Efficient adsorption-photodegradation of tetracycline hydrochloride over MoS2-MgO/S-doped biochar under solar light

Abstract

MoS2 and MgO co-modified biochar with S-doping (MoS2-MgO/S-BC) was prepared for facilitating the adsorption-photocatalysis towards tetracycline hydrochloride (TCH) elimination under solar-light irradiation. MoS2-MgO/S-BC had the better adsorption-photocatalytic activity in comparison to S-BC, b-MgO/S-BC, and 2-MoS2/S-BC, and its removal efficiency was intensively affected by MoS2 and MgO loading contents. The experimental factors such as bulk dosage, TCH concentration, inorganic salts, and pH also influenced the adsorption-photocatalytic capacity of MoS2-MgO/S-BC. The highest adsorption capacity (239.52 mg g−1) and removal efficiency (93.70 %) were obtained by optimal 2b-MoS2-MgO/S-BC for 200 mg/L TCH solution within 120 min. The adsorption process of MoS2-MgO/S-BC was well described by Langmuir isotherm and second-order model. The boosted adsorption-photocatalytic performance of MoS2-MgO/S-BC in TCH removal was ascribed to the abundant vacant sites generated from the functional groups of S-doped biochar and lattice defects of MoS2 and MgO, and the efficient separation and migration of photoinduced e-/h+ at the junction interface among MoS2, MgO, and S-BC.