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Reactive membrane filtration, integrating membrane technology with catalytic processes, offers a promising avenue for efficiently generating and utilizing active species in environmental remediation. Herein, a dual-atom Co-Mn site achieved through axial coordination on N-doped graphene catalyst (sp -CoMn@NG) has been developed and applied in membrane filtration for the targeted removal of specific pollutants. Experimental investigations, alongside density functional theory (DFT) calculations, have substantiated that axial coordination can effectively reduce the adsorption energy and activation barrier of PMS, thereby facilitating nearly 100% conversion of PMS to 1O 2 and enhancing catalytic performance. Mechanistic studies further elucidate the 1O 2 production mechanism through a superoxide-mediated chain reaction at the axially coordinated Co-Mn center, as well as the inactivation mechanism of catalytic membranes via the addition reaction of 1O 2 and phenolic-hydroxyl compounds. This research underscores the intelligent prefabrication of axial coordination in dual-atomic-site catalysts, offering an efficient approach for scalable 1O 2 production in reactive membrane filtration. [Display omitted] • Axially coordinated dual-atomic-sites catalyst was prepared via a facile method. • Nearly 100% PMS converted to 1O 2 on axial dual-atomic-sites. • Rate constant increased over 150 times for targeted compound removal. • Superoxide-mediated 1O 2 production mechanism was clarified. • Accumulation of 1O 2 -induced addition compounds leads to active site inactivation. [ABSTRACT FROM AUTHOR]

A perovskite LaCoO 3 functionalized Ti 4 O 7 reactive electrochemical membrane (REM) was developed for electro-enhanced peroxymonosulfate (PMS) activation (E-REM-PMS), addressing limitations in wastewater treatment efficiency, reusability, and interference resistance. It achieved 100% carbamazepine (CBZ) removal at a rate constant of 39.69 min−1, 233 and 23 times of electro-REM (E-REM) system without PMS and REM-PMS system without electricity. In-situ Fourier transform infrared spectroscopy (FTIR) highlighted the promotion of electro-activation on PMS, while density functional theory (DFT) calculations elucidated mechanism differences under three adsorption configurations. 1O 2 (2.97×10−9 M), SO 4 • − (2.09×10−11 M) and •OH (7.36×10−12 M) dominated the E-REM-PMS system, consistent with sequence of reactive species by DFT results. Continuous treatment of pharmaceutical wastewater confirmed 100% CBZ removal and 60%-70% TOC mineralization at ultrahigh water flux (642.86 L/m2·h) with minimal energy consumption (0.01 kWh/m3·order). This work proposed a high-performance and anti-fouling REM, offering an efficient and economical solution for wastewater treatment. [Display omitted] • LaCoO 3 /T 4 O 7 REM achieved ultrafast CBZ removal in 10.6 s (100 %, k = 39.69 min−1). • ROS quantification and DFT calculation revealed the main role of 1O 2 , SO 4 • − and •OH. • In-situ FTIR proved synergistic effect of LaCoO 3 /T 4 O 7 REM, electric field and PMS. • This work showed high water flux (636.62 L/m2·h) with minimal energy consumption. • Long-term test in pharmaceutical wastewater clarified its practical applicability. [ABSTRACT FROM AUTHOR]

Photoelectrocatalytic (PEC) system harnesses solar energy for chemical reactions, representing a highly promising renewable energy-based technology for water purification. Herein, we design a novel separated PEC system that integrates water purification on an oxygen vacancy-rich black TiO 2 nanocones (b-TiO 2-x) photoanode with two-electron O 2 reduction reaction for H 2 O 2 production on a natural air diffusion cathode. This integration benefits from thermodynamic advantages, synergy effects and enhanced •OH production, thus exhibiting superior water purification (98.32%, 0.064 min−1) and H 2 O 2 production (6.83 μmol/h/cm2) at ultra-low applied cell voltage of 0.5 V, with the energy consumption of only 0.034 kWh/m3 wastewater treated, where the simultaneous production of value-added H 2 O 2 could fully compensate for the electric cost of the system. Notably, even under real sunlight irradiation, this system achieves efficient water purification and H 2 O 2 production without additional energy consumption, offering a cost-effective and environmental-benign strategy for the dual purpose of water purification and resourcization. [Display omitted] • Novel PEC integrating b-TiO 2-x nanocones photoanode and NADE is reported. • It achieves efficient water purification and synchronous H 2 O 2 production at only 0.5 V. • Anode photovoltage compensation and enhanced electrons transfer enhance H 2 O 2 production. • The mechanisms of oxygen vacancy for efficient H 2 O activation to •OH are illustrated. • The integration achieves solar-PEC with zero electricity consumption under real sunlight irradiation. [ABSTRACT FROM AUTHOR]

