Synthetic Leaves Based on Crystalline Olefin-Linked Covalent Organic Frameworks for Efficient CO2 Photoreduction with Water.

We report, for the first time, a new synthetic strategy for the preparation of crystalline two-dimensional olefin-linked covalent organic frameworks (COFs) based on aldol condensation between benzodifurandione and aromatic aldehydes. Olefin-linked COFs can be facilely crystallized through either a pyridine-promoted solvothermal process or a benzoic anhydride-mediated organic flux synthesis. The resultant COF leaf with high in-plane π-conjugation exhibits efficient visible-light-driven photoreduction of carbon dioxide (CO2) with water (H2O) in the absence of any photosensitizer, sacrificial agents, or cocatalysts. The production rate of carbon monoxide (CO) reaches as high as 158.1 µmol g-1 h-1 with near 100% CO selectivity, which is accompanied by the oxidation of H2O to oxygen. Both theoretical and experimental results confirm that the key lies in achieving exceptional photoinduced charge separation and low exciton binding. We anticipate that our findings will facilitate new possibilities for the development of semiconducting COFs with structural diversity and functional variability.

High-Entropy Fluorite Oxide-Modified CaO-Based Sorbent Pellets for Enhanced High-Temperature CO2 Capture.

The calcium looping technology employing CaO-based sorbents is pivotal for capturing CO2 from flue gas. However, the intrinsic low thermodynamic stability of CaO-based sorbents and the requisite molding step induce severe sintering issues, diminishing their cyclic stability. Herein, a high-entropy fluorite oxide (HEFO) inert stabilizer premised on entropy stabilization and synergistic effect strategies is introduced. HEFO-modified, CaO-based sorbent pellets are synthesized via a rapid cigarette butt-assisted combustion process (15 min) combined with the graphite molding method. Post-multiple cycles, their CO2 capture capacity reaches 0.373 g g-1, which is 2.6-fold superior to that of pure CaO, demonstrating markedly enhanced anti-sintering properties. First, the subtle morphological and crystallographic modifications suggest that the inherent entropy stability of HEFO imparts robust thermal resistance. Concurrently, the disordered structure of single-phase HEFO exhibits a high affinity for CaO, resulting in an interface binding energy of -1.83 eV, in sharp contrast to the -0.112 eV of pure CaO, thereby restricting CaO migration. Additionally, the multi-element synergistic effect of HEFO reduces the energy barrier by 0.15 eV, leading to a 40% and 140% increase in carbonation and calcination rates, respectively. This work presents highly efficient and rapidly synthesized CaO-based sorbent pellets, showcasing promising potential for industrial application.

Robust fatigue markers obtained from muscle synergy analysis.

This study aimed to utilize the nonnegative matrix factorization (NNMF) algorithm for muscle synergy analysis, extracting synergy structures and muscle weightings and mining biomarkers reflecting changes in muscle fatigue from these synergy structures. A leg press exercise to induce fatigue was performed by 11 participants. Surface electromyography (sEMG) data from seven muscles, electrocardiography (ECG) data, Borg CR-10 scale scores, and the z-axis acceleration of the weight block were simultaneously collected. Three indices were derived from the synergy structures: activation phase difference, coactivation area, and coactivation time. The indicators were further validated for single-leg landing. Differences in heart rate (HR) and heart rate variability (HRV) were observed across different fatigue levels, with varying degrees of disparity. The median frequency (MDF) exhibited a consistent decline in the primary working muscle groups. Significant differences were noted in activation phase difference, coactivation area, and coactivation time before and after fatigue onset. Moreover, a significant correlation was found between the activation phase difference and the coactivation area with fatigue intensity. The further application of single-leg landing demonstrated the effectiveness of the coactivation area. These indices can serve as biomarkers reflecting simultaneous alterations in the central nervous system and muscle activity post-exertion.

Potential Strategy to Control the Organic Components of Condensable Particulate Matter: A Critical Review.

