Substrate Adsorption Research Articles

Porous covalent organic framework liquid for boosting CO2 adsorption and catalysis via dynamically expanding effect

Abstract The features of intrinsic porosity and fluidity endow porous liquids (PLs) unique properties and performances but the preparation of PLs remains challenging due to the difficulty in liquefying and keeping porous features at the same time. Herein, we develop a stepwise surface functionalization and ion exchange strategy to achieve a rare example of flexible covalent organic framework (COF) based porous liquid (COF-PLs). By coating the outer surface of the judiciously selected three-dimensional flexible COF-301 with an imidazolium salt corona, followed by liquefaction using the anion canopy potassium poly(ethylene glycol) sulfonate (PEGS) via electrostatic interactions to obtain the flexible porous liquid COF-301-PL. Theoretical calculations and CO2 adsorption experiments reveal that the cavities of COF-301-PL undergo dynamic adjustments in response to changes in CO2 pressure. The dynamic expansion effect not only can provide additional gas adsorption capacity (7.04 mmol/g at 40 bar) but also facilitate the mass transfer of gas molecules during the catalytic process. Consequently, COF-301-PL exhibits superior catalytic efficiency for the conversion of CO2 into cyclic carbonate by a factor of 24 and 17 compared to those of PEGS and COF-301 solid counterpart, respectively. The optimization of substrate adsorption and mass transfer conditions consequently improves the overall efficiency of catalytic reactions. This work offers a new perspective on the preparation of PLs and their large potential application for gas adsorption and catalysis.

Local Symmetry-Broken Single Pd Atoms Induced by Doping Ag Sites for Selective Electrocatalytic Semihydrogenation of Alkynes.

Engineering the local coordination environment of single metal atoms is an effective strategy to improve their catalytic activity, selectivity, and stability. In this study, we develop an asymmetric Pd-Ag diatomic site on the surface of g-C3N4 for the selective electrocatalytic semihydrogenation of alkynes. The single Pd atom catalyst, which has a locally symmetric Pd coordination, was inactive for the semihydrogenation of phenylacetylene in a 1 M KOH and 1,4-dioxane solution at an applied potential of -1.3 V (vs RHE). In sharp contrast, doping Ag sites into single Pd atom catalyst to form paired Pd-Ag diatomic sites with asymmetric Pd coordination substantially enhanced the reaction, resulting in a high conversion (>98%) with exceptional time-independent selectivity to styrene under identical conditions. Characterization and theoretical calculations reveal that the introduction of a Ag site into single Pd atoms disrupts their symmetry coordination by forming Pd-Ag bonds with N2-Pd-Ag-N configuration, thereby modulating the electronic and geometric structures of Pd sites, which in turn benefits the adsorption and activation of substrate and lowers energy barrier for the rate-determining step of semihydrogenation, ultimately enhancing the electrocatalytic reaction. This work provides a facile and powerful strategy for the design of advanced catalysts by tuning the local coordination environment for selective catalysis.

Multifunctional Roles of Ionic Microenvironments in the Preparation, Modification, and Application of g‐C3N4

AbstractAs a visible light‐responsive metal‐free polymer semiconductor, graphitic carbon nitride (g‐C3N4) has garnered increasing attention in photocatalysis but needs structural modification and functional enhancement. Recently, the rational design of ionic microenvironments (IMEs) by leveraging the tunability of various ions to endow catalysts with tailored functionalities has been elevated to a hot direction. To elucidate their respective effects on g‐C3N4, IMEs are categorized into three types, namely plasma IMEs, organic IMEs, and inorganic IMEs, according to the criteria of external field dependence, cation type, and application scenarios. These promotions include facilitated preparation, diversified modifications, and improved efficiencies. First, IMEs participate in constructing a functionalized microenvironment through dynamic interactions with the precursor during the preparation, facilitating structural customization, crystal nucleation and growth, surface performance enhancement, and process cleanliness. Second, IMEs create a tunable microenvironment for post‐modification of g‐C3N4, functioning as an electron reservoir, structural modifier, substrate adsorbent, and stabilizer. Lastly, through the synergistic effect between IME and g‐C3N4, they achieve targeted product regulation, enhanced chemical stability, efficient substrate adsorption, and improved application potential in fields like catalysis, energy storage, and gas adsorption. Also, the limitations, challenges, and prospects of IME strategies are discussed, offering systematic insights into IMEs‐based structure‐activity relationships of g‐C3N4.

