Nano Ag-Decorated MoS2 Nanosheets from 1T to 2H Phase Conversion for Photocatalytically Reducing CO2 to Methanol

Abstract

Exfoliated MoS₂ with a 2H phase has unique semiconductor properties and is used for the photocatalytic reduction of CO₂ herein. Flower-like MoS₂ nanosheets are synthesized by the hydrothermal method and are used to fabricate an enlarged lamellar structure with a 1T phase of MoS₂ in the presence of lithium ions under sonication; the 1T-to-2H phase conversion of MoS₂ is successfully realized in o-dichlorobenzene solution. To improve the photocatalytic performance, Ag nanoparticles are combined with the as-prepared 2H-MoS₂ to form the Schottky knot. The obtained Ag/2H-MoS₂ composites are characterized and evaluated for their compositions, morphologies, microstructures, and photocatalytic activities in the reduction of CO₂ to methanol. Herein, it was found that the electron and hole excited by light on the composites are more effectively separated through deposited nano Ag, and their photocatalytic ability of reducing CO₂ to methanol is promoted simultaneously. The highest yield of methanol up to 365.08 μmol⁻¹ g⁻¹ h⁻¹ appears at 20 wt% Ag on MoS₂. Finally, a reasonable photocatalytic reaction mechanism is proposed.