A novel flower-like MnO₂ nanowires for rapid removal of methylene blue

In order to enhance the adsorption property of adsorbent, surface modification of existing adsorption materials has always been an interesting and challenging topic. Herein, the flower-like MnO₂ nanowires (MNs) with three dimensions surface area and great adsorption property was successfully prepared by two-step hydrothermal route via MnO₂ nanosheets in-situ growth on MnO₂ nanowires. As an adsorbent, the MNs was evaluated for the removal of methylene blue (MB) from the aqueous solution. The effect of pH value, contact time, adsorbent dose, adsorption equilibrium, kinetics adsorption process, and isothermal models was investigated. The results showed that the maximum adsorption capacity of MNs of 2 g/L attained 34.247 mg/g at 5 minutes, and kinetics of MB were found fitting using the Langmuir model and the pseudo-first-order model, respectively. Furthermore, the adsorption capacity can be kept over 90% after five adsorption cycles. Therefore, the composite material can be a promising tool for developing a large variety of efficient and stable adsorbents by combining with different nanostructures for dyeing wastewater treatment.