<scp>pH</scp>‐Responsive Polymer Coated Sponge With Self‐Cleaning Ability for Controllable Adsorption of Dyes

ABSTRACT Constructing a novel functional adsorbent with optimized adsorption/desorption processes and smart recycling performance is of great significance for sewage treatment. Here, a functional melamine sponge (F‐MS) capable of controllable adsorption of methylene blue was prepared. The inherent microporous polymer modified with hydroxylamine (AOPIM‐1) has a porous structure that can provide plentiful adsorption sites, and its acyl oxime groups have a strong pH‐responsive electrostatic effect for promoting the performance of adsorption/desorption. Moreover, F‐MS can superfast adsorb methylene blue, achieving 50% adsorption efficiency in 2 min and reaching adsorption equilibrium within 30 min with a maximum adsorption capacity of 1229 mg/g. By adjusting pH values from 12 to 3, F‐MS can desorb MB by over 97% in 10 s, and the efficiency after multiple cycles still exceeds 95%. Thus, during the daytime, self‐cleaning of the pores can be achieved, ensuring efficient recycling under visible light; at night, the process can effectively conduct by adjusting the pH of the environment. Therefore, F‐MS can work continuously regardless of day or night. This construction strategy is expected to be applied to the treatment of sewage with severe dye pollution in the future.