Keelung Rd., Taipei, 10607, Taiwan; Department of Mechanical Engineering, Can Tho University, 3-2 Street, Can Tho City, Viet Nam; Department of Food Science and Biotechnology, National Chung Hsing University, No. 145 Xingda Road, South District, Taichung City, 40227, Taiwan; Taiwan Building Technology Center, National Taiwan University of Science and Technology, No. 43, Sec. 4, Keelung Rd., Taipei City, 10607, Taiwan