Search

Emerging single‐atom catalysts (SACs) are promising in water remediation through Fenton‐like reactions. Despite the notable enhancement of catalytic activity through increasing the density of single‐atom active sites, the performance improvement is not solely attributed to the increase in the number of active sites. The variation of catalytic behaviors stemming from the increased atomic density is particularly elusive and deserves an in‐depth study. Herein, single‐atom Fe catalysts (FeSA‐CN) with different distances (dsite) between the adjacent single‐atom Fe sites are constructed by controlling Fe loading. With the decrease in dsite value, remarkably enhanced catalytic activity of FeSA‐CN is realized via the electron transfer regime with peroxymonosulfate (PMS) activation. The decrease in dsite value promotes electronic communication and further alters the electronic structure in favor of PMS activation. Moreover, the two adjacent single‐atom Fe sites collectively adsorb PMS and achieve single‐site desorption of the PMS decomposition products, maintaining continuous PMS activation and contaminant removal. Moreover, the FeSA‐CN/PMS system exhibits excellent anti‐interference performance for various aquatic systems and good durability in continuous‐flow experiments, indicating its great potential for water treatment applications. This study provides an in‐depth understanding of the distance effect of single‐atom active sites on water remediation by designing densely populated SACs. [ABSTRACT FROM AUTHOR]

• The Fenton-like Cu-PAN 3 catalysts is first synthesized by co-precipitation and carbon thermal reduction method. • Dual reaction centers are constructed around graphene-like carbon and Cu species. • The pollutants as electron donors inhibit the ineffective decomposition of H 2 O 2 at the electron-poor centers. • The pollutant removal mainly relies on the surface cleavage at the electron-poor centers. High energy consumption has seriously hindered the development of Fenton-like reactions for the removal of refractory organic pollutants in water. To solve this problem, we designed a novel Fenton-like catalyst (Cu-PAN 3) by coprecipitation and carbon thermal reduction. The catalyst exhibits excellent Fenton-like catalytic activity and stability for the degradation of various pollutants with low H 2 O 2 consumption. The experimental results indicate that the dual reaction centers (DRCs) are composed of Cu-N-C and Cu-O-C bridges between copper and graphene-like carbon, which form electron-poor/rich centers on the catalyst surface. H 2 O 2 is mainly reduced at electron-rich Cu centers to free radicals for pollutant degradation. Meanwhile, pollutants can be oxidized by donating electrons to the electron-poor C centers of the catalyst, which inhibits the ineffective decomposition of H 2 O 2 at the electron-poor centers. This therefore significantly reduces the consumption of H 2 O 2 and reduces energy consumption. [Display omitted] [ABSTRACT FROM AUTHOR]

Solid solution of BiOBr and BHO (BiO(OH) 0.06 Br 0.94 ) with abundant oxygen vacancies was supported on Ag/AgBr using precipitation and deposition–precipitation methods. The photocatalyst showed high and stable photocatalytic activity for the degradation of chlorophenols and azodyes in water under visible to NIR light irradiation without any release of Ag + , which came from visible-excited AgBr and the SPR of Ag NPs in the visible and NIR region. The different interfacial charge-transfer processes were verified on the basis of cyclic voltammetry analyses and all experimental information. The conduction band (CB) electrons of photoexcited AgBr reacted with the adsorbed oxygen forming O 2 •− , while the valence band (VB) holes of AgBr were transported the VB of BiO(OH) 0.06 Br 0.94 to oxidize organic pollutants or H 2 O to • OH. The plasmon-induced electrons from Ag NPs transferred to the CB of AgBr reacting with the adsorbed oxygen to O 2 •− , while the electrons trapped on the oxygen vacancies of BiO(OH) 0.06 Br 0.94 transferred to Ag NPs recombining with the plasmon-induced holes, inhibiting the release of Ag + , and the resulted VB holes of BiO(OH) 0.06 Br 0.94 oxidized organic compound. These interfacial charge transfers evidenced the high photoactivity and photostability of BiO(OH) 0.06 Br 0.94 /Ag/AgBr. [ABSTRACT FROM AUTHOR]