Accelerating Surface Photoreactions Using MoS2-FeS2 Nanoadsorbents: Photoreduction of Cr(VI) to Cr(III) and Photodegradation of Methylene Blue

Nanocubic MoS2-FeS2, as a photocatalyst, was synthesized with high catalytic active edges and high specific surface areas with the capability of absorbing visible light. The results showed that the photocatalytic efficiency of nanocubic MoS2-FeS2 for adsorption/degradation of methylene blue (MB) as well as the reduction of Cr(VI) was high. The adsorption process was found to follow a kinetic model of a pseudo-second-order kind (Q(e.cal) = 464 mg g(-1)) along with an isotherm described by the Langmuir model with Q(e.cal) = 340 mg g(-1). The photodegradation process was achieved by holes. It was found that the photodegradation rate constant of MB by MoS2-FeS2 (0.203 min(-1)) was about 22 times higher than that of MoS2 (0.0091 min(-1)). The percent apparent quantum yield for photoreduction of Cr(VI) to Cr(III) using MoS2-FeS2 (5.7%) was about 33 times higher than utilizing MoS2 (0.1709%). Therefore, the synergistically prolonged visible-light harvesting as well as the photocarrier diffusion length proved that MoS2-FeS2 nanotubes can effectively be utilized in environmental pollutant's remediation.

Automated summary

Nanocubic MoS2-FeS2, as a photocatalyst, exhibits high efficiency in adsorption and degradation of methylene blue and reduction of Cr(VI) through hole-mediated photodegradation process.