Tightly-coated and easily recyclable Ag@AgBr-cotton hybrid photocatalyst for organic dye degradation under visible light

Immobilization of photocatalysts on substrates is an important factor for water purification in practical applications. In this study, an efficient Ag@AgBr photocatalytic coating was attached onto the surface of cotton fabric via radiation-induced graft polymerization and subsequent chemical reactions, and the resultant product was denoted as Cot-Ag@AgBr. The graft chains acted not only as a source of bromine, but also as an intermediate layer to anchor the Ag@AgBr photocatalytic coating via strong electrostatic interactions. The immobilized Ag@AgBr photocatalytic coating exhibited outstanding photocatalytic properties for organic dye degradation under visible light irradiation. Furthermore, Cot-Ag@AgBr presented high stability and robust durability, which conferred its excellent visible-light-driven photocatalytic activity after five rounds of photodegradation. After 10 min of ultrasonication, the amount of Ag@AgBr precipitate that leached from the Cot-Ag@AgBr was < 2%. Therefore, the as-synthesized cotton fabric offered good insight into the functionalization of polymer substrates with photocatalysts and could be useful for advanced wastewater treatment under the cyclic operations.