Simultaneous Coproduction of Xylonic Acid and Xylitol: Leveraging In Situ Hydrogen Generation and Utilization from Xylose.

Pentose oxidation and reduction, processes yielding value-added sugar-derived acids and alcohols, typically involve separate procedures necessitating distinct reaction conditions. In this study, a novel one-pot reaction for the concurrent production of xylonic acid and xylitol from xylose is proposed. This reaction was executed at ambient temperature in the presence of a base, eliminating the need for external gases, by leveraging Pt-supported catalysts. Initial experiments using commercially available metal-supported carbon catalysts validated the superior activity of Pt. However, a notable decline in recycling performance was observed in Pt/C, which is attributed to the sintering of Pt nanoparticles. In contrast, the synthesized Pt-supported ZrO2 catalysts exhibited enhanced recycling performance because of the strong metal-support interaction between Pt and the ZrO2 support. Furthermore, mechanistic insights and density functional theory calculations show that product desorption involves a significantly higher energy barrier compared to substrate adsorption and hydrogenation, highlighting an efficient transfer hydrogenation mechanism leading to equivalent yields of both xylonic acid and xylitol. This study introduces a promising approach for the simultaneous production of sugar-derived acids and alcohols, with implications for sustainable catalysis and process optimization.

Imaging Dihydrogen Bond-Driven Assembly of Borazine on Au(111).

Dihydrogen bonding (DHB) is a peculiar type of attractive interaction occurring between a partially positively charged hydrogen atom and a partially negatively charged hydrogen atom. Borazine represents a prototypical molecule exhibiting dihydrogen bonding in both gas phase, as well as in its crystalline form. For borazine assemblies on solid surfaces, a direct observation and characterization of dihydrogen bonding has remained elusive, possibly due to an intricate interplay of substrate-molecule and intermolecular interactions. Here we present evidence of dihydrogen bonding occurring in borazine assemblies on a Au(111) surface. By means of low-temperature scanning tunneling microscopy, we unveiled distinct configurations, exhibiting single and double dihydrogen bonding. Density functional theory calculations elucidate the interplay between substrate adsorption and intermolecular interactions to stabilize the formation of borazine dimers on Au(111). The dimers constitute the building blocks for the formation of larger assemblies.

High-Performance Photocatalytic Degradation of Aromatic Compounds Using Co-MOF-74/ZnIn2S4/CNF Aerogels with Enhanced Charge Separation and Photothermal Synergy

Although photocatalytic degradation using semiconductor materials has been widely studied, there are still challenges such as slow reaction kinetics and complex synthesis process. To overcome these problems, Co-MOF-74@ZnIn2S4@CNF composite aerogel was developed in this study, which significantly improved the photocatalytic efficiency. This novel structure integrates three key functions: 1) the one-dimensional Co-MOF-74-NTs nanotube enhances carrier mobility based on its high aspect ratio; 2) the Co-MOF-74@ZnIn2S4 heterojunction facilitates charge separation for efficient generation of reactive oxygen species; 3) the porous cellulose aerogel promotes the adsorption of substrates and improves the photothermal effect due to its intrinsic thermal conductivity and insulation, and will facilitate effective charge separation. This combined functionality resulted in highly efficient degradation of paraxylene, with 91.6% of degradation efficiency and 68.79% of mineralization rate within 3h under simulated sunlight. Several experiments demonstrated that the Co-MOF-74@ZnIn2S4@CNF aerogel possessed strong stability and effective catalytic properties for a variety of aromatic compounds. This study introduces a new photocatalytic system combining heterogeneous structure and photothermal effect to enhance charge transfer, providing an efficient solution for photothermal-assisted Aromatic Compounds degradation.

