Microwave-assisted preparation of mesoporous-activated carbon from coconut (Cocos nucifera) leaf by H3PO4activation for methylene blue adsorption

作者：Ali H. Jawad, Sumiyyah binti Sabar, Mohd Azlan Mohd Ishak, Lee D. Wilson, Siti Solehah Ahmad Norrahma, Mahesh Kumar Talari, Ahlam Mohammed Farhan · 发表于：Chemical Engineering Communications · 年份：2017 · DOI：10.1080/00986445.2017.1347565 · 被引用次数：124 · 研究领域：Adsorption and biosorption for pollutant removal、Supercapacitor Materials and Fabrication、Carbon and Quantum Dots Applications

Mesoporous-activated carbon was prepared from fallen coconut (Cocos nucifera) leaf, an agricultural waste through a microwave-induced H3PO4 activation process. The characterization of the coconut leaf–activated carbon (CAC) was evaluated through the iodine number, ash content, bulk density, and moisture content. Fourier transform infrared spectroscopy, scanning electron microscope, Brunauer–Emmett–Teller (BET) surface area, X-ray diffraction, and pHPZC. CAC has a mesopore content of 84% with an average pore size of 36.5 Å and a large BET surface area of 632 m2/g. The uptake properties of the CAC with methylene blue was evaluated at different CAC dosage levels (0.2–10 g/L), initial pH (3–10), methylene blue concentration (50–350 mg/L), and time (0–360 min) using batch mode operation. The kinetic profiles were described by the pseudo-second-order kinetics. The equilibrium data were well fitted to the Langmuir model with a maximum monolayer adsorption capacity of 250 mg/g at 30°C. Thermodynamic functions indicate a spontaneous and exothermic nature of the adsorption process. This study indicates that coconut leaves are a promising renewable precursor that can be utilized to develop an efficient mesoporous-activated carbon.