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An innovative strategy for synthesizing novel dual-reaction-center (DRC) catalysts from chicken manure (CM) biochar to purify wastewater that contained emerging contaminants (ECs) is proposed to synchronously address the release of ECs and improper disposal of livestock manure. A series of characterization techniques reveal the formation of a special C-O-Ca bond bridge (cation-π) structure on resourcelized CM nanosheets (RCM NSs). RCM NSs exhibit distinct selectivity and anti-interference capability for various ECs removal in complex matrices, and the water purification system remains stable after 1735 hours (equivalent to 3470 cycles) of operation. Density Functional Tomography (DFT) calculations reveal that trace of peroxymonosulfate as an inducer initiates the continuous donation of electrons from electron-rich ECs and the C-O-Ca bond bridges provide a favorable pathway for electron transfer, which facilitates the electron capture effect of dissolved oxygen in the system. This study provides a novel strategy to convert livestock manure into DRC-catalysts for developing energy-saving and high-efficiency environmental remediation technologies. Highlights: • The chicken manure biochar was converted into a water purification catalyst through a graphitization process. • Resourcelized catalyst RCM NSs had superior removal capability for various ECs triggering by trace of PMS. • RCM NSs could quickly eliminate ECs and simultaneously drive NOM removal, even with NOM interference. • The key role of dissolved oxygen for water purification was illustrated in RCM NSs system. [ABSTRACT FROM AUTHOR]

For the sustainable reutilization of poultry feces (PF) to reduce environmental pollution, we present a novel approach for converting PF into a highly effective catalyst, consisting of trace copper (Cu) and sulfur (S) linked with ordered graphitized carbon (CS/CPF) for wastewater purification. Raman and EPR results verified that the disorderly organic matters in PF are transformed into orderly graphene structures that complexed with Cu to form large numbers of electron-poor/rich microregions on CS/CPF surface. The electrons from electron-rich organic pollutants can be directly captured by dissolved oxygen (DO) to produce abundant reactive oxygen species due to the enhanced electron polarization via the construction of Cu–S–C bond bridge on CS/CPF surface, which greatly enhance the removal efficiency of pollutants. CS/CPF achieves 100% removal for 2,4-dichlorophenoxyacetic acid (2,4-D) in just 10 min after adding trace peroxymonosulfate (PMS), keeping efficient catalytic activity after continuous reactions for 240 h. This strategy offers a practical and sustainable solution for the efficient resource recovery of poultry feces. [Display omitted] • PF was turned into a water purification catalyst by original resourcing technology. • Surface electron-rich/poor microregions were induced by trace Cu and S. • Refractory pollutants were quickly removed in just 10 min triggered by trace PMS. • Electrons of pollutant were utilized during a new interface reaction process. [ABSTRACT FROM AUTHOR]

[Display omitted] Herein, a novel metal-free catalyst consisting of multiporous oxygen-rich carbon–nitrogen graphene-like nanosheets (O LAA -CN NSs) is first developed through a staged temperature-programmed calcination of l -ascorbic acid (LAA)-modified dicyandiamide precursor. It is found that the oxygen species from l -ascorbic acid (O LAA) are introduced into the graphene-like basic matrix and replace partial N atoms to form the C O C-R structure, leading to the non-uniform distribution of electrons on the catalyst surface, and the formation of electron-rich centers around the C O C microareas according to a series of characterization techniques. As a result, O LAA -CN NSs exhibits excellent performance for refractory pollutant removal in the presence of peroxymonosulfate (PMS) and dissolved oxygen. Some pollutants with complex structures are even completely degraded within only 1 min. The interface reaction mechanism is further revealed that PMS mainly acts as an active inducer to drive the electron donation of pollutants over O LAA -CN NSs. These electrons are finally utilized by dissolved oxygen to generate reactive oxygen species (ROS) through the interface process. This reaction system results in pollutants that can either be cleaved directly by surface oxidation process or degraded by the attack of the generated ROS, such as singlet oxygen (1O 2) and superoxide radicals (O 2 •−), through oxygen activation, which significantly reduces the resource and energy consumption in advanced wastewater treatment by harnessing the energy of pollutants and dissolved oxygen in the water. [ABSTRACT FROM AUTHOR]

