UV-light-induced photocatalytic performance of reusable MnFe-LDO-biochar for tetracycline removal in water

Abstract

A high-efficiency layered double oxide-biochar hybrid (MnFe-LDO-biochar) catalyst was successfully synthesized by the co-precipitation-calcination process and used to effectively remove tetracycline (TC) pollution. The characterization results verified that MnFe-LDO-biochar possesses a specific surface area of 524.8 m(2) g(-1), appropriate bandgap (2.85 eV), a high photocurrent response (3.8 mu A cm(-2)), a saturation magnetization of 28.5 emu g(-1) and a mixture of interconnected pores. 40 % of TC was removed after 30 min when 50 mL TC solution (20 mg L-1) was treated with 50 mg MnFe-LDO-biochar in the dark and reached-98 % degradation rate within 240 min upon exposure to a UV light. Notably, in the presence of H2O2 or K2S2O8, the degradation rate of MnFe-LDO-biochar was shortened to 60 min with an average pseudo-first-order rate constant of 0.0445 min(-1). The antibiotic removal rate of the cost-competitive MnFe-LDO-biochar surpassed several reported materials and maintained-80 % reuse efficiency after 3rd successive cycles. The TC photodegradation mechanism is multi process induced majorly by center dot OH and center dot SO(4)while h+ and center dot O(2)contributed partly to the mineralization. This work highlights the powerful synergistic combination of layered double oxide (LDO) and biochar.