Synthesis of aviation biofuel precursors from biomass-derived ketones: Substrate adsorption configuration-catalytic activity

The production of aviation biofuel precursors from biomass-derived ketones by heterogeneous catalysis has been hindered by the low catalytic activity. Herein, a series of Cu-doped metal oxide catalysts were prepared for the conversion of biomass-derived ketones to aviation biofuel precursors. Solvent-free cyclopentanone conversion via aldol condensation reached 91.1 % over Cu/Al2O3 with 100 % selectivity toward dimer and trimer oxygenated species, all of which are aviation biofuel precursors. This catalyst primarily contains Cu2O and Cu nanoparticles which are uniformly dispersed across the Al2O3 surface. From in situ DRIFTS and DFT results, the incorporation of Cu species onto Al2O3 not only increased the diversity of Lewis acidic sites, but also changed the adsorption of C = O groups, which lead to the increased aldol condensation activity of Cu/Al2O3. This study provides insight on the design of heterogeneous catalysts suitable for the solvent-free synthesis of aviation biofuel precursors from biomass-derived ketones.

Trace Iron-Modified CeO₂-Supported Core-Shell CoO@Co Catalyst for Selective Conversion of Furfural to 1,5-Pentanediol.

In the conversion of furfural using non-noble metal catalysts, preferential cleavage of the C2-O bond followed by hydrogenation of the C=C bond facilitates selective access to valuable 1,5-pentanediol (1,5-PeD). Herein, we developed CeO₂ loaded core-shell CoO@Co nanoparticle catalysts. Adjusting Co loading, Fe doping, and reduction temperature improved reaction efficiency. 7Co-0.2Fe/CeO₂ catalysts reduced at 500 °C demonstrated optimal performance. 1,5-PeD produced at 54.76 mmol/gCo/h, representing the top activity levels among the reported catalysts. H₂-TPR, XRD, HAADF-STEM, FT-IR, XPS, and XANES were employed to investigate the catalyst structure-activity relationship. Co2+ cleaves furan ring C-O bond, Co⁰ promotes double-bond hydrogenation. The CoO@Co structure favors the desired 1,5-PeD production route. Trace Fe species optimize the Co2+/Co⁰ ratio, enhance the substrate adsorption, and inhibit the furan ring saturation. These findings emphasize the importance of fine-tuning catalyst structure and composition for selectivity improvement.

Efficient Hydrodeoxygenation of Lignin-Derived Phenolic Compounds Over Ru-Based Catalyst with Biochar and Al2O3 as Composite Support.

Hydrodeoxygenation (HDO) is a common strategy for upgrading lignin-derived phenolic compounds into high-quality liquid fuels, and the support rational design of HDO catalysts is critical to achieve a good reaction performance. This work proposed a novel Ru-based catalyst with biochar and Al2O3 as composite support. The addition of biochar can enlarge the porous structure, and the addition of Al2O3 can enhance the acid property of the support. By regulating the content of biochar and Al2O3 components, Ru/CA-2 catalyst achieved the best HDO performance of lignin-derived phenolic compounds, with the optimal component balance of 50 %C and 50 %Al2O3. This catalyst possesses the high Ru metal dispersion (1.38 nm particle size) to activate the hydrogen source, the moderate acid property to suppress carbon deposition and the abundant oxygen vacancy to promote substrate adsorption at the same time. 99.9 % conversion of guaiacol is obtained at 230 °C, with 99.9 % selectivity towards cyclohexane. Ru/CA-2 catalyst also has a good recyclability, with no obvious activity loss after five runs. Furthermore, in the application of catalytic lignin-oil HDO, the content of hydrocarbons increase from 10.7 % to 95.7 %, showing great potential on the industrial usage.

