▎ 摘　　要

Reduced graphene oxide (rGO) was prepared via a green reduction method by using Annona muricata leaves extract as bioreductor. The preparation was conducted by studying the effect of time of reduction on physicochemical feature and adsorption capability of rGO towards methylene blue. A variety of spectroscopic and analytical techniques, consist of Fourier-Transform infra-red, X-ray diffraction, scanning transmission electron microscopy, and transmission electron microscope were employed to characterize the physical properties of adsorbent. It is found that by varied time of reduction (4, 12 and 24 h), the longer time of reduction, the higher reduction efficiency and specific surface area of rGO obtained, which linearly correlated with the increasing adsorption capability towards methylene blue. The adsorption obeys pseudo-second order kinetics and follow the Langmuir isotherm as representation of the chemisorption mechanism over homogeneous surface of adsorbent. The high adsorption capability of material reaches similar to 99% at 30 min of adsorption, suggests that the bioreduction method in this work is a potential method for reduced graphene oxide synthesis.