Construction of unique two-dimensional MoS-TiO hybrid nanojunctions: MoS as a promising cost-effective cocatalyst toward improved photocatalytic reduction of CO to methanol.

Two-dimensional MoS nanosheets were in situ grown on TiO nanosheets to form two-dimensional (2D) hybrid nanojunctions, with which MoS nanosheets compactly contact with TiO to increase the interfacial area. MoS was identified as a promising cost-effective substitute for noble metal cocatalysts such as Pt, Au, and Ag, and shows superior activity and selectivity for reducing CO to CHOH in aqueous solution to these metal cocatalysts under UV-vis light irradiation. The photo-luminescence (PL) spectra and transient time-resolved PL decay measurements reveal that the fast electron transfer from TiO to MoS can minimize charge recombination losses to improve the conversion efficiency of photoreduction. It reveals that Mo-terminated edges of MoS nanosheets possess the metallic character and a high d-electron density, and the Mo cation sites may benefit the stabilization of CHO intermediates via electrostatic attraction to enhance the CHOH formation from the reduction of CO in aqueous solution.