Efficacious CO₂ Adsorption and Activation on Ag Nanoparticles/CuO Mesoporous Nanosheets Heterostructure for CO₂ Electroreduction to CO

Abstract

It is an ongoing pursuit for researchers to precisely control the catalyst’s surface for high-performance CO2 electrochemical reduction (CO2ER). In this work, CuO mesoporous nanosheets (CuO MNSs) with rough edges decorated by small Ag nanoparticles (Ag NPs) with a tunable amount of Ag were synthesized on a Cu foil at normal atmospheric temperature through two-step solution-phase reactions for CO2ER to CO. In this special Ag NPs/CuO MNSs heterostructure, the mesoporous CuO NSs with rough edges favored gas infiltration, while decorated Ag NPs expanded the active sites for CO2 molecule adsorption. Ag NPs endowed Ag NPs/CuO MNSs with good electrical conductivity and promoted the adsorbed CO2 molecules to obtain electrons from the catalyst. Especially, the Ag–CuO interface stabilized the *COOH intermediate with strong bonding, which is important in boosting CO2ER to CO. The optimal Ag1.01%/CuO can catalyze CO2ER to CO with a Faradaic efficiency of 91.2% and a partial current density of 10.5 mA cm–2 at −0.7 V. Moreover, it exhibited prominent catalytic stability, retaining 97.8% of the initial current density and 97.6% of the original Faradaic efficiency for CO after 12 h of testing at −0.7 V. Notably, the Faradaic efficiency of CO on Ag1.01%/CuO can retain over 80% in the potential area from −0.6 to −0.9 V, embodying its high selectivity for CO. This work develops precious metal/metal oxide heterostructures with a low precious metal loading for efficacious CO2ER to CO and beyond.

Sn Dopants with Synergistic Oxygen Vacancies Boost CO2 Electroreduction on CuO Nanosheets to CO at Low Overpotential

“…In Figure S6, there were three peaks at 269, 320, and 605 cm −1 corresponding to the A g , B g1 , and B g2 modes of the CuO crystal on CuO nanosheets, respectively. 28 Obviously, the three peaks shifted to higher wavenumbers for V o -CuO(Sn), and a new weak peak that appeared at 485 cm −1 could be assigned to the E g mode of SnO 2 . 29 Therefore, by combining the XPS, ICP-OES, and Raman results, it could be concluded that Sn atoms were successfully introduced into the CuO lattice by partially replacing the positions of the Cu atoms.…”

“…To further confirm the successful doping of Sn elements, Raman spectra of CuO and V o -CuO­(Sn) samples were performed. In Figure S6, there were three peaks at 269, 320, and 605 cm –1 corresponding to the A g , B g1 , and B g2 modes of the CuO crystal on CuO nanosheets, respectively . Obviously, the three peaks shifted to higher wavenumbers for V o -CuO­(Sn), and a new weak peak that appeared at 485 cm –1 could be assigned to the E g mode of SnO 2 .…”

Electrochemical CO2 Reduction by Chalcogenide-Derived Cu Electrocatalysts: A Review

“…The excellent ECR activity is attributed to the more active sites and good mass transfer of nanosized catalyst(Figure 2a-c) . Zhang et al [41] presented an Ag nanoparticles decorated CuO mesoporous nanosheets with rough edges growing on the surface of copper foil (Ag NPs/CuO MNSs). The FE for CO is 91.2 % with a partial current density of 10.5 mA cm -2 at an applied potential of -0.7 V (vs.RHE).…”

Design and Synthesis of Ag‐based Catalysts for Electrochemical CO2 Reduction: Advances and Perspectives

“…Zhang and co‐workers used two‐step solution‐phase reactions to synthesize Ag 1.01% /CuO. A tunable amount of Ag NPs were decorated on the mesoporous CuO nanosheets (CuO MNSs) with rough edges [71] . The mesoporous CuO NSs favor gas infiltration, and Ag NPs expand the active sites for CO 2 adsorption and endow good electrical conductivity for the special heterostructure.…”

“…A tunable amount of Ag NPs were decorated on the mesoporous CuO nanosheets (CuO MNSs) with rough edges. [71] The mesoporous CuO NSs favor gas infiltration, and Ag NPs expand the active sites for CO 2 adsorption and endow good electrical conductivity for the special heterostructure. Therefore, the optimal Ag 1.01% / CuO can catalyze CO 2 to CO with a FE CO of 91.2% and CO partial current density of 10.5 mA cm À 2 at À 0.7 V. Moreover, it can retain 97.8% of the initial current density and 97.6% of the original FE CO for CO after 12 h testing at À 0.7 V, demonstrating a prominent catalytic stability.…”