A facile one-step synthesis of super-hydrophilic (NH4)0.33WO3/WS2 composites: a highly efficient adsorbent for methylene blue

Abstract

Super-hydrophilic ammonium tungsten bronze/tungsten disulfide composites ((NH₄)_0.33WO₃/WS₂, ATBDs) were synthesized successfully using a one step hydrothermal method. They have super-hydrophilic properties, and the contact angle is 0 degree. (NH₄)_0.33WO₃/WS₂ composites showed the morphology of nanorods with a diameter of approximately 50 nm and a length of a few microns. Less than 2 min was required to attain more than 80% of the maximum adsorption capacity (MAC, 80.45 mg g⁻¹) and 10 min was required to attain 95% of the MAC in methylene blue aqueous solution. η (adsorption capacity in unit time, mg (g min)⁻¹) was defined to further describe the adsorption capacity of the adsorbent. A high η value represents a high quality adsorption behavior, and the adsorbent has a η value of up to 8.045. The special structure, strong electrostatic interactions and super-hydrophilic properties lead to the high adsorption quality of ATBDs toward methylene blue.