More and more attention has been paid to condensable particulate matter (CPM) since its emissions have surpassed that of filterable particulate matter (FPM) with the large-scale application of ultralow-emission reform. CPM is a gaseous material in the flue stack but instantly turns into particles after leaving the stack. It is composed of inorganic and organic components. Organic components are an important part of CPM, and they are an irritant, teratogenic, and carcinogenic, which triggers photochemical smog, urban haze, and acid deposition. CPM organic components can aggravate air pollution and climate change; therefore, consideration should be given to them. Based on existing methods for removing atmospheric organic pollutants and combined with the characteristics of CPM organic components, we provide a critical overview from the aspects of (i) fundamental cognition of CPM, (ii) common methods to control CPM organic components, and (iii) catalytic oxidation of CPM organic components. As one of the most encouraging methods, catalytic oxidation is discussed in detail, especially in combination with selective catalytic reduction (SCR) technology, to meet the growing demands for multipollutant control (MPC). We believe that this review is inspiring for a fuller understanding and deeper exploration of promising approaches to control CPM organic components.

Comparison of traditional and suctioning ureteral access sheath during retrograde intrarenal surgery in the treatment of renal calculi.

PURPOSE: This study aims to compare the efficiency and clinical outcomes between the suctioning ureteral access sheath (UAS) group and the traditional UAS group during retrograde intrarenal surgery (RIRS) for kidney stones and explore the impact of suctioning UAS on postoperative infectious complications. METHODS: We retrospectively reviewed the clinical data of 162 patients with kidney stones who underwent RIRS with a traditional UAS (n = 74) or a suctioning UAS (n = 71) between March 2021 and May 2023. RESULTS: The mean operative time in suctioning UAS group (39.03 ± 18.01 s) was significantly shorter than that (49.73 ± 20.77 s) in the traditional UAS group (P = 0.037). The mean postoperative hospital stay was significantly shorter in the suctioning UAS group (1.57 ± 0.82d) compared with the traditional UAS group (2.30 ± 1.6 2 d) (P = 0.032). The instant SFRs were significantly higher in the suctioning UAS group (88.73%) than in the traditional UAS group (75.68%) (P = 0.040). The overall SFR in suctioning UAS group (92.96%) was slightly higher than the traditional UAS group (85.14%). The incidence of overall complications was significantly higher in the traditional UAS group (35.14%) than in the suctioning UAS group (16.90%) (P = 0.013). In multivariate analysis, female patients (OR 0.053, P = 0.018), positive urine WBC (OR 10.382, P = 0.034), operative time > 60 min (OR 20.231, P = 0.032), and the application of traditional UAS (OR 0.042, P = 0.017) were independent risk factors associated with infectious complications. CONCLUSION: We demonstrated that suctioning UAS provided a higher instant SFR and fewer postoperative infectious complications during RIRS, and patients with predictable risk factors for infectious complications could potentially benefit from the use of the suctioning UAS.

Stop moving: MR motion correction as an opportunity for artificial intelligence.

Subject motion is a long-standing problem of magnetic resonance imaging (MRI), which can seriously deteriorate the image quality. Various prospective and retrospective methods have been proposed for MRI motion correction, among which deep learning approaches have achieved state-of-the-art motion correction performance. This survey paper aims to provide a comprehensive review of deep learning-based MRI motion correction methods. Neural networks used for motion artifacts reduction and motion estimation in the image domain or frequency domain are detailed. Furthermore, besides motion-corrected MRI reconstruction, how estimated motion is applied in other downstream tasks is briefly introduced, aiming to strengthen the interaction between different research areas. Finally, we identify current limitations and point out future directions of deep learning-based MRI motion correction.

Modulational instability, generation, and evolution of rogue waves in the generalized fractional nonlinear Schrödinger equations with power-law nonlinearity and rational potentials.

