Afterwards, the activated products were cooled at room temperature under a flow of nitrogen gas, refluxed with ethanol
(95%, V/V) for several hours and washed with hot deionized water in ultrasonic device to remove remaining chemical until the pH of the washing solution reached 6–7 and free of detectable inorganic ion. After dried in vacuumdryer at 110 °C for 4 h and cooled to roomtemperature, finally the obtained bamboo activated carbons were sieved in the size range of 0.2–0.3 mm and stored in desiccator.