Waste Plastic-Supported Pd Single-Atom Catalyst for Hydrogenation.

As worldwide plastic pollution continues to rise, innovative ideas for effective reuse and recycling of waste plastic are needed. Single-atom catalysts (SACs), which are known for their high activity and selectivity, present unique advantages in facilitating plastic degradation and conversion. Waste plastic can be used as a support or raw material to create SACs, which reduces waste generation while simultaneously utilizing waste as a resource. This work successfully utilized waste plastic polyurethane (PU) as a support, through a unique Rapid Thermal Processing Reactor (RTPR) to synthesize an efficient Pd1/PU SACs. At 25 °C and 0.5 MPa H2, Pd1/PU displayed outstanding activity and selectivity in the hydrogenation of styrene, as well as remarkable stability. Pd1/PU performed well in hydrogenating a variety of common substrates. These findings highlight the great potential of SACs in plastic waste reuse and recycling, offering intriguing solutions to the global plastic pollution problem.

WO3/BiOBr S-Scheme Heterojunction Photocatalyst for Enhanced Photocatalytic CO2 Reduction.

The photocatalytic CO2 reduction strategy driven by visible light is a practical way to solve the energy crisis. However, limited by the fast recombination of photogenerated electrons and holes in photocatalysts, photocatalytic efficiency is still low. Herein, a WO3/BiOBr S-scheme heterojunction was formed by combining WO3 with BiOBr, which facilitated the transfer and separation of photoinduced electrons and holes and enhanced the photocatalytic CO2 reaction. The optimized WO3/BiOBr heterostructures exhibited best activity for photocatalytic CO2 reduction without any sacrificial reagents, and the CO yield reached 17.14 µmol g-1 after reaction for 4 h, which was 1.56 times greater than that of BiOBr. The photocatalytic stability of WO3/BiOBr was also improved.

Facet-dependent synthesis of H2O2 from H2 and O2 over single Pt atom-modified Pd nanocrystal catalysts.

Hydrogen peroxide (H2O2) is one of the most valuable clean energy sources with a rapidly growing requirement in industry and daily life. The direct synthesis of H2O2 from hydrogen and oxygen is considered to be an economical and environmentally friendly manufacturing route to replace the traditional anthraquinone method, although it remains a formidable challenge owing to low H2O2 selectivity and production. Here, we report a catalyst consisting of Pd(111) nanocrystals on TiO2 modified with single Pt atoms (Pt1Pd(111)/TiO2), which displays outstanding reactivity, producing 1921.3 µmol of H2O2, a H2 conversion of 62.2% and H2O2 selectivity of 80.3% over 30 min. Kinetic and isotope experiments confirm that the extraordinary catalytic properties are due to stronger H2 activation (the rate-determining step). DFT calculations confirm that Pt1Pd(111) exhibits lower energy barriers for H2 dissociation and two-step O2 hydrogenation, but higher energy barriers for side reactions than Pt1Pd(100), demonstrating clear facet dependence and resulting in greater selectivity and amount of H2O2 produced.

Cluster-CAM: Cluster-weighted visual interpretation of CNNs' decision in image classification.

Despite the tremendous success of convolutional neural networks (CNNs) in computer vision, the mechanism of CNNs still lacks clear interpretation. Currently, class activation mapping (CAM), a famous visualization technique to interpret CNN's decision, has drawn increasing attention. Gradient-based CAMs are efficient, while the performance is heavily affected by gradient vanishing and exploding. In contrast, gradient-free CAMs can avoid computing gradients to produce more understandable results. However, they are quite time-consuming because hundreds of forward interference per image are required. In this paper, we proposed Cluster-CAM, an effective and efficient gradient-free CNN interpretation algorithm. Cluster-CAM can significantly reduce the times of forward propagation by splitting the feature maps into clusters. Furthermore, we propose an artful strategy to forge a cognition-base map and cognition-scissors from clustered feature maps. The final salience heatmap will be produced by merging the above cognition maps. Qualitative results conspicuously show that Cluster-CAM can produce heatmaps where the highlighted regions match the human's cognition more precisely than existing CAMs. The quantitative evaluation further demonstrates the superiority of Cluster-CAM in both effectiveness and efficiency.

Antioxidant Properties of Platycladus orientalis Flavonoids for Treating UV-Induced Damage in Androgenetic Alopecia Hair.

BACKGROUND: Androgenetic alopecia (AGA) causes thinning hair, but poor hair quality in balding areas and damage from UV radiation have been overlooked. Plant extracts like Platycladus orientalis flavonoids (POFs) may improve hair quality in AGA. This study examines POFs' effectiveness in treating AGA-affected hair and repairing UV-induced damage. METHODS: Hair samples were analyzed using scanning electron microscopy (SEM) to examine surface characteristics, electron paramagnetic resonance (EPR) spectroscopy to measure free radicals in the hair, and spectrophotometry to assess changes in hair properties. RESULTS: POFs effectively removed hydroxyl radicals from keratinocytes and had antioxidant properties. They also reduced UV-induced damage to AGA hair by mitigating the production of melanin free radicals. Following POF treatment, the reduction in peroxidized lipid loss in AGA hair was notable at 59.72%, thereby effectively delaying the progression of hair color change. Moreover, protein loss decreased by 191.1 µ/g and tryptophan loss by 15.03%, ultimately enhancing hair's tensile strength. CONCLUSION: compared to healthy hair, hair damaged by AGA shows more pronounced signs of damage when exposed to UV radiation. POFs help protect balding hair by reducing oxidative damage and slowing down melanin degradation.