[Display omitted] • Single-atom Co-N 4 sites were constructed in Co-doped g-C 3 N 4. • The k obs of CBZ degradation reached 0.355 min−1, while PMS decomposition was mild. • 1O 2 and Co(IV) = O both played an important role in the degradation of CBZ. • PMS → OH*→Co(IV) = O → OO*→1O 2 was proposed as the optimal evolution path of PMS. • The release of 1O 2 was the rate-determining step in the path of Co(IV) = O to 1O 2. Tailoring the interfacial reaction pathway and low consumption strategy for the high efficiency Fenton-like processes is environmentally desirable but still challenging. Herein, single Co atom-doped g-C 3 N 4 was prepared for peroxymonosulfate (PMS) activation to reveal the interfacial reaction of high-valent cobalt-oxo species [Co(IV) = O] to singlet oxygen (1O 2) and construct an energy efficient Fenton-like system. Experimental results showed that the system could achieve 99.6% carbamazepine removal with k obs of 0.355 min−1, while the decomposition of PMS was mild (0.0988 and 0.00917 min−1 in 0–2 and 2–30 min, respectively). Mechanistic studies revealed the reaction of Co(IV) = O to 1O 2 , which moderated the reduction of Co sites, thus slowing the decomposition rate of PMS. But the synergistic effect of 1O 2 and Co(IV) = O maintained the high activity of the system. Combined with first-principles calculations, the optimal evolution path of PMS was PMS → OH*→Co(IV) = O → OO*→1O 2 , accompanied by the Co(II)/Co(III)/Co(IV) redox cycle. The work proposed a new interfacial reaction in term of Co(IV) = O triggered 1O 2 generation, resulting in the construction of an energy-efficient Fenton-like system and provided a novel idea for the development of efficient and low consumption water purification technology. [ABSTRACT FROM AUTHOR]

[Display omitted] • Zero-added conversion of chicken manure into water treatment catalyst (RCM) is realized. • Electron-poor/rich microregions are successfully constructed on RCM. • Pollutant degradation processes can be driven by a little bit of peroxymonosulfate. • RCM has excellent performance on actual wastewater treatment. • Water treatment with low consumption is achieved by utilization of pollutants. Fecal pollution in rural areas and water pollution caused by emerging contaminants (ECs) are two international environmental problems. Here, we propose a new strategy to address the two problems simultaneously through the resource utilization and harmless transformation of poultry manure as a kind of water purification catalyst with zero addition. The ordered bonding of intrinsic metal-organic species is realized in the resourcelized procedure by a one-stage calcination-annealing method, which results in the formation of electron-rich/poor microregions. With the triggering of a small amount of peroxymonosulfate (PMS), the energy/electrons of ECs are utilized by the dissolved oxygen in water driven by the electron-rich/poor microregions on the catalyst surface. As a result, the system exhibits excellent performance in removing various ECs. The degradation rate can even be maintained above 94.3 % after 10,000 cycles. This work indicates a sustainable approach to the effective utilization and treatment of rural waste and pollutants. [ABSTRACT FROM AUTHOR]

• N-doped porous carbon was prepared via transformation from graphitic carbon nitride. • N-doped porous carbon (NC 1.0) possesses ultrahigh N content up to 33.75 at%. • NC 1.0 exhibits excellent reactivity and stability for peroxymonosulfate activation. • DFT calculations reveal PMS activation involving PMS reduction and oxidation. • Singlet oxygen (1O 2) is the main reactive oxygen species in the NC 1.0 /PMS system. Nitrogen-doped carbon materials are proposed as promising metal-free catalysts for persulfate-mediated catalytic oxidation process, yet the nitrogen content in the final carbon products is typically low. Moreover, controversies remain in the unambiguous identification of active sites in nitrogen-doped carbons for persulfate activation. Here we report the facile synthesis of nitrogen-doped carbon material via one-step pyrolysis of urea and D-mannitol, which simultaneously combine ultrahigh nitrogen content (up to 33.75 at%) with apparent porous structure via transformation from graphitic carbon nitride. With this strategy, the highly nitrogen-doped porous carbon (NC 1.0) exhibits excellent catalytic activity toward peroxymonosulfate (PMS) activation for oxidation of organic pollutants. Both experiments and density functional theory (DFT) calculations, for the first time, revealed that the electron-rich graphitic N and electron-deficient carbon atom adjacent to graphitic N in NC 1.0 served as active sites for PMS reduction and oxidation toward the generation of hydroxyl radical (OH) and singlet oxygen (1O 2), respectively, in which PMS oxidation was the main reaction in the course of PMS activation rendering 1O 2 the dominant reactive oxygen species (ROS) in the NC 1.0 /PMS system. More importantly, NC 1.0 presents robust stability in PMS activation, superior to most reported nitrogen-doped carbon-based catalysts, offering great promise for practical environmental remediation. [ABSTRACT FROM AUTHOR]