Electronic Structure Manipulation via Site-Selective Atomically Dispersed Ni for Efficient Photocatalytic CO₂ Reduction

Abstract

Single-atom catalysts (SACs) have recently emerged as promising photocatalysts for CO 2 reduction; however, understanding their interplay between the local electronic structure and the overall performance at an atomic level still remains elusive. Here, we construct two Ni-SACs at different sites of WO 2.72 nanowires, i.e., bulk doping of single Ni atoms in WO 2.72 (B-Ni 1 /WO 2.72 ) and surface anchoring of single Ni atoms on WO 2.72 (S-Ni 1 /WO 2.72 ), to unravel the electronic structure manipulation for boosting CO 2 photoreduction. Impressively, B-Ni 1 /WO 2.72 displays superior photocatalytic CO 2 reduction performance to S-Ni 1 /WO 2.72 , reaching a CO yield of 80.5 mmol g −1 h −1 with a selectivity of 98.7%. Experimental results and computational calculations reveal that compared to S-Ni 1 /WO 2.72 , B-Ni 1 /WO 2.72 is endowed with improved charge transfer and a more upshifted d-band center, thereby leading to CO production with concurrent high activity and selectivity. This work provides deeper insights into the exploration of efficient SACs for artificial photosynthesis to targeted products by optimization of their site-related electronic structures.

Single Cobalt Atoms Induced Molecular O2 Activation for Enhanced Photocatalytic Biomass Upgrading on ZnIn2S4 Nanosheets

“…As presented in Figure S22a, the fluorescence intensity of Co 1 /ZIS is significantly weaker than that of pristine ZIS, which means the effective charge separation and transfer in Co 1 /ZIS. Also, from the TRPL spectra (Figure S22b) and fitted values (Table S5) of pristine ZIS and Co 1 /ZIS catalysts, Co 1 /ZIS displays a shorter average exciton lifetime (3.95 ns) than ZIS (4.89 ns), indicating that the introduction of single-atom Co species can effectively improve the separation and transfer of photoinduced carriers . Furthermore, compared to pristine ZIS, significantly improved transient photocurrent response (Figure S22c) and lower charge transfer resistance in electrochemical impedance spectra (Figure S22d) were observed over the Co 1 /ZIS catalyst, confirming the beneficial role of Co single atoms in boosting photogenerated charge transfer.…”

Cayanamide Group Functionalized Crystalline Carbon Nitride Aerogel for Efficient CO2 Photoreduction

“…Furthermore, careful comparison reveals that these two COOH* bands are significantly strengthened on CCN aerogel relative to PCN and CCN, with two additional FTIR bands (1634 and 1435 cm −1 ) attributed to COOH* only observed on CCN aerogel, [ 44,45 ] which implies the favoured accumulation and protonation of CO 2 * for the generation of COOH* on CCN aerogel. On CCN and CCN aerogel, one could further note a distinct band at ≈2070 cm −1 , attributed to the surface‐adsorbed CO* intermediate (COOH* + H + + e − → CO* +H 2 O), [ 46 ] with intensity gradually increased with the prolonged irradiation time. However, this peak could be hardly observed on PCN.…”

“…By contrast, the free energy difference for the generation of COOH* and CO* intermediates are much lower for CCN aerogel than for PCN (Figure 5e). Especially, for the formation of COOH* intermediate regarded as the rate‐determining step for CO 2 ─to─CO reduction reaction, [ 46,48 ] a free energy difference of 1.82 eV as high is required by PCN, which is greatly reduced to 1.50 eV for CCN aerogel. This phenomenon confirms that the ─CN groups introduced into CCN aerogels are conducive to the hydrogenation of surface‐adsorbed CO 2 * into COOH*, due to the thermodynamically stable bridging structure of COOH* anchoring at the positive C (0.460 e) and negative N (−0.730 e) atoms in ─CN groups (Figure S23, Supporting Information).…”

High-performance artificial leaf: from electrocatalyst design to solar-to-chemical conversion

“…29,30 In order to mitigate the increasing greenhouse effect and achieve the global zero-carbon goal, the development of efficient ways to reduce CO 2 to high value-added chemicals is important for both scientific research and practical applications. 31–35…”