A novel photoelectrocatalytic (PEC) system consisting of S-scheme MgO/g-C 3 N 4 photoanode and modified carbon felt (MCF) cathode was designed for efficient degradation of tetracycline, in which photoanode had both efficient photocatalytic performance and activation of H 2 O 2 produced by the MCF cathode. After 30 min of LED irradiation, the PEC system could completely remove tetracycline at cathodic bias of −0.5 V (vs. Ag/AgCl), and the degradation rate constants were 5.3 and 1.5 times that of electrocatalysis and photocatalysis. The charge transfer mechanism of S-scheme MgO/g-C 3 N 4 was verified by experimental studies and DFT calculations. Mg-N coordination was the key to activate H 2 O 2 to produce singlet oxygen (1O 2) and hydroxyl radicals (•OH). The PEC system had excellent degradation performance at pH ranges 4–10, which solved the bottleneck that Fenton system is effective at narrow pH range. This study provides new ideas for preparation of bifunctional photoanodes and new insights into the PEC process. [Display omitted] • Novel MgO/g-C 3 N 4 S-scheme heterojunction photoanode were synthesized. • Efficient tetracycline removal was achieved by the photoelectrocatalytic system. • The photoanode could activate H 2 O 2 to 1O 2 and •OH, and perform well at pH 4–10. • Efficient charge transfer and separation in S-scheme MgO/g-C 3 N 4 was verified. • It provides the coupling of photocatalysis with Fenton-like process without transition metals. [ABSTRACT FROM AUTHOR]

Designing and constructing novel discrete architecture for quantum dots modified ultrathin hollow nanotube Bi 2 Sn 2 O 7 /Bi 4 O 5 I 2 S-scheme heterojunctions for the first time in this work is an ideal strategy to improve the photocatalytic activity. As expected, the Bi 2 Sn 2 O 7 /Bi 4 O 5 I 2 heterojunction exhibited outstanding performance of degradation bisphenol A (BPA), the rate constant of Bi 2 Sn 2 O 7 /Bi 4 O 5 I 2 heterojunction was 1.7 and 41.8 times higher than that of Bi 4 O 5 I 2 and Bi 2 Sn 2 O 7 , respectively. The promoted activity could be attributed to the spatial separation of photogenerated carriers as well as redox reaction sites due to the discrete structure, and the enhanced charge separation due to the S-scheme mechanism via Bi-O channels as derived from DFT calculations. Furthermore, Bi 2 Sn 2 O 7 /Bi 4 O 5 I 2 heterojunction exhibited unprecedented ultra-efficient in BPA degradation compared to other published Bi-based catalysts, and excellent performance under actual sunlight contributes to its prospective practical application. This strategy affords a novel approach for fabricating discrete S-scheme heterojunctions photocatalysts with high-efficiency, strong-stable, and sustainable. [Display omitted] • Novel quantum dots modified Bi 2 Sn 2 O 7 /Bi 4 O 5 I 2 S-scheme heterojunction was fabricated. • The discrete structure realizes separation of photogenerated e- and h+ and redox reaction sites. • The formed Bi-O bonds strengthen the interfacial coupling and work as fast electron transfer paths. • Bi 2 Sn 2 O 7 /Bi 4 O 5 I 2 heterojunction exhibited unprecedented ultra-efficient in BPA degradation. [ABSTRACT FROM AUTHOR]

Heterogeneous electro-Fenton (hetero-EF) technology represents a promising and safe approach to water treatment. However, conventional hetero-EF catalysts still face the challenges of removing contaminants selectively and operating efficient in complex water quality. We proposed a novel system utilizing amorphous CoS x (A-CoS x) that overcame these limitations. This material generated only singlet oxygen (1O 2), a highly specific oxidant, for contaminants degradation. Unlike traditional crystalline catalysts, A-CoS x efficiently utilized hydrogen peroxide (H 2 O 2) to directly produce 1O 2 , exhibiting high catalytic activity across a wide pH range (3.0–11.0). The formation mechanism of 1O 2 was confirmed through experimental investigations, density functional theory (DFT) calculations, and advanced characterization techniques. This system effectively degraded contaminants even in complex water with interferences and enabled selective targeting of pollutants with electron-donating groups. This innovative approach using amorphous materials offers a promising strategy for the regulation of ROS and enabling selective contaminant removal in water treatment. [Display omitted] • The role of amorphous CoS x catalyst for 1O 2 generation in hetero-EF system was revealed. • A-CoS x achieved nearly 100 % H 2 O 2 utilization efficiency and 1O 2 conversion in the hetero-EF system. • The A-CoS x /hetero-EF system demonstrated exceptional efficiency and selectivity in water decontamination. [ABSTRACT FROM AUTHOR]

Abstract: Bimodal nanocrystalline mesoporous TiO2 powders with high photocatalytic activity were prepared by a hydrothermal method using tetrabutylorthotitanate (TiO(C4H9)4, TBOT) as precursor. The as-prepared TiO2 powders were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS) and N2 adsorption–desorption measurements. The photocatalytic activity of the as-prepared TiO2 powders was evaluated by the photocatalytic degradation of acetone (CH3COCH3) under UV-light irradiation at room temperature in air. The effects of hydrothermal temperature and time on the microstructures and photocatalytic activity of the TiO2 powders were investigated and discussed. It was found that hydrothermal treatment enhanced the phase transformation of the TiO2 powders from amorphous to anatase and crystallization of anatase. All TiO2 powders after hydrothermal treatment showed bimodal pore-size distributions in the mesoporous region: one was intra-aggregated pores with maximum pore diameters of ca. 4–8nm and the other with inter-aggregated pores with maximum pore diameters of ca. 45–50nm. With increasing hydrothermal temperature and time, the average crystallite size and average pore size increased, in contrast, the Brunauer-Emmett-Teller (BET) specific surface areas, pore volumes and porosity steadily decreased. An optimal hydrothermal condition (180°C for 10h) was determined. The photocatalytic activity of the prepared TiO2 powders under optimal hydrothermal conditions was more than three times higher than that of Degussa P25. [Copyright &y& Elsevier]