Surface Oxygen Injection in Tin Disulfide Nanosheets for Efficient CO2 Electroreduction to Formate and Syngas

Abstract

Surface chemistry modification represents a promising strategy to tailor the adsorption and activation of reaction intermediates for enhancing activity. Herein, we designed a surface oxygen-injection strategy to tune the electronic structure of SnS2 nanosheets, which showed effectively enhanced electrocatalytic activity and selectivity of CO2 reduction to formate and syngas (CO and H2). The oxygen-injection SnS2 nanosheets exhibit a remarkable Faradaic efficiency of 91.6% for carbonaceous products with a current density of 24.1 mA cm−2 at −0.9 V vs RHE, including 83.2% for formate production and 16.5% for syngas with the CO/H2 ratio of 1:1. By operando X-ray absorption spectroscopy, we unravel the in situ surface oxygen doping into the matrix during reaction, thereby optimizing the Sn local electronic states. Operando synchrotron radiation infrared spectroscopy along with theoretical calculations further reveals that the surface oxygen doping facilitated the CO2 activation and enhanced the affinity for HCOO* species. This result demonstrates the potential strategy of surface oxygen injection for the rational design of advanced catalysts for CO2 electroreduction.

Bismuth-Nanosheet-Based Catalysts with a Reconstituted Bi0 Atom for Promoting the Electrocatalytic Reduction of CO2 to Formate

“…In situ Raman spectroscopy was performed to study the structural changes of the catalyst surface for the Bi NSs and Bi 2 O 3 precursor under different reduction potentials. As shown in Figure f, except for two obvious peaks at 74 and 99.7 cm –1 for metallic Bi 0 in Bi NSs, a new weak Raman feature assigned to the subcarbonate species (Bi 2 O 2 CO 3 ) for the external vibration mode of BiO appears at 162 cm –1 at the open-circuit potential (OCP), which proves the existence of an extremely thin oxide layer on the surface of Bi NSs . This is because the Bi NSs can easily be oxidized in air to form the Bi 2 O 3 layer on the surface of the nanosheets, and then Bi 3+ in the Bi 2 O 3 layer can react with HCO 3 – to generate Bi 2 O 2 CO 3 in a 0.5 M KHCO 3 electrolyte.…”

“…As shown in Figure 2f, except for two obvious peaks at 74 and 99.7 cm −1 for metallic Bi 0 in Bi NSs, a new weak Raman feature assigned to the subcarbonate species (Bi 2 O 2 CO 3 ) for the external vibration mode of Bi�O appears at 162 cm −1 at the opencircuit potential (OCP), which proves the existence of an extremely thin oxide layer on the surface of Bi NSs. 35 This is because the Bi NSs can easily be oxidized in air to form the Bi 2 O 3 layer on the surface of the nanosheets, and then Bi 3+ in the Bi 2 O 3 layer can react with HCO 3 − to generate Bi 2 O 2 CO 3 in a 0.5 M KHCO 3 electrolyte. As the potential changes from OCP to −0.9 V, the subcarbonate vibrational mode at 162 cm −1 progressively disappears, indicating that the oxide layer can be completely diminished before eCO 2 RR takes place.…”

Quasi-Solid-State Ion-Conducting Arrays Composite Electrolytes with Fast Ion Transport Vertical-Aligned Interfaces for All-Weather Practical Lithium-Metal Batteries

“…To shed more light on the mechanism of Li + transport in CMP/VAMMT, we used 6 Li SSNMR and SRD. 6 Li SSNMR is conducted coupled with 6 Li/ 7 Li isotope-replacement method with 6 Li metal as lithium source in the 6 Li‖Cu cell [40,41]. 6 Li + is stripped from one 6 Li-metal electrode and plated on the other, going through the composite GPE.…”

Operando Converting BiOCl into Bi2O2(CO3)xCly for Efficient Electrocatalytic Reduction of Carbon Dioxide to Formate

“…It is known that electrocatalytic CO 2 RR to HCOOH has normally proceeded via a proton-coupled electron transfer (PCET) step to form * COOH or * OCHO intermediates and followed by another PCET step to generate HCOOH [47]. It is also known that the CO 2 RR pathway depends strongly on the adsorption energy of the intermediates [48]. DFT calculations were therefore carried out to determine the preferential intermediates of the pure tetragonal phased Bi 2 O 2 CO 3 -and Bi 2 O 2 (CO 3 ) x Cl y -catalyzed CO 2 reduction to HCOOH.…”