Oxygen vacancy-mediated d-band center regulation in NiCu0.4Fe1.6O4 via Cu-doping achieves efficient peroxymonosulfate activation for durable water purification

Fast diffusion kinetics improves electron transfer regime selectivity to boost peroxymonosulfate activation

Heteronuclear dual-metal site catalysts (DACs) featuring unique coordination structures enable precise manipulation of metal spin-states, offering great potential for efficient peroxymonosulfate (PMS) activation. In particular, they enable highly efficient generation of high-valent cobalt-oxo (CoIV = O) species. However, the identification and mechanism functions of DACs with axially coordinated diatomic structures remain elusive. Herein, we show a DAC featuring axial Co-O-Cu (CoN4-O-CuN4) pairs embedded in carbon nitride (CoCu-CN). This unique configuration significantly stabilizes the medium-spin state of Co, thereby enhancing PMS activation for efficient CoIV = O generation. Combined experimental and theoretical analyses reveal that superexchange-mediated electron transfer from Co to Cu occurs via Co 3d (dxz/dyz) and O p (px/py) orbitals. This strong Co-O hybridization upshifts the d-band center to -0.41 eV, facilitating PMS adsorption. Furthermore, the orbital polarization optimization of the d orbitals in Co and Cu promotes the simultaneous cleavage of both O-O and O-H bonds for PMS, enabling direct CoIV = O formation. Consequently, this catalyst design achieves high degradation performance, including a sulfisoxazole degradation rate of 1.98 min-1 (5.8 times and 19.8 times higher than Co-CN and Cu-CN). This work establishes a new paradigm for designing PMS activation catalysts that concurrently exhibit spin activity and persistent stability.

Insights into atomic arrangement in CuMnO2 with tailored exposed crystal facets for effectively micropollutant oxidation via peroxymonosulfate activation

Developing highly efficient photocatalysts for purifying polluted water and degrading organic contaminants has attracted increasing attention. The generation of singlet oxygen (1O2) and superoxide radicals (O2•-) remains a key challenge for achieving high catalytic performance. Herein, a range of metal-organic frameworks (MOFs), denoted as {[MBPDC)]·H2O}n (M = Fe2+ (MOF 1), Co2+ (MOF 2), and Ni2+ (MOF 3); H2BPDC = 2,2'-bipyridine-5,5'-dicarboxylic acid), served as an efficient peroxymonosulfate (PMS) activator for the regioselective oxidation of organic pollutants. Photocatalytic experiments revealed that MOF 2 exhibited superior degradation efficiency toward Rhodamine B (RhB), achieving 99.4% removal within 12 min, significantly faster than MOF 1 (4.5%) and MOF 3 (10.0%). Notably, MOF 2 demonstrated excellent reusability and structural robustness over five consecutive cycles. Through integrated radical scavenging tests and electron paramagnetic resonance (EPR) spectroscopy, 1O2 and O2•- were determined to be the key reactive oxygen species driving the degradation process. The outstanding durability and anti-interference capacity of MOF 2 underscore its practical potential for cost-effective and robust environmental remediation applications.

Efficient peroxymonosulfate (PMS) activation by visible-light-driven formation of polymorphic amorphous manganese oxides

Development of a heterogenous catalyst FeWO4/Cu2S as peroxymonosulfate activator for effective sulfachloropyridazine elimination

Transition metal induced interfacial d-p orbital hybridization boosting biochar for efficient fenton-like decontamination

The regulation of peroxymonosulfate (PMS) activation by photo‐assisted heterogeneous catalysis is under in‐depth investigation with potential as a replaceable advanced oxidation process in water purification, yet it remains a significant challenge. Herein, we demonstrate a strategy to construct polyethylene glycol (PEG) well‐coupled dual‐defect VO−M–Co3O4@CNx S‐scheme heterojunction to degrade organic pollutants without aeration, which dramatically provides abundant active sites, excellent photo‐thermal property, and distinct charge transport pathway for PMS activation. The degradation rate of VO−M−Co3O4@CNx in anaerobic conditions shows a higher efficient rate (4.58 min−1 g−2) than in aerobic conditions (1.67 min−1 g−2). Experimental evidence reveals that VO−M−Co3O4@CNx promotes more rapid redox conversion of photoexcited electrons induced by defects with PMS under anaerobic conditions compared to aerobic conditions. Additionally, in situ experiments and DFT provide mechanistic insights into the regulation pathway of PMS activation via synergistic defect‐induced electron, revealing the competitive effect between O2 and PMS over VO−M−Co3O4@CNx during the reaction process. The continuous flow reactor and flow cytometry results demonstrated that the VO−M−Co3O4@CNx/PMS/Vis system has remarkably enhanced stability and purification capability for removing organic pollutants. This work provides valuable insights into regulating the heterologous catalysis oxidation process without aeration through the photoexcitation synergistic PMS activation.

