Platanus orientalis leaves based hierarchical porous carbon microspheres as high efficiency adsorbents for organic dyes removal

Water contamination caused by hazardous organic dyes has drawn considerable attention, among all of the techniques released, adsorption has been widely used, which however to a large degree is dependent on the development of high efficiency adsorbents. Waste biomass based porous carbon is becoming the new star class of adsorbents, and thus contribute more to the sustainable development of the society. In this work, for the first time to the best of our knowledge, abundant waste fallen Platanus orientatis leaves are employed as the raw material for hierarchical activated porous carbon (AK) microspheres via a mild hydrothermal carbonization (210 degrees C, 12.0 h) followed by one-step calcination (750 degrees C, 1.0 h). The APC microspheres exhibit a specific surface area of 135553 m(2).g(-1) and abundant functional groups such as O-H and C=O. Furthermore, the APC microspheres are used as the adsorbents for removal of RhB and MO, with the maximum adsorption capabilities of 557.06 mg.g(-1) and 327.49 mg.g(-1), respectively, higher than those of the most porous carbon originated from biomass. The adsorption rates rapidly approach to 98.2% ( RhB) and 95.4% (MO) within 10 min. The adsorption data can be well fitted by Langmuir isotherm model and the pseudo-second-order kinetic model, meanwhile the intra-particle diffusion and Boyd models simultaneously indicate that the diffusion within the pores is the main rate-limiting step. Besides, the APC microspheres also demonstrate good recydability, and may also be applied to other areas such as heterogeneous catalysis and energy storage. (C) 2019 The Chemical Industry and Engineering Society of China, and Chemical Industry Press Co., Ltd. All rights reserved.