Isolated single atom cobalt in Bi3O4Br atomic layers to trigger efficient CO2 photoreduction

Abstract

The design of efficient and stable photocatalysts for robust CO 2 reduction without sacrifice reagent or extra photosensitizer is still challenging. Herein, a single-atom catalyst of isolated single atom cobalt incorporated into Bi 3 O 4 Br atomic layers is successfully prepared. The cobalt single atoms in the Bi 3 O 4 Br favors the charge transition, carrier separation, CO 2 adsorption and activation. It can lower the CO 2 activation energy barrier through stabilizing the COOH* intermediates and tune the rate-limiting step from the formation of adsorbed intermediate COOH* to be CO* desorption. Taking advantage of cobalt single atoms and two-dimensional ultrathin Bi 3 O 4 Br atomic layers, the optimized catalyst can perform light-driven CO 2 reduction with a selective CO formation rate of 107.1 µmol g −1 h −1 , roughly 4 and 32 times higher than that of atomic layer Bi 3 O 4 Br and bulk Bi 3 O 4 Br, respectively.

Atomic Thickness Catalysts: Synthesis and Applications

“…Additionally, a method to prepare Co-doped Bi 3 O 4 Br NSs was proposed in a mixture of Bi(NO 3 ) 3 •5H 2 O, PVP, NaBr, and mannitol solution (pH = 11.5, tuned by NaOH) using the solvothermal method. [11] The ultrathin Bi 3 O 4 Br NSs were displayed in Figure 4G and atomic thickness of Bi 3 O 4 Br was clearly determined by the TEM image from Figure 4H (≈1.9 nm). The measured spacing distance of 0.285 nm was corresponded to the Bi 3 O 4 Br with (020) or (200) crystal plane, implying the exposed facet was (002) facet ( Figure 4I).…”

“…[8][9][10] All in all, as for the CO 2 reduction reaction, current catalysts are largely limited to the low catalytic activity and poor production selectivity, which greatly limit the possible practical applications. [11] Recently, intensive attentions have been paid to the ultrathin nanostructures due to their unique surface-related properties, for instance, high electron mobility, [12,13] quantum Hall effect, [14] and unprecedented optoelectronics. [15,16] Particularly, atomic thickness catalysts (ATCs), typically less than 5 nm, have emerged as the hotspots of ultrathin nanostructures ascribed to the promising applications in superior catalytic activities compared to their bulk counterparts.…”

“…[7,[17][18][19] The ATCs including metals (alloys), LDHs, TMDs, TMOs, carbon based materials, are endowed with higher specific surface and density of unsaturated atoms, providing ideal properties with low-cost, highstability and excellent performance for the energy conversion applications. [3,11,18,[20][21][22][23][24] Exciting breakthroughs of various kinds of ATCs with a controllable morphology, domain size, structure, and composition have been made. [18,25] For instance, Guo's group successfully prepared a free-standing PdMo bimetallene with a thickness of 4-atom, giving a significantly higher atomic utilization >0.5 and a much larger mass activity of oxygen reduction reaction compared with commercial Pt/C and Pd/C, respectively.…”

“…and surface effects. Hence, photogenerated charge carriers could migrate fast from inside of the materials to the surface which were induced by these quantum effects [11,50] In particular, the exposed surface atoms with sufficient dangling bonds could establish the interaction with CO 2 molecules and facilitate the formation of surface defects to enhance the CO 2 activity and selectivity. [137] Benefiting from these merits, atomically thin photocatalysts including WO 3 layers, [138,139] Cu doped TiO 2 NSs, [48] ultrathin ZnAl LDH, [140] single-unit-cell BiVO 4 , [6] one-unit-cell ZnIn 2 S 4 , [141] ZnGa 2 O 4 NSs, [142] Bi 2 WO 6 layers, [143] Bi 2 MoO 6 NSs, [144] and Co doped Bi 3 O 4 Br [11] have been developed for photocatalytic CRR.…”

Strategies for Designing Nanoparticles for Electro‐ and Photocatalytic CO2 Reduction

“…(d) CO evolution rate of Co‐Bi 3 O 4 Br with a different amount of Co. Reprinted and adapted with permission from Ref. . Copyright © 2019, Springer Nature.…”