Nano Ag‐Decorated MoS 2 Nanosheets from 1T to 2H Phase Conversion for Photocatalytically Reducing CO 2 to Methanol

Exfoliated MoS 2 with a 2H phase has unique semiconductor properties and is used for the photocatalytic reduction of CO 2 herein. Flower‐like MoS 2 nanosheets are synthesized by the hydrothermal method and are used to fabricate an enlarged lamellar structure with a 1T phase of MoS 2 in the presence of lithium ions under sonication; the 1T‐to‐2H phase conversion of MoS 2 is successfully realized in o ‐dichlorobenzene solution. To improve the photocatalytic performance, Ag nanoparticles are combined with the as‐prepared 2H‐MoS 2 to form the Schottky knot. The obtained Ag/2H‐MoS 2 composites are characterized and evaluated for their compositions, morphologies, microstructures, and photocatalytic activities in the reduction of CO 2 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 CO 2 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 MoS 2 . Finally, a reasonable photocatalytic reaction mechanism is proposed.