Clew-like Cu<sub>2</sub>O/CuO Microsphere Adsorbents for Highly Efficient Anionic Dye Removal
Shuyu Wang, Xiaohui Wu, Lijuan Ren, Xian Pei, Hui Fang, Ping Lv, Ning Nan, Xian‐Wei Lv, Xianming Zheng, Feihe Ma, Yun Wu, Yuping Liu, Linqi Shi
Abstract
Adsorbents with high selectivity and adsorption capacity are of significant interest for the removal of dye pollutants. Herein, we report a facile low-temperature solvothermal synthesis of clew-like Cu 2 O/CuO microspheres by using cupric acetate monohydrate as the copper resource and ethylene glycol as the solvent and morphology modulator. The synthesized Cu 2 O/CuO microspheres showed high selective adsorption to anionic dyes (e.g., methyl orange (MO) and Reactive Red 2 (RR2)) rather than to cationic dyes (e.g., methylene blue (MB), Rhodamine B (RhB)). MO was then selected to evaluate the parameters of adsorption due to the adsorbent exhibiting the highest adsorption capacity for MO. We demonstrate that the adsorption of MO by Cu 2 O/CuO microspheres has a good correlation with the pseudo-second-order model and Langmuir isotherm with a maximum adsorption capacity of 826.45 mg/g, which is higher than that of previously reported metal oxide material adsorbents. The excellent adsorption ability of clew-like Cu 2 O/CuO microspheres to MO may be attributed to the synergistic effects of electrostatic attraction, unique hierarchical structure, and crystal defects of the prepared Cu 2 O/CuO microspheres. We believe our work provides new insight into the synthesis of high-performance adsorbents.