Two-dimensional transition metal dichalcogenides beyond MoS2 for the catalytic reduction of nitroarenes: MoSe2 exhibits enhanced performance

Two-dimensional (2D) MoSe2 nanosheets were investigated as a catalyst for nitroarene reduction in the context of water treatment and demonstrated to exhibit a higher activity than their more studied MoS2 counterpart. Density functional theory (DFT) calculations disclosed a feasible nitroarene reduction pathway on 2D MoSe2, which involved passivation of the active site by oxygen from the nitro group and its reactivation by a reducing hydride. DFT analysis also provided an explanation for the isomer selectivity displayed by the 2D MoSe2 catalyst (towards, e.g., 2-, 3-and 4-nitroaniline). To facilitate their practical implementation, the bare MoSe2 nanosheets were coated with colloidal stabilizers, and were also immobilized on polymer foam, where they could be re-used for several consecutive catalytic cycles with no significant loss of activity. Overall, the present results open the prospect of 2D transition metal dichalcogenides beyond MoS2 as competitive nanocatalysts for the reduction of nitroarenes and other organic compounds.