A novel nano-sized MoS2 decorated Bi2O3 heterojunction with enhanced photocatalytic performance for methylene blue and tetracycline degradation

Abstract

In this paper, MoS 2 was used as a band-suitable semiconductor to construct the Bi 2 O 3 /MoS 2 heterostructured photocatalysts for the first time via a deposition-hydrothermal method. The XRD, SEM and HRTEM analysis indicated that the surface of Bi 2 O 3 was decorated with MoS 2 nanoparticles and Bi 2 O 3 /MoS 2 heterojunctions were formed. The performances on photocatalytic degradation of methylene blue (MB) and tetracycline (TC) were evaluated under visible light irradiation. The results demonstrated that the Bi 2 O 3 /MoS 2 heterojunctions displayed remarkably improved photocatalytic activity for both MB and TC degradation, compared to the base material (Bi 2 O 3 ). Specifically, as the molar ratio of MoS 2 was 23.81%, the obtained Bi 2 O 3 /MoS 2 -23.81 heterojunctions exhibited promising photocatalytic activities, and approximately 100% MB and 97% TC were degraded within 100 min, respectively. The superior photocatalytic activity was mainly attributed to its large surface area, high visible-light harvesting and the efficient separation of photogenerated electrons and holes caused by the unique heterojunction architecture. Notably, the Bi 2 O 3 /MoS 2 heterojunctions showed remarkable stability in recycling photocatatlytic experiments. The active species trapping and terephthalic acid (TA) fluorescence experiments indicated that the •OH was the major reactive oxidizing species for MB degradation. Furthermore, the intermediates were detected by UPLC-MS spectrometry and the possible degradation pathways for MB and TC were proposed. Finally, a possible reaction mechanism of Bi 2 O 3 /MoS 2 heterojunctions for the photodegradation MB was also proposed. This interesting interfacial architecture strategy will provide useful insights for designing and fabricating new class of binary heterojunctions with high-efficient photocatalytic activity towards practical application. A highly efficient visible-light responsive photocatalyst Bi 2 O 3 /MoS 2 heterojunctions was prepared for the organic dyes and antibiotic pollutants elimination. • Bi 2 O 3 /MoS 2 heterojunction was prepared by deposition-hydrothermal method. • Bi 2 O 3 /MoS 2 -23.81 exhibited enhanced photocatalytic activity than that of pure Bi 2 O 3 . • The electrons transfer and visible-light harvesting effects were obviously improved. • The ⋅OH was the main oxidative species of Bi 2 O 3 /MoS 2 -23.81 for the MB decomposition.