Catalytic Application of Few Layer MoS2

Catalytic Application of Few-Layer MoS 2

*Ryan Dekle, **Swagotom Sarkar, **Hongmei Luo,* Sanchari Chowdhury

*New Mexico Tech, **New Mexico State University

The reduction of 4-Nitrophenol by sodium borohydride is studied as a model reaction to test the

catalytic activity of defect free and defect rich annealed and non-annealed few-layer MoS 2 . With

increasing demand for 4-nitrophenol and its derivatives, as raw materials for agrochemicals,

dyes, drugs, polymers, rubbers and different natural products, the reduction and removal of 4-

nitrophenol has drawn extensive attention in recent years. This reduction is often considered as a

benchmark reaction to test a catalyst nanoparticle and the progress of the reaction can be

conveniently monitored by UV-visible spectrophotometry. We observed at room temperature,

there is negligible reduction with NaBH 4 only. However in the presence of MoS 2 the reaction is

quite efficient. Defect free few layer MoS 2 have shown efficient catalytic activity towards 4-

Nitrophenol reduction. Since hydrothermally synthesized few layer MoS 2 does not show 1T

phase, the catalytic activity can be attributed to its metallic edge. Defects such as vacancies are

usually expected to be active centers for molecular adsorption and chemical reaction and often

more catalytic sites can be activated by introducing sulphur (S) vacancies. However in our case

the defect rich samples show lower catalytic activity than that of defect free samples. This may

be due to hindered electron transport in MoS 2 due to presence of defect.