In this paper, we investigate several properties of the modulational instability (MI) and rogue waves (RWs) within the framework of the generalized fractional nonlinear Schrödinger (FNLS) equations with rational potentials. We derive the dispersion relation for a continuous wave (CW), elucidating the relationship between the wavenumber and the instability growth rate of the CW solution in the absence of potentials. This relationship is primarily influenced by the power parameter σ, the Lévy index α, and the nonlinear coefficient g. Our theoretical findings are corroborated by numerical simulations, which demonstrate that MI occurs in the focusing context. Furthermore, we study the RW generations in both cubic and quintic FNLS equations with two types of time-dependent rational potentials, which make both cubic and quintic NLS equations support the exact RW solutions. Specifically, we show that the introduction of these two potentials allows for the excitations of controllable RWs in the defocusing regime. When these two potentials become the time-independent cases such that the stable W-shaped solitons with non-zero backgrounds are generated in these cubic and quintic FNLS equations. Moreover, we consider the excitations of higher-order RWs and investigate the conditions necessary for their generations. Our analysis reveals the intricate interplay between the system parameters and the potential configurations, offering insights into the mechanisms that facilitate the emergence of higher-order RWs. Finally, we find the separated controllable multi-RWs in the defocusing cubic FNLS equation with time-dependent multi-potentials. This comprehensive study not only enhances our understanding of MI and RWs in the fractional nonlinear wave systems, but also paves the way for future research in related nonlinear wave phenomena.

Relationship between the atherogenic index of plasma and the prevalence of kidney stones: insights from a population-based cross-sectional study.

OBJECTIVE: To investigate the association between atherogenic index of plasma (AIP) and kidney stones (KS) occurrence and recurrence. METHODS: Data were obtained from the National Health and Nutrition Examination Survey (NHANES) 2007-2014. Non-pregnant adults who provided complete information on AIP and KS were included in the analyses. AIP was calculated as log (triglyceride/high-density lipoprotein cholesterol). KS was ascertained with questionnaires. Weighted multivariable logistic regression model and restricted cubic spline (RCS) were applied to examine the associations between AIP and KS occurrence and recurrence. RESULTS: A total of 6488 subjects (weighted mean age 43.19 years and 49.26% male) with a weighted mean AIP of 0.66 were included in this study. The multivariable-adjusted OR for nephrolithiasis occurrence across consecutive tertiles was 1.00 (reference), 1.21 (95% CI: 0.90-1.62), and 1.85 (95% CI: 1.39-2.48), respectively. Moreover, each SD increment of AIP was associated with a 50% (OR:1.50, 95% CI: 1.25-1.81) higher risk of nephrolithiasis recurrence. RCSs showed significant and linear dose-response relationships between AIP and nephrolithiasis occurrence (p-overall = 0.006, p-nonlinear = 0.689) and recurrence (p-overall = 0.001, p-nonlinear = 0.848). The positive associations between AIP and nephrolithiasis occurrence and recurrence persisted in sensitivity analyses, suggesting the robustness of the results. CONCLUSION: In the current US nationally representative cross-sectional study, AIP was positively associated with KS occurrence and recurrence.

Identification of Hub Genes and Physiological Effects of Overexpressing the Photosynthesis-Related Gene Soly720 in Tomato under High-CO2 Conditions.

Changes in the atmospheric CO2 concentration influence plant growth and development by affecting the morphological structure and photosynthetic performance. Despite evidence for the macro-effects of elevated CO2 concentrations on plant morphology and yield in tomato, the gene regulatory network and key genes related to cross-regulation have not been reported. To identify the hub genes and metabolic pathways involved in the response of tomato to CO2 enrichment, weighted gene co-expression network analysis was conducted using gene expression profiles obtained by RNA sequencing. The role of the photosynthesis-related gene Soly720 (Solyc01g007720) in CO2-enriched tomato plants was explored. Tomato plants responded to CO2 enrichment primarily through RNA-related pathways and the metabolism of amino acids, fatty acids, and carbohydrates. The hub genes in co-expression networks were associated with plant growth and development, including cellular components and photosynthesis. Compared to wild-type plants, transgenic plants overexpressing the Soly720 gene exhibited 13.4%, 5.5%, 8.9%, and 4.1% increases in plant height, stem diameter, leaf length, and leaf width, respectively, under high-CO2 conditions. The morphological improvements in transgenic plants were accompanied by enhancement of photosynthetic performance in terms of chlorophyll contents, photosynthetic characteristics, and key enzyme activities. This study elucidates the response network of tomato to CO2 enrichment and demonstrates the regulatory role of Soly720 in photosynthesis under high-CO2 conditions.