Study on the methanol aqueous phase reforming performances over Pt/CeO2 catalysts: The effect of CeO2 morphologies and oxygen vacancies

CeO2-supported catalysts have been extensively studied for hydrogen production via aqueous phase reforming of methanol (APRM) although several issues remain unclear, such as the influence of different morphologies on catalytic performance and the role of their oxygen vacancies in enhancing hydrogen yield. In this study, CeO2 with three distinct morphologies were synthesized, and platinum was loaded onto these supports via a photoreduction method to produce highly-dispersed catalysts designated as Pt/CeO2-R (rod-shaped), Pt/CeO2-C (cubic) and Pt/CeO2-O (octahedral) respectively. A series of APRM experiments suggested that Pt/CeO2-R exhibited the highest hydrogen production capacity (146.2 mmol-H2/gcat.). This superior performance is likely to attribute to the highly-dispersed Pt on the rod-shaped CeO2 support, which provides a substantial number of active metal sites, promoting the efficient adsorption and activation of methanol throughout the process. The anchoring effect of platinum on support surface and redox properties of Pt species were also thoroughly investigated with various characterization techniques. Further analysis revealed a strong correlation between turnover frequency (TOF) and the presence of oxygen vacancies on Pt/CeO2. Notably, abundant oxygen vacancies on catalyst enhanced substrate adsorption and the rapid conversion of CO* intermediates adsorbed on platinum, which accelerated the water-gas shift (WGS) reaction through a faster redox pathway, leading to higher hydrogen production with low CO selectivity.

Synergistic regulation of dual thresholds: Hydroxyl occupancy and carbon species in the targeted catalytic hydrocracking of lignite

The preparation of carbon-based catalyst supports from low-grade lignite, followed by its self-catalytic hydrocracking to produce lignite-derived aromatic compounds, is crucial for achieving efficient lignite utilization and expanding aromatic compound sources. During lignite catalytic hydrocracking, the uncontrolled diffusive migration of active hydrogen (H*) and insufficient protection of aromatic rings reduce the yield of aromatic compounds. Using Heishan lignite as the raw material, we employed a relay process of thermal-induced self-assembly and oxidation-mediated carbon distortion for fabricating the Co3O4/AC&GC-S-600 composite material, which features an optimal hydroxyl occupancy ratio and a balanced combination of amorphous carbon/graphite carbon (AC/GC) types. The optimal hydroxyl occupancy threshold balances Co3O4 dispersion and hydrophilicity, facilitating the efficient formation and directional migration of H* through synergistic interaction between Co3O4 and H2O. The adequate threshold of AC/GC ratio regulates substrate adsorption, activation, and inhibition of aromatic hydrogenation, enhancing selective C–O bridge bond cleavage and preserving the unsaturation of aromatic rings. The synergistic regulation of dual thresholds promotes the rapid formation and the directional migration of H*, enabling efficient conversion of Heishan lignite to aromatic compounds (45.8% conversion, 80.8% selectivity) under mild conditions. Characterization techniques, experimental analyses, kinetic studies, and density functional theory calculations confirm that thermally induced self-assembly and oxidation-mediated carbon distortion are crucial for redistributing the carbon framework of the Heishan lignite matrix and regulating the optimal dual thresholds of hydroxyl occupancy and AC/GC types, which are essential for the catalytic hydrocracking of Heishan lignite to aromatic compounds. This strategy provides a scientific basis for selective catalytic production of lignite-based aromatic compounds, thereby supporting its clean and efficient utilization.

Efficient catalytic oxidation of xylose to formic acid with the oxygen vacancies of CeO2 promoted the vanadium catalysts anchored on biochar

The catalytic oxidation of carbohydrates for the preparation of formic acid (FA) is an prominent route for high-value utilisation of biomass. Reforming xylose, a biomass derivative, into FA with high efficiency is essential for the advancement of non-homogeneous V-type catalysts. Here, we present the self-assembly of V and Ce onto a cellulose pulp for the synthesis of oxygen vacancy (Ov)-rich non-homogeneous-bimetallic catalysts (5Ce-VOx/BC-600). Under the optimised conditions, 71.46 % FA was obtained, which far exceeded the catalytic performance of the single-metal catalyst. Furthermore, the 5Ce-VOx/BC-600 catalyst showed excellent stability and reusability. Kinetic studies revealed that glyceric and glycolic acids served as the pivotal intermediates, undergoing subsequent deacidification and oxidation processes to yield FA and CO2. The analysis of the catalytic mechanism indicated that the incorporation of Ce enhanced the quantity of acidic sites and the concentration of Ov in the 5Ce-VOx/BC-600 catalyst, which promoted substrate adsorption and O2 activation. Meanwhile, the catalyst showed high lattice oxygen (OL) mobility and assisted the redox cycle of V5+/V4+ to oxidise xylose to FA. Significantly, the synergistic effect of Ce, V species and Ov enhances the OL mobility of the catalysts, thus promoting the efficient oxidation of xylose. The catalytic system was further extended to the oxidation of other biomass derivatives to FA, demonstrating excellent catalytic performance.

