Selective conversion of CO₂ to CH₄ enhanced by WO₃/In₂O₃ S-scheme heterojunction photocatalysts with efficient CO₂ activation

Abstract

Solar-powered CO2 reduction is a promising approach for mitigating the energy crisis and environmental issues. However, its efficiency is hindered by challenges including difficult CO2 activation, rapid charge recombination, and...

Boosting Artificial Photosynthesis: CO2 Chemisorption and S-Scheme Charge Separation via Anchoring Inorganic QDs on COFs

“…The presence of absorption peaks of monodentate carbonate (m-CO 3 2– , 1507, 1484, and 1310 cm –1 ), bidentate carbonate (b-CO 3 2– , 1587 cm –1 ), bicarbonate (HCO 3 – , 1422 and 1354 cm –1 ), and CO 2 – (1612 and 1244 cm –1 ) suggests the chemisorption of CO 2 on the COF/QDs heterojunction (Figure S20). − Under light irradiation, new adsorption signals corresponding to *COOH (1705 cm –1 ), *CO (2078 cm –1 ), *CHO (1008 cm –1 ), *CH 2 O (967 cm –1 ), and *CH 3 O (1103 and 1187 cm –1 ) are observed, which are critical intermediates in the formation of CO and CH 4 . − During CO 2 photoreduction, the *CO*H intermediate on the catalyst can undergo three processes: the desorption of CO (Pathway I), the release of H from the interface (Pathway II), and continuous protonation to form the *CHO species and generate CH 4 (Pathway III). DFT calculations reveal that the Δ G values for the three pathways are −0.21, – 0.22, and −0.91 eV, respectively (Figure d), providing a reasonable explanation for the production of CO and CH 4 over the COF/QDs heterojunctions.…”

Synergism of the Plasmonic Effect and Schottky Junction to Effectively Facilitate Photocatalytic CO2 Reduction of Bi4O5I2@Cu

“…In addition, as shown in Figure 5d, there are no obviously desorption peaks at 80−200 °C for Bi 4 O 5 I 2 @Cu-0.5 and Bi 4 O 5 I 2 MFs, indicating the weak physical adsorption of CO 2 in the two samples. 55 In the temperature range of 400− 800 °C, both present the evident desorption peak, evincing the strong chemisorption of CO 2 in the two samples. 55 Additionally, from Figure 5d, we can detect the obviously larger peak area of Bi 4 O 5 I 2 @Cu-0.5 relative to that of Bi 4 O 5 I 2 MFs at the desorption temperature ranging from 310 to 550 °C, further ascertaining the improved CO 2 adsorption capacity due to the lower adsorption energy (E ads ) of CO 2 adsorbed on the I atom of Bi 4 O 5 I 2 after the introduction of Cu NPs (Figure S12).…”

“…55 In the temperature range of 400− 800 °C, both present the evident desorption peak, evincing the strong chemisorption of CO 2 in the two samples. 55 Additionally, from Figure 5d, we can detect the obviously larger peak area of Bi 4 O 5 I 2 @Cu-0.5 relative to that of Bi 4 O 5 I 2 MFs at the desorption temperature ranging from 310 to 550 °C, further ascertaining the improved CO 2 adsorption capacity due to the lower adsorption energy (E ads ) of CO 2 adsorbed on the I atom of Bi 4 O 5 I 2 after the introduction of Cu NPs (Figure S12). This is conducive to the acceleration of the photocatalytic CO 2 reaction.…”

Construction of 2D S‐Scheme Heterojunction Photocatalyst

“…In another work, In 2 O 3 nanoparticles were deposited on WO 3 nanosheets to construct a WO 3 /In 2 O 3 S‐scheme heterojunction. [ 54 ] In 2 O 3 was a visible‐light‐responsive photocatalyst with CB and VB positions higher than those of WO 3 . Experimental characterizations and DFT calculation verified that the loading of In 2 O 3 nanoparticles not only enhanced the charge separation and reduction ability of WO 3 but also helped to adsorb and activate CO 2 molecules.…”