Delocalized Orbitals over Metal Clusters and Organic Linkers Enable Boosted Charge Transfer in Metal-Organic Framework for Overall CO2 Photoreduction.

The conversion of CO2 to C2 through photocatalysis poses significant challenges, and one of the biggest hurdles stems from the sluggishness of the multi-electron transfer process. Herein, taking metal-organic framework (MOF, PFC-98) as a model photocatalyst, we report a new strategy to facilitate charge separation. This strategy involves matching the energy levels of the lowest unoccupied node and linker orbitals of the MOF, thereby creating the lowest unoccupied crystal orbital (LUCO) delocalized over both the node and linker. This feature enables the direct excitation of electrons from photosensitive linker to the catalytic centers, achieving a direct charge transfer (DCT) pathway. For comparison, an isoreticular MOF (PFC-6) based on analogue components but with far apart frontier energy level was synthesized. The delocalized LUCO caused the presence of an internal charge-separated (ICS) state, prolonging the excited state lifetime and further inhibiting the electron-hole recombination. The presence of ICS state prolongs the excited state lifetime and further inhibits the electron-hole recombination. Moreover, it also induced abundant electrons accumulating at the catalytic sites, enabling the multi-electron transfer process. As a result, the material featuring delocalized LUCO exhibits superior overall CO2 photocatalytic performance with high C2 production yield and selectivity.

Photo-Induced Active Lewis Acid-Base Pairs in a Metal-Organic Framework for H2 Activation.

The establishment of active sites as the frustrated Lewis pair (FLP) has recently attracted much attention ranging from homogeneous to heterogeneous systems in the field of catalysis. Their unquenched reactivity of Lewis acid and base pairs in close proximity that are unable to form stable adducts has been shown to activate small molecules such as dihydrogen heterolytically. Herein, we show that grafted Ru metal-organic framework-based catalysts prepared via N-containing linkers are rather catalytically inactive for H2 activation despite the application of elevated temperatures. However, upon light illumination, charge polarization of the anchored Ru bipyridine complex can form a transient Lewis acid-base pair, Ru+-N- via metal-to-ligand charge transfer, as confirmed by time-dependent density functional theory (TDDFT) calculations to carry out effective H2-D2 exchange. FTIR and 2-D NMR endorse the formation of such reactive intermediate(s) upon light irradiation.

Genetic variation in ZmWAX2 confers maize resistance to Fusarium verticillioides.

Fusarium verticillioides (F. verticillioides) is a widely distributed phytopathogen that incites multiple destructive diseases in maize, posing a grave threat to corn yields and quality worldwide. However, there are few reports of resistance genes to F. verticillioides. Here, we reveal that a combination of two single nucleotide polymorphisms (SNPs) corresponding to ZmWAX2 gene associates with quantitative resistance variations to F. verticillioides in maize through a genome-wide association study. A lack of ZmWAX2 compromises maize resistance to F. verticillioides-caused seed rot, seedling blight and stalk rot by reducing cuticular wax deposition, while the transgenic plants overexpressing ZmWAX2 show significantly increased immunity to F. verticillioides. A natural occurrence of two 7-bp deletions within the promoter increases ZmWAX2 transcription, thus enhancing maize resistance to F. verticillioides. Upon Fusarium stalk rot, ZmWAX2 greatly promotes the yield and grain quality of maize. Our studies demonstrate that ZmWAX2 confers multiple disease resistances caused by F. verticillioides and can serve as an important gene target for the development of F. verticillioides-resistant maize varieties.

Development of [177Lu]Lu-LNC1003 for radioligand therapy of prostate cancer with a moderate level of PSMA expression.

