An integrated gradually thinning and dual-ion co-substitution strategy modulated In-O-ultrathin-SnS2 nanosheets to achieve efficient electrochemical reduction of CO2

The unique two-dimensional structure of ultrathin nanomaterials provides an ideal platform for regulating properties at the atomic level. Herein, gradually thinning method combined with dual-ion co-substitution strategy realizes the evolution of micron-sized bulk ZnSn(OH)6-precursor (2 mu m) to functionalized In-O-ultrathinSnS2 nanosheets (3 nm). The In-O-ultrathin-SnS2 achieves formate Faraday efficiency (FEHCOO-) of 88.6% and partial current density (jHCOO-) of 22.7 mA cm-2 at a moderate overpotential of 1.0 V for CO2 electrocatalytic reduction, which demonstrates a remarkable improvement in comparing with that of the unadorned ultrathinSnS2 (FEHCOO- = 17.5%, jHCOO- = 9.4 mA cm-2). Density functional theory calculations demonstrate that the superior activity of In-O-ultrathin-SnS2 is attributed to the synergistic effect among oxidized Sn and the adjacent In sites in reducing the free energy of the key intermediates formation and accelerating the charge transfer rate.

Automated summary

The evolution from micron-sized bulk ZnSn(OH)6-precursor to functionalized In-O-ultrathin-SnS2 nanosheets was achieved by gradually thinning method combined with dual-ion co-substitution strategy, showing remarkable activity and current density in CO2 electrocatalytic reduction.