Bi₂Te₃–MoS₂ Layered Nanoscale Heterostructures for Electron Transfer Catalysis

Bi2Te3–MoS2 layered heterostructures have been prepared by a hydrothermal reaction of ammonium tetrathiomolybdate with hydrazine in the presence of preformed Bi2Te3 hexagonal nanoplatelets as templates. The surface of hexagonal nanoplatelets of the topological insulator Bi2Te3 is uniformly covered with layers of metallic 1T-MoS2. Bi2Te3–MoS2 layered heterostructures exhibit high efficiency in the catalytic reduction of nitroarenes using NaBH4. The turnover frequencies (TOF) are 1.68, 1.78, 16.0, and 22.9 min–1 for 4-nitrophenol, 4-nitroaniline, nitrobenzene, and 4-chloronitrobenzene, respectively, when Bi2Te3–MoS2 heterostructure with a mole ratio of 25:75 was used as the catalyst. This catalyst could be recycled and reused over several cycles of 4-nitrophenol reduction. The enhanced catalytic activity of Bi2Te3–MoS2 layered heterostructures in comparison to pristine Bi2Te3 hexagonal nanoplatelets and 1T-MoS2 nanosheets suggests that the interfacial coupling between the topological insulator and metallic MoS2 improves the efficiency of the catalyst. Bi2Te3 with a stable supply of itinerant electrons for charge transfer for chemical reactions and high mobility electron channels coupled with catalytically active 1T-MoS2 renders the Bi2Te3–MoS2 layered heterostructure a promising catalyst for electron transfer reactions.