Facile surface modification of mesoporous silica with heterocyclic silanes for efficiently removing arsenic

Arsenic being one of the most toxic heavy metals has long been a focus of concern due to its gravest threats to human health and environment. Herein, we employ a new method named ring-opening click reaction to synthesize thiol-and amino-bifunctionalized SBA-15 (denoted as bi-SBA-15) for directly remove As(Ⅲ) without preoxidation As(Ⅲ) to As(V) from contaminated water. Quite different from commonly modified with trialkoxysilanes, ring-opening click reaction is substantially faster (0.5-2 h at 25℃) and more efficient. The synthesized bi-SBA-15 exhibits excellent adsorption performance of As(Ⅲ) and As(V) in an aqueous solution with a great adsorption capacity (33.70 mg/g and 42.66 mg/g, respectively), a very short equilibrium time (<30 min), which is much faster than those of other adsorbents reported previously. The excellent adsorption performance of bi-SBA-15 can be maintained with a wide pH range (3-8), various anions and natural organic matter, which provides an effective approach and a new insight to clean arsenic-contaminated water.