CdWO4 Sub‐1 nm Nanowires for Visible‐Light CO2 Photoreduction

AbstractQuantum size effect usually causes energy level splitting and band broadening as material size decreases. However, this may change again by the surface adsorbents, doping and defects, which rarely attracts much attention. Herein, CdWO4 sub‐1 nm nanowires (SNWs) with oleylamine adsorption, PO43−‐doping and oxygen defects are synthesized by combining Cd(CH3COO)2, H3PW12O40 (PW12) and oleylamine (abbreviated as PO43−‐CdWO4‐X SNWs). Compared with bulk CdWO4, they exhibit unexpected absorption spectra (extended from 292 nm to 453 nm) and band gap (reduced from 4.25 eV to 2.74 eV), thus bringing remarkable visible‐light CO2 photoreduction activity. Under 410 nm LED light irradiation, PO43−‐CdWO4‐40 SNWs exhibit the highest photocatalytic performance with a CO2‐to‐CO generation rate of 1685 μmol g−1 h−1. Density functional theory (DFT) calculations demonstrate the adsorbed oleylamine raises the valence band and enhances the adsorption of reaction substrate and intermediates, thus decreasing their reduction energy barriers. Furthermore, PO43−‐doping and oxygen defects will generate defect energy band below the conduction band of PO43−‐CdWO4‐40 SNWs, resulting in remarkable visible light absorption and superior photocatalytic CO2 reduction performance. This work highlights the significant impacts of surface adsorbents, doping and defects on the physicochemical and catalytic properties of sub‐nano materials.

D-Band-Center-Engineered Platinum-Based Nanozyme for Personalized Pharmacovigilance.

A high-efficiency PtZnCd nanozyme was screened with density functional theory (DFT) and unique d-orbital coupling features for sensitive enrichment and real-time analysis of CO-releasing molecule-3 (CORM-3). Multicatalytic sites in the nanozyme showed a high reactivity of up to 72.89 min-1 for peroxidase (POD)-like reaction, which was 2.2, 4.07, and 14.67 times higher than that of PtZn (32.67 min-1), PtCd (17.89 min-1), and Pt (4.97 min-1), respectively. Normalization of the catalytic sites showed that the catalytic capacity of the active site in PtZnCd was 2.962 U μmol-1, which was four times higher than that of a pure Pt site (0.733 U μmol-1). DFT calculations showed that improved d-orbital coupling between different metals reduces the position of the center of the shifted whole d-band relative to the Fermi energy level, thereby increasing the contribution of the sites to the electron transfer from the active center, accompanied by enhanced substrate adsorption and intermediate conversion in the catalytic process. The potential adsorption principle and color development mechanism of CORM-3 on PtZnCd were determined, and its practical application in drug metabolism was validated in vitro and in zebrafish and mice models, demonstrating that transition-metal doping effectively engineers high-performance nanozymes and optimizes artificial enzymes.

D‐Band‐Center‐Engineered Platinum‐Based Nanozyme for Personalized Pharmacovigilance

AbstractA high‐efficiency PtZnCd nanozyme was screened with density functional theory (DFT) and unique d‐orbital coupling features for sensitive enrichment and real‐time analysis of CO‐releasing molecule‐3 (CORM‐3). Multicatalytic sites in the nanozyme showed a high reactivity of up to 72.89 min−1 for peroxidase (POD)‐like reaction, which was 2.2, 4.07, and 14.67 times higher than that of PtZn (32.67 min−1), PtCd (17.89 min−1), and Pt (4.97 min−1), respectively. Normalization of the catalytic sites showed that the catalytic capacity of the active site in PtZnCd was 2.962 U μmol−1, which was four times higher than that of a pure Pt site (0.733 U μmol−1). DFT calculations showed that improved d‐orbital coupling between different metals reduces the position of the center of the shifted whole d‐band relative to the Fermi energy level, thereby increasing the contribution of the sites to the electron transfer from the active center, accompanied by enhanced substrate adsorption and intermediate conversion in the catalytic process. The potential adsorption principle and color development mechanism of CORM‐3 on PtZnCd were determined, and its practical application in drug metabolism was validated in vitro and in zebrafish and mice models, demonstrating that transition‐metal doping effectively engineers high‐performance nanozymes and optimizes artificial enzymes.