PURPOSE: Evans blue as an albumin binder has been widely used to improve pharmacokinetics and enhance tumor uptake of radioligands, including prostate-specific membrane antigen (PSMA) targeting agents. The goal of this study is to develop an optimal Evans blue-modified radiotherapeutic agent that could maximize the absolute tumor uptake and tumor absorbed dose thus the therapeutic efficacy to allow treatment of tumors even with moderate level of PSMA expression. METHODS: [177Lu]Lu-LNC1003 was synthesized based on PSMA-targeting agent and Evans blue. Binding affinity and PSMA targeting specificity were verified through cell uptake and competition binding assay in 22Rv1 tumor model that has moderate level of PSMA expression. SPECT/CT imaging and biodistribution studies in 22Rv1 tumor-bearing mice were performed to evaluate the preclinical pharmacokinetics. Radioligand therapy studies were conducted to systematically assess the therapeutic effect of [177Lu]Lu-LNC1003. RESULTS: LNC1003 showed high binding affinity (IC50 = 10.77 nM) to PSMA in vitro, which was comparable with that of PSMA-617 (IC50 = 27.49 nM) and EB-PSMA-617 (IC50 = 7.91 nM). SPECT imaging of [177Lu]Lu-LNC1003 demonstrated significantly improved tumor uptake and retention as compared with [177Lu]Lu-EB-PSMA and [177Lu]Lu-PSMA-617, making it suitable for prostate cancer therapy. Biodistribution studies further confirmed the remarkably higher tumor uptake of [177Lu]Lu-LNC1003 (138.87 ± 26.53%ID/g) over [177Lu]Lu-EB-PSMA-617 (29.89 ± 8.86%ID/g) and [177Lu]Lu-PSMA-617 (4.28 ± 0.25%ID/g) at 24 h post-injection. Targeted radioligand therapy results showed noteworthy inhibition of 22Rv1 tumor growth after administration of a single dose of 18.5 MBq [177Lu]Lu-LNC1003. There was no obvious antitumor effect after [177Lu]Lu-PSMA-617 treatment under the same condition. CONCLUSION: In this study, [177Lu]Lu-LNC1003 was successfully synthesized with high radiochemical purity and stability. High binding affinity and PSMA targeting specificity were identified in vitro and in vivo. With greatly enhanced tumor uptake and retention, [177Lu]Lu-LNC1003 has the potential to improve therapeutic efficacy using significantly lower dosages and less cycles of 177Lu that promises clinical translation to treat prostate cancer with various levels of PSMA expression.

NIR Light-Activated and RGD-Conjugated Ultrasmall Fe/PPy Nanopolymers for Enhanced Tumor Photothermal Ferrotherapy and MR Imaging.

Iron-based nanomaterials have shown great promise for tumor ferrotherapy in recent years. However, nanoparticle-induced ferroptosis has low therapeutic efficacy owing to unsatisfactory Fenton reaction activity in a typical tumor microenvironment. In this study, NIR light-activated Fe/PPy-RGD nanopolymers were developed to combine photothermal therapy and ferrotherapy and achieve enhanced antitumor activity. Importantly, Fe/PPy-RGD exhibited excellent therapeutic performance under NIR light activation both in vitro and in vivo. Under irradiation with NIR light, the heat generated by Fe/PPy-RGD not only induced a therapeutic photothermal effect but also enhanced the release of iron ions and the Fenton reaction by inducing ferroptosis. Additionally, by virtue of RGD conjugation and its ultrasmall size, Fe/PPy-RGD could effectively accumulate at tumor sites in living mice after systemic administration and could be monitored via MR imaging. Hence, this study provides a promising approach for integrating ferrotherapy with photothermal therapy to achieve enhanced tumor treatment.

Fe(II)-Targeted PET/19F MRI Dual-Modal Molecular Imaging Probe for Early Evaluation of Anticancer Drug-Induced Acute Kidney Injury.

