Hydrophobic and Electronic Properties of the E‐MoS₂ Nanosheets Induced by FAS for the CO₂ Electroreduction to Syngas with a Wide Range of CO/H₂ Ratios

Abstract

Abstract The electrochemical CO 2 reduction reaction (CO 2 RR) to produce CO and H 2 (syngas) is a promising method for clean energy, but challenges remain, such as controlling the CO/H 2 ratios required for the syngas yield. Herein, hydrophobic exfoliated MoS 2 (H‐E‐MoS 2 ) nanosheets are fabricated from bulk MoS 2 by a cost‐effective ball‐milling method, followed by decoration with fluorosilane (FAS). H‐E‐MoS 2 is a cost‐effective electrocatalyst capable of directly reducing CO 2 and H 2 O for tuneable syngas production with a wide range of CO/H 2 ratios (from 1:2 to 4:1). In addition, H‐E‐MoS 2 shows a high current density, 61 mA cm −2 at −1.1 V, and the highest CO FE of 81.2% at −0.9 V, which are higher than those of unmodified MoS 2 . According to density functional theory calculations, FAS decoration on the surface of MoS 2 electrode can change the electronic properties of the edge Mo atom, which facilitates the rate‐limiting CO‐desorption step, thus promoting CO 2 RR. Moreover, the hydrophobic surface of H‐E‐MoS 2 depressed the H 2 evolution reaction and created abundant three‐phase contact points that provided sufficient CO 2 . The hydrophobization of the electrode may provide an effective strategy for easily tuning the CO/H 2 ratio of syngas in a large range for the direct electroreduction CO 2 to syngas with an optimized CO/H 2 ratio.