Use of native macrophyte Echinodorus subalatus for grey water treatment applying alternative bed substrate in constructed wetlands

ABSTRACT Two vertical flow constructed wetland (VFCW 1 and VFCW 2) with native macrophyte Echinodorus subalatus (Mart.) were operated. In VFCW 1, the substrates used were ceramic brick, washed sand, seashells (Anomalocardia brasiliana), and ceramic brick and sand in VFCW 2. The system was operated for 74 days, in batches, with cycles of 168 h, and fed with synthetic grey water. The presence of seashells in VFCW 1 was a differential factor (p < 0) for the removal of anionic surfactant (94.09 ± 7.77%), COD (88.43 ± 5.43%) and total phosphorus (45. 98 ± 9.86%) when compared to VFCW 2. The Langmuir isotherm was used to calculate the substrate adsorption capacity for total phosphorus, anionic surfactant, and COD. The results showed that adsorption on support materials was not the primary mechanism of pollutants removal. From 16S sequencing, it was observed that phylum Firmicutes was the most abundant (96.5%), followed by phylum Proteobacteria (3.5%). The results suggest that using seashells as an alternative substrate improved pollutant removal efficiency.

Trace Ru Incorporation Boosted Co2P Nanorods for Superior Water Electrolysis and Substrate-Paired Electrolysis Toward Value-Added Chemicals in Alkaline Medium.

Electro-valorization of biomass-derived chemicals has ensured sustainable production of value-added products, an effective approach for reducing carbon footprint, through renewable energy. Electrochemical oxidation and reduction reactions in aqueous media using H2O as a potential source for active hydrogenated and oxygenated species fulfill the purpose. In this study, Ru─Co2P nanorods are explored as a bifunctional electrocatalyst toward valorization of Organics at basic media. The in-situ electrogenerated Co3+ and Co4+ species act as active oxidants toward product selectivity. An overpotential of 68mV is found for hydrogen evolution reaction (1m NaOH) with Ru─Co2P. Further, used as cathode, Ru─Co2P effectively reduces furfuraldehyde to furfuryl alcohol and p-nitrophenol to p-aminophenol. Ru doping enables ease of formation of active species both for reduction and oxidation, faster charge transfer between catalyst to absorbates. Density Functional Theory calculation establishes Ru incorporation in Co2P surface results in enhanced adsorption of substrates. Ru doping modulates the electronic structure of Co2P which changes the density of states resulting in faster water dissociation and water splitting. To reach 10mAcm-2 current density only 1.6V is required for water electrolysis, whereas 1.4V is enough for substrate-paired electrolysis with simultaneous oxidation of benzyl alcohol and reduction of p-nitro phenol.

Multi‐Enzyme Mimetic MoCu Dual‐Atom Nanozyme Triggering Oxidative Stress Cascade Amplification for High‐Efficiency Synergistic Cancer Therapy

