Sulfonic acid/sulfur trioxide (SO3H/SO3) functionalized two-dimensional MoS2 nanosheets for high-performance photocatalysis of organic pollutants

Abstract

We report the enhanced photocatalytic activity of sulfonic acid/sulfur trioxide (SO₃H/SO₃) functionalized two-dimensional (2D)-MoS₂ (SO₃H/SO₃-MoS₂) nanosheets synthesized using a one-pot hydrothermal method. The functionalization causes the expansion of MoS₂ interlayers and widening of the bandgap while keeping the basal plane intact, thereby improving the catalytically active surface sites and low charge recombination rates. The photocatalytic activity of SO₃H/SO₃-MoS₂ was evaluated by calculating the rate constant of ∼0.06728 min⁻¹ while the dye degradation time was obtained as ∼50 min (10 ppm), which was faster compared to those of the bulk MoS₂ and pristine 2D-MoS₂ nanosheets under identical conditions. The enhancement in the photocatalytic rate-kinetics of SO₃H/SO₃-MoS₂ was accomplished owing to the widening of the bandgap, the expanded 2D-MoS₂ interlayers, the improved surface adsorption/desorption, and the enhanced redox properties as a result of the faster charge-transfer.