Dual active sites fabricated through atomic layer deposition of TiO on MoS nanosheet arrays for highly efficient electroreduction of CO to ethanol

Electrochemical reduction of CO 2 to ethanol through renewable electricity is highly desirable but still challenging. Here, we demonstrated that TiO 2 /MoS 2 nanosheet arrays synthesized through atomic layer deposition (ALD) of TiO 2 on the surfaces of MoS 2 nanosheet arrays enabled the electrochemical CO 2 reduction reaction (CO 2 RR) toward ethanol. As a result, 50% faradaic efficiency (FE) for ethanol was achieved over the obtained electrocatalyst at only −0.60 V versus the reversible hydrogen electrode (RHE) in CO 2 -saturated 0.5 M KHCO 3 aqueous solution, which ranks as the best electrocatalysts for the CO 2 RR to ethanol. The experimental results and theoretical calculations showed that Mo and Ti dual active sites formed on the interfaces of TiO 2 and MoS 2 could adjust CO binding energy and promote the CO-CO coupling reaction and its subsequent transformation. A new regulatory mechanism of the CO coupling reaction and the possible reaction path were proposed based on experimental results and density functional theory (DFT) calculations. Ultrathin TiO 2 /MoS 2 nanosheet arrays containing dual active sites could achieve efficient CO 2 reduction reaction toward ethanol. A new regulatory mechanism of the CO coupling reaction was proposed based on experimental results and DFT calculations.