AbstractSingle‐atom nanozymes (SAzymes) with ultrahigh atom utilization efficiency have been extensively applied in reactive oxygen species (ROS)‐mediated cancer therapy. However, the high energy barriers of reaction intermediates on single‐atom sites and the overexpressed antioxidants in the tumor microenvironment restrict the amplification of tumor oxidative stress, resulting in unsatisfactory therapeutic efficacy. Herein, we report a multi‐enzyme mimetic MoCu dual‐atom nanozyme (MoCu DAzyme) with various catalytic active sites, which exhibits peroxidase, oxidase, glutathione (GSH) oxidase, and nicotinamide adenine dinucleotide phosphate (NADPH) oxidase mimicking activities. Compared with Mo SAzyme, the introduction of Cu atoms, formation of dual‐atom sites, and synergetic catalytic effects among various active sites enhance substrate adsorption and reduce the energy barrier, thereby endowing MoCu DAzyme with stronger catalytic activities. Benefiting from the above enzyme‐like activities, MoCu DAzyme can not only generate multiple ROS, but also deplete GSH and block its regeneration to trigger the cascade amplification of oxidative stress. Additionally, the strong optical absorption in the near‐infrared II bio‐window endows MoCu DAzyme with remarkable photothermal conversion performance. Consequently, MoCu DAzyme achieves high‐efficiency synergistic cancer treatment incorporating collaborative catalytic therapy and photothermal therapy. This work will advance the therapeutic applications of DAzymes and provide valuable insights for nanocatalytic cancer therapy.

Understanding the interaction between soil ORP and enzyme activity: How does wetland type affect constructed wetland performance for the advanced treatment of swine wastewater?

Constructed wetlands (CWs) are widely used for the advanced treatment of swine wastewater. Wetland type is the most critical parameter for engineering applications; therefore, the performance of horizontal/vertical subsurface flow CWs (HSFCWs and VSFCWs) was explored over one year of operation. The effects of five antibiotics (40 μg/L each), copper (Cu, 1.0 mg/L), and their combination on CW performance and soil oxidation–reduction potential (ORP) and enzyme activity were investigated. The annual removal efficiencies of HSFCWs and VSFCWs for total organic carbon (TOC), nitrogen, and phosphorus were 72.03 %–84.49 % and 87.15 %–90.72 %, for antibiotics were 91.35 %–99.52 % and 87.33 %–99.57 %, and for Cu were 97.37 %–97.44 % and 95.52 %–96.85 %, respectively. The CWs removed antibiotics through substrate adsorption, plant absorption, and biodegradation. Total antibiotic residues in HSFCW and VSFCW soils ranged from 6.29 to 17.31 and 24.57 to 589.07 μg/kg, respectively, and enrofloxacin and roxithromycin posed medium and high risks in VSFCW non-rhizosphere soil. The amount of residual antibiotics in Phragmites australis parts was in the order of fibrous roots > rhizomes > aboveground. ORP and enzyme activities were greater in rhizosphere soil than in non-rhizosphere soil and greater in the VSFCWs than in the HSFCWs. CW performance and soil enzyme activities decreased under the stress of antibiotics and coexistence of antibiotics and Cu. These findings advance our knowledge of CW design, elucidate the unique advantages of CWs, and offer efficient operation strategies for swine wastewater advanced treatment, helping researchers recognize the adverse effects of antibiotics on CWs.

CdWO4 Sub-1 nm Nanowires for Visible-Light CO2 Photoreduction.

Quantum size effect usually causes energy level splitting and band broadening as material size decreases. However, this may change again by the surface adsorbents, doping and defects, which rarely attracts much attention. Herein, CdWO4 sub-1 nm nanowires (SNWs) with oleylamine adsorption, PO4 3--doping and oxygen defects are synthesized by combining Cd(CH3COO)2, H3PW12O40 (PW12) and oleylamine (abbreviated as PO4 3--CdWO4-X SNWs). Compared with bulk CdWO4, they exhibit unexpected absorption spectra (extended from 292 nm to 453 nm) and band gap (reduced from 4.25 eV to 2.74 eV), thus bringing remarkable visible-light CO2 photoreduction activity. Under 410 nm LED light irradiation, PO4 3--CdWO4-40 SNWs exhibit the highest photocatalytic performance with a CO2-to-CO generation rate of 1685 μmol g-1 h-1. Density functional theory (DFT) calculations demonstrate the adsorbed oleylamine raises the valence band and enhances the adsorption of reaction substrate and intermediates, thus decreasing their reduction energy barriers. Furthermore, PO4 3--doping and oxygen defects will generate defect energy band below the conduction band of PO4 3--CdWO4-40 SNWs, resulting in remarkable visible light absorption and superior photocatalytic CO2 reduction performance. This work highlights the significant impacts of surface adsorbents, doping and defects on the physicochemical and catalytic properties of sub-nano materials.