Adsorption and photocatalytic degradation of tetracycline hydrochloride using a palygorskite-supported Cu2O–TiO2 composite

A palygorskite (Pal)-supported Cu 2 O–TiO 2 heterojunction composite (Cu 2 O–TiO 2 –Pal) was successfully prepared. The morphology, structure and chemical composition of the composite was characterized, and the adsorption and photocatalytic degradation of tetracycline hydrochloride using this composite was also investigated. The results showed that a layer of TiO 2   −   Cu 2 O was successfully loaded on the surface of Pal. The Cu 2 O–TiO 2 –Pal composite had a specific surface area of 93 m 2 ·g −   1 , mesoporous features, and a uniform slit channel. The composite possessed twofold removal ability to TC, including adsorptive capability for the separation and solar-light illuminate photocatalytic in degradation. The maximum adsorption capacity of Cu 2 O–TiO 2 –Pal for TC was 113.6   mg·g −   1 at 20   °C as calculated by the Langmuir model. The pseudo-first-order degradation rate constant of 50   mL of TC with an initial concentration of 30   mg·L −   1 reached 0.0129   min −   1 when the Cu 2 O–TiO 2 –Pal concentration was 1.0   g·L −   1 . The total removal rate of TC reached 88.81% in the presence of Cu 2 O–TiO 2 –Pal. In addition, the composite could be regenerated by calcination at 400   °C and recycled more than three times, which is useful for practical applications.