The regulation of peroxymonosulfate (PMS) activation by photo-assisted heterogeneous catalysis is under in-depth investigation with potential as a replaceable advanced oxidation process in water purification, yet it remains a significant challenge. Herein, we demonstrate a strategy to construct polyethylene glycol (PEG) well-coupled dual-defect VO-M-Co3O4@CNx S-scheme heterojunction to degrade organic pollutants without aeration, which dramatically provides abundant active sites, excellent photo-thermal property, and distinct charge transport pathway for PMS activation. The degradation rate of VO-M-Co3O4@CNx in anaerobic conditions shows a higher efficient rate (4.58 min-1 g-2) than in aerobic conditions (1.67 min-1 g-2). Experimental evidence reveals that VO-M-Co3O4@CNx promotes more rapid redox conversion of photoexcited electrons induced by defects with PMS under anaerobic conditions compared to aerobic conditions. Additionally, in situ experiments and DFT provide mechanistic insights into the regulation pathway of PMS activation via synergistic defect-induced electron, revealing the competitive effect between O2 and PMS over VO-M-Co3O4@CNx during the reaction process. The continuous flow reactor and flow cytometry results demonstrated that the VO-M-Co3O4@CNx/PMS/Vis system has remarkably enhanced stability and purification capability for removing organic pollutants. This work provides valuable insights into regulating the heterologous catalysis oxidation process without aeration through the photoexcitation synergistic PMS activation.

Single atom site catalysts (SACs) with atomically dispersed active sites can be expected to be potential ideal catalysts for accurately modulating the persulfate activation pathway during the water remediation process because of their well-defined structure and the maximum metallic atom utilization. In this paper, a series of Cu SACs with different coordination environments were synthesized to elaborately regulate the peroxymonosulfate activation pathway in AOPs to clarify active species generation and transformation in water remediation. The degradation rate constants (kobs) of Cu-N2, Cu-N3, and Cu-N4 were 0.028, 0.021, and 0.015 min-1, respectively. Cu-N2 SACs exhibited a noticeable enhanced performance for bisphenol A (BPA) removal from water compared to that of the Cu-Nx SACs (x = 3, 4), accompanied by peroxymonosulfate (PMS) activation pathway variation. As shown by experimental and theoretical results, the PMS activation pathway was transformed from ROS to electron transfer with nitrogen coordination numbers decreasing from 4 to 2, which can be ascribed to the uneven charge distribution of Cu sites as well as upshifts in the d-band center, and thereby optimized electron transfer for PMS activation. Furthermore, the increasing nitrogen vacancies of single Cu site catalysts can also result in more unoccupied 3d orbitals of Cu atoms in SACs, thereby improving the intermediates' (PMS and BPA) adsorption-desorption process and BPA removal performance. These findings provided a beneficial approach for the coordination number regulation of SACs in water remediation.

Dual metal ions/BNQDs boost PMS activation over copper tungstate photocatalyst for antibiotic removal: Intermediate, toxicity assessment and mechanism

Copper in LaMnO3 to promote peroxymonosulfate activation by regulating the reactive oxygen species in sulfamethoxazole degradation

Surface oxygen vacancy inducing peroxymonosulfate activation through electron donation of pollutants over cobalt-zinc ferrite for water purification

Diatomic "catalytic/co-catalytic" Fe/Mo catalysts promote Fenton-like reaction to treat organic wastewater through special interfacial reaction enhancement mechanism.

Intensification of van der Waals interaction for efficient peroxymonosulfate activation and accuracy re-evaluation of quenching experiments for reactive oxidation species identification