Ferroptosis, an iron-dependent regulated cell death, has been emerging as an early mechanism in anticancer drug-induced acute kidney injury (AKI) that may benefit therapeutic intervention. However, the lack of molecular imaging methods for in vivo detection of ferroptosis restricts the early diagnosis of anticancer drug-induced AKI. Herein, we developed a PET/19F MRI dual-modal imaging probe for the monitoring of ferroptosis in AKI by chemically conjugating the Fe(II)-sensitive artemisinin (Art) motif and macrocyclic ligand 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) to the CF3-modified polyhedral oligomeric silsesquioxane (POSS) clusters, denoted as the PAD probe. The PAD probe could be converted into PA*D in the presence of Fe(II) ions and subsequently be intercepted by biological macromolecules nearby, thereby enhancing the retention effect in ferroptotic cells and tissues. After labeling with 68Ga isotopes, the 68Ga-labeled PAD probe in cisplatin (CDDP)-induced AKI mice displayed a significantly higher renal uptake level than that in normal mice. Moreover, the PAD probe with a precise chemical structure, relatively high 19F content, and single 19F resonance frequency allowed for interference-free and high-performance19F MRI that could detect the onset of CDDP-induced AKI at least 24 h earlier than the typical clinical/preclinical assays. Our study provides a robust dual-modal molecular imaging tool for the early diagnosis and mechanistic investigation of various ferroptosis-related diseases.

Highly Luminescent Nonclassical Binuclear Manganese(II) Complex Scintillators for Efficient X-ray Imaging.

Scintillators can be widely applied to the fields of radioactivity detection, space exploration, and medical diagnosis and have attracted great attention. Recently, manganese(II) complexes with high-efficiency phosphorescent emission are expected to be good candidates for new scintillator materials. Herein, we design and synthesize a series of novel nonclassical binuclear neutral manganese(II) complexes with unique coordination modes, in which the crystal structures of CP1 and CP2 contain both four-coordinated and six-coordinated manganese(II) centers and CP3 is formed as a binuclear five-coordinated dichloro-bridged dimer. The single crystals of CP1-CP3 exhibit excellent stability, which can be attributed to their nonionic structures. They all exhibit intense red emission under UV and X-ray irradiation. Among the three manganese(II) complexes, CP1 demonstrates the best luminescence efficiency and X-ray scintillation performance with a high photoluminescence quantum yield (PLQY) of 91.9%, a relative light yield of 21037 photons MeV-1, and a detection limit of 34.45 nGyair s-1. Moreover, X-ray imaging based on CP1 scintillator screen demonstrates a spatial resolution of nearly 6 lp mm-1. As far as we know, this is the first report about stable binuclear neutral manganese(II) complexes for X-ray imaging and opens a new avenue for exploring novel scintillator materials.

Specific Cellular Effects of Low Bortezomib Concentrations on Purified Cultures of Schwann Cells, Satellite Glial Cells, Macrophages, and Dorsal Root Ganglion Neurons.

Peripheral neuropathy is one of the major adverse effects that limit the clinical application of bortezomib (BTZ). However, the underlying mechanisms of BTZ-induced peripheral neuropathy (BIPN) remain elusive. To examine cell types potentially involved in the development of BIPN, we used four purified cultures of cells of the peripheral nervous system: Schwann cells (SCs), satellite glial cells (SGCs), macrophages, and dorsal root ganglion (DRG) neurons. Administration of a low BTZ concentration (5 nM; similar to concentrations in clinical use) caused dedifferentiation of cultured SCs, returning mature SCs to an immature state. In cultured SGCs, BTZ increased glial fibrillary acidic protein (GFAP) levels without inducing the release of inflammatory cytokines or chemokines. In macrophages, BTZ caused little inflammatory response. Finally, in DRG neurons, BTZ strongly suppressed the expression levels of sensor and transducer ion channels without affecting cell morphology. Taken together, low concentrations of BTZ can cause SC dedifferentiation (i.e., demyelination), increased GFAP level in SGC, and decreased expression levels of sensor and transducer ion channels in DRG neurons (i.e., numbness feeling). Thus, we have reported, for the first time, specific effects of BTZ on peripheral nervous system cells, thereby contributing to a better understanding of the initiating mechanism of BIPN.

