Two-dimensional heterojunction photocatalysts constructed by graphite-like C3N4 and Bi2WO6 nanosheets: Enhanced photocatalytic activities for water purification

Two-dimensional g-c(3)N(4)/Bi2WO6 heterojunction photocatalysts have been successfully synthesized by a multi-step method. Based on the structure and morphology characterization, the as-prepared photo-catalysts exhibited a nanosheet/nanosheet hybrid structure, which could provide a large heterogeneous surface area, increase the transmission route of photo-induced carriers and then suppress the charge recombination. To investigate the practical photocatalytic performance for water purification of these heterojunction photocatalysts, organic dyes such as Rhodamine B (RhB) and antibiotics including tetracycline (TC) and ciprofloxacin (CIP) have been selected as the target pollution under visible-light irradiation. The optimum photocatalyst (the weight ratio of g-C3N4 to Bi2WO6 is 1:0.67) was more than three times and two times than pure g-C3N4 and Bi2WO6, respectively. The enhanced photocatalytic activities of g-C3N4/Bi2WO6 heterojunction photocatalysts might be ascribed to the two-dimensional structure. In combination of the experiment results, the possible photo-induced charge transfer route has been detailed illustrated. (C) 2016 Elsevier B.V. All rights reserved.