Vacancy-defect modulated pathway of photoreduction of CO2 on single atomically thin AgInP2S6 sheets into olefiant gas

Abstract

Artificial photosynthesis, light-driving CO2 conversion into hydrocarbon fuels, is a promising strategy to synchronously overcome global warming and energy-supply issues. The quaternary AgInP2S6 atomic layer with the thickness of ~ 0.70 nm were successfully synthesized through facile ultrasonic exfoliation of the corresponding bulk crystal. The sulfur defect engineering on this atomic layer through a H2O2 etching treatment can excitingly change the CO2 photoreduction reaction pathway to steer dominant generation of ethene with the yield-based selectivity reaching ~73% and the electron-based selectivity as high as ~89%. Both DFT calculation and in-situ FTIR spectra demonstrate that as the introduction of S vacancies in AgInP2S6 causes the charge accumulation on the Ag atoms near the S vacancies, the exposed Ag sites can thus effectively capture the forming *CO molecules. It makes the catalyst surface enrich with key reaction intermediates to lower the C-C binding coupling barrier, which facilitates the production of ethene.

Tuning Metal-Free Hierarchical Boron Nitride-like Catalyst for Enhanced Photocatalytic CO2 Reduction Activity

“…The photocatalytic CO 2 reduction reaction (CO 2 RR) is a promising technology that utilizes solar energy to convert greenhouse gas CO 2 into valuable solar fuels to solve energy shortages and environmental problems. − However, thermodynamic and kinetic constrains of CO 2 RR still limit product yields and selectivity. To develop highly efficient and robust photocatalysts for CO 2 RR, a large number of researchers have made ongoing attempts. − …”

Rapid Hydroxyl Radical Generation on (001)-Facet-Exposed Ultrathin Anatase TiO2 Nanosheets for Enhanced Photocatalytic Lignocellulose-to-H2 Conversion

“…As illustrated in Figure g, the TiO 2 -1 electrode shows a photocurrent of 5.6 μA·cm –2 , which is 1.5 times higher than that of the TiO 2 -2 electrode. In such a smart ultrathin structure of TiO 2 -1, the generated charge carriers can pass quickly to the surface owing to the very short transmission distance, , resulting in an improved photogenerated electron–hole separation efficiency as compared with TiO 2 -2. Furthermore, the larger specific surface area of the TiO 2 -1 sample provides much more abundant active sites for the generation of ● OH, which acts as the key species for the oxidation of lignocelluloses.…”

State-of-the-art advancements of atomically thin two-dimensional photocatalysts for energy conversion

“…Similarly, while the pristine AgInP 2 S 6 atomic layer produces CO as the main product, the sulfur defect engineering on this atomic layer can excitingly change the CO 2 photoreduction reaction pathway of Vs-AgInP 2 S 6 to steer dominant generation of C 2 H 4 with the yield-based selectivity reaching ∼73% and the electron-based selectivity as high as ∼89%. 141 Both DFT calculation (Fig. 8) and in situ FTIR spectra demonstrate that the introduction of S vacancies causes charge accumulation on the Ag atoms near the S vacancies.…”

“…The photocatalytic reduction of CO 2 to valuable hydrocarbons using solar energy is one of the best solutions to solve both the energy shortage and global warming. 141,157,158 The CO 2 molecule is extremely stable, with a dissociation energy >750 kJ mol −1 for the CO bond. Therefore, high energy input is required to break the OCO double bonds during CO 2 photoreduction, which is much more challenging than splitting water into hydrogen.…”