Inhibitors of the Mechanistic Target of Rapamycin Can Ameliorate Bortezomib-Induced Peripheral Neuropathy.

Bortezomib, an anticancer drug for multiple myeloma and mantle cell lymphoma, causes severe adverse events and leads to peripheral neuropathy. The associated neuropathy limits the use of bortezomib and could lead to discontinuation of the treatment; therefore, effective intervention is crucial. In the present study, we statistically searched for a drug that could alleviate bortezomib-induced peripheral neuropathy using adverse event self-reports. We observed that specific inhibitors of the mechanistic target of rapamycin (mTOR) lowered the incidence of bortezomib-induced peripheral neuropathy. These findings were experimentally validated in mice, which exhibited long-lasting mechanical hypersensitivity after repeated bortezomib treatment. This effect was inhibited for hours after a systemic injection with rapamycin or everolimus in a dose-dependent manner. Bortezomib-induced allodynia was accompanied by the activation of spinal astrocytes, and intrathecal injection of mTOR inhibitors or an inhibitor of ribosomal protein S6 kinase 1, a downstream target of mTOR, exhibited considerable analgesic effects in a dose-dependent manner. These results suggest that mTOR inhibitors, which are readily available to patients prescribed bortezomib, are one of the most effective therapeutics for bortezomib-induced peripheral neuropathy.

Stable Loading of TiO2 Catalysts on the Surface of Metal Substrate for Enhanced Photocatalytic Toluene Oxidation.

To promote the practical application of TiO2 in photocatalytic toluene oxidation, the honeycomb aluminum plates were selected as the metal substrate for the loading of TiO2 powder. Surface-etching treatment was performed and titanium tetrachloride was selected as the binder to strengthen the loading stability. The loading stability and photocatalytic activity of the monolithic catalyst were further investigated, and the optimal surface treatment scheme (acid etching with 15.0 wt.% HNO3 solution for 15 min impregnation) was proposed. Therein, the optimal monolithic catalyst could achieve the loading efficiency of 42.4% and toluene degradation efficiencies of 76.2%. The mechanism for the stable loading of TiO2 was revealed by experiment and DFT calculation. The high surface roughness of metal substrate and the strong chemisorption between TiO2 and TiCl4 accounted for the high loading efficiency and photocatalytic activity. This work provides the pioneering exploration for the practical application of TiO2 catalysts loaded on the surface of metal substrate for VOCs removal, which is of significance for the large-scaled application of photocatalytic technology.

Enhanced Catalytic Soot Oxidation over Co-Based Metal Oxides: Effects of Transition Metal Doping.

A series of Co-M (M = Fe, Cr, and Mn) catalysts were synthesized by the sol-gel method for soot oxidation in a loose contact mode. The Co-Fe catalyst exhibited the best catalytic activity among the tested samples, with the characteristic temperatures (T10, T50, and T90) of 470 °C, 557 °C, and 602 °C, respectively, which were 57 °C, 51 °C, and 51 °C lower than those of the CoOx catalyst. Catalyst characterizations of N2 adsorption-desorption, X-ray diffraction (XRD), X-ray photo-electron spectrometry (XPS), and the temperature programmed desorption of O2 (O2-TPD) were performed to gain insights into the relationships between the activity of catalytic soot oxidation and the catalyst properties. The content of Co2+ (68.6%) increased due to the interactions between Co and Fe, while the redox properties and the relative concentration of surface oxygen adsorption (51.7%) were all improved, which could significantly boost the activity of catalytic soot oxidation. The effects of NO and contact mode on soot oxidation were investigated over the Co-Fe catalyst. The addition of 1000 ppm of NO led to significant reductions in T10, T50, and T90 by 92 °C, 106 °C, and 104 °C, respectively, compared to the case without the NO addition. In the tight contact mode, the soot oxidation was accelerated over the Co-Fe catalyst, resulting in 46 °C, 50 °C, and 50 °C reductions in T10, T50, and T90 compared to the loose contact mode. The comparison between real soot and model Printex-U showed that the T50 value of real soot (455 °C) was 102 °C lower than the model Printex-U soot.