Engineering of Single Atomic Cu-N₃ Active Sites for Efficient Singlet Oxygen Production in Photocatalysis

Abstract

Photocatalytic generation of singlet oxygen (1O2) is an attractive strategy to convert organic chemicals to high value-added products. However, the scarcity of suitable active sites in photocatalysts commonly leads to the poor adsorption and activation of oxygen molecules from a triplet state to a singlet state. Here, we report single atomic Cu-N3 sites on tubular g-C3N4 for the production of singlet oxygen. X-ray absorption fine spectroscopy, in combination with high-resolution electron microscopy techniques, determines the existence of atomically dispersed Cu sites with Cu-N3 coordination mode. The combined analysis of electron spin resonance and time-resolved optical spectra confirmed that a single atomic Cu-N3 structure facilitates a high concentration of 1O2 generation due to charge transport, electron–hole interaction, and exciton effect. Benefiting from the merits, a single atomic photocatalyst yields nearly 100% conversion and selectivity from thioanisole to sulfoxide within 2.5 h under visible light irradiation. This work deeply reveals the design and construction of catalysts with specific active sites, which are helpful to improve the activation efficiency of oxygen.

Single and dual metal atom catalysts for enhanced singlet oxygen generation and oxygen reduction reaction

“…2 Previous studies have devoted tremendous efforts to SACs for various electrochemical reactions. [3][4][5][6][7][8][9][10] However, the application of SACs and DACs for photochemical reactions such as 1 O 2 sensitization, the CO 2 reduction reaction (CO 2 RR), the oxygen reduction reaction (ORR), the hydrogen evolution reaction (HER), the N 2 reduction reaction (NRR), and photoinduced electron/energy transfer reversible addition-fragmentation chain transfer (PET-RAFT) polymerization has rarely been reported. 11,12 More specically, 1 O 2 sensitization can be used for organic synthesis, wastewater treatment, and photodynamic therapy (PDT).…”

Photocatalytic Ag Nanoparticle Growth Induced Oxygen Vacancy Formation on Few-Layered BiOBr Nanosheets and Enhancements of ·O2– Generation Toward Tetracycline Photodegradation

“…The relative contents of the ROSs generated by the photoexcitation are strongly dependent upon the properties of the photocatalysts . As reported previously, oxygen vacancy-rich perovskite La 0.8 Sr 0.2 CoO 3 is dominated with the production of oxygen ions, while the single atomic Cu-N 3 photocatalyst is favorable for the generation of 1 O 2 . The generation of the ROSs can also be regulated by modification of the photocatalysts.…”

“…7 As reported previously, oxygen vacancyrich perovskite La 0.8 Sr 0.2 CoO 3 is dominated with the production of oxygen ions, 8 while the single atomic Cu-N 3 photocatalyst is favorable for the generation of 1 O 2 . 9 The generation of the ROSs can also be regulated by modification of the photocatalysts. For example, the deposition of Bi on the (001) facet of Bi 2 MoO 6 can effectively intensify molecular oxygen activation, promoting the generation of more ROSs to achieve efficient photocatalytic activity for sodium pentachlorophenate removal.…”

Precise Modulation of the Coordination Environment of Single Cu Site Catalysts to Regulate the Peroxymonosulfate Activation Pathway for Water Remediation

“…All the above results confirmed the atomically dispersed Cu sites on the N-C substrate. In addition, as displayed in Figure S2, N 1s spectra of Cu-N x SACs samples could be deconvoluted into five peaks, which can be ascribed to pyridinic N, pyrrolic N, Cu-N x , graphitic N, and oxidized N, respectively . The pyridinic N contents of Cu-N 4 , Cu-N 3 , and Cu-N 2 were about 40.70, 36.04, and 27.39%, respectively.…”