One-dimensional Ga2O3-Al2O3 nanofibers with unsaturated coordination Ga: Catalytic dehydrogenation of propane under CO2 atmosphere with excellent stability.

The pressing demand for propylene has spurred intensive research on the catalytic dehydrogenation of propane to produce propylene. Gallium-based catalysts are regarded as highly promising due to their exceptional dehydrogenation activity in the presence of CO2. However, the inherent coking issue associated with high temperature reactions poses a constraint on the stability development of this process. In this study, we employed the electrospinning method to prepare a range of Ga2O3-Al2O3 mixed oxide one-dimensional nanofiber catalysts with varying molar ratios for CO2 oxidative dehydrogenation of propane (CO2-OPDH). The propane conversion was up to 48.4 % and the propylene selectivity was high as 96.8 % at 500 °C, the ratio of propane to carbon dioxide is 1:2. After 100 h of reaction, the catalyst still maintains approximately 10 % conversion and exhibits a propylene selectivity of around 98 %. The electrospinning method produces one-dimensional nanostructures with a larger specific surface area, unique multi-stage pore structure and low-coordinated Ga3+, which enhances mass transfer and accelerates reaction intermediates. This results in less coking and improved catalyst stability. The high activity of the catalyst is attributed to an abundance of low-coordinated Ga3+ ions associated with weak/medium-strong Lewis acid centers. In situ infrared analysis reveals that the reaction mechanism involves a two-step dehydrogenation via propane isocleavage, with the second dehydrogenation of Ga-OR at the metal-oxygen bond being the decisive speed step.

Machine learning models for predicting thermal desorption remediation of soils contaminated with polycyclic aromatic hydrocarbons.

Among various remediation methods for organic-contaminated soil, thermal desorption stands out due to its broad treatment range and high efficiency. Nonetheless, analyzing the contribution of factors in complex soil remediation systems and deducing the results under multiple conditions are challenging, given the complexities arising from diverse soil properties, heating conditions, and contaminant types. Machine learning (ML) methods serve as a powerful analytical tool that can extract meaningful insights from datasets and reveal hidden relationships. Due to insufficient research on soil thermal desorption for remediation of organic sites using ML methods, this study took organic pollutants represented by polycyclic aromatic hydrocarbons (PAHs) as the research object and sorted out a comprehensive data set containing >700 data points on the thermal desorption of soil contaminated with PAHs from published literature. Several ML models, including artificial neural network (ANN), random forest (RF), and support vector regression (SVR), were applied. Model optimization and regression fitting centered on soil remediation efficiency, with feature importance analysis conducted on soil and contaminant properties and heating conditions. This approach enabled the quantitative evaluation and prediction of thermal desorption remediation effects on soil contaminated with PAHs. Results indicated that ML models, particularly the RF model (R2 = 0.90), exhibited high accuracy in predicting remediation efficiency. The hierarchical significance of the features within the RF model is elucidated as follows: heating conditions account for 52 %, contaminant properties for 28 %, and soil properties for 20 % of the model's predictive power. A comprehensive analysis suggests that practical applications should emphasize heating conditions for efficient soil remediation. This research provides a crucial reference for optimizing and implementing thermal desorption in the quest for more efficient and reliable soil remediation strategies.

TLR3 activation enhances abscopal effect of radiotherapy in HCC by promoting tumor ferroptosis.

Radiotherapy (RT) has been reported to induce abscopal effect in advanced hepatocellular carcinoma (HCC), but such phenomenon was only observed in sporadic cases. Here, we demonstrated that subcutaneous administration of Toll-like receptor 3 (TLR3) agonist poly(I:C) could strengthen the abscopal effect during RT through activating tumor cell ferroptosis signals in bilateral HCC subcutaneous tumor mouse models, which could be significantly abolished by TLR3 knock-out or ferroptosis inhibitor ferrostatin-1. Moreover, poly(I:C) could promote the presentation of tumor neoantigens by dendritic cells to enhance the recruitment of activated CD8+ T cells into distant tumor tissues for inducing tumor cell ferroptosis during RT treatment. Finally, the safety and feasibility of combining poly(I:C) with RT for treating advanced HCC patients were further verified in a prospective clinical trial. Thus, enhancing TLR3 signaling activation during RT could provide a novel strategy for strengthening abscopal effect to improve the clinical benefits of advanced HCC patients.

ß-Nicotinamide Mononucleotide Promotes Cell Proliferation and Hair Growth by Reducing Oxidative Stress.

ß-Nicotinamide mononucleotide (NMN) has shown promising effects on intestinal health, and it is extensively applied as an anti-aging and Alzheimer's disease therapeutic, due to its medicinal properties. The effects of NMN on the growth of mouse hair were observed after hair removal. The results indicated that NMN can reverse the state of hair follicle atrophy, hair thinning, and hair sparsity induced by dihydrotestosterone (DHT), compared to that of minoxidil. In addition, the action mechanisms of NMN promoting hair growth in cultured human dermal papilla cells (HDPCs) treated with DHT were investigated in detail. The incubation of HDPCs with DHT led to a decrease in cell viability and the release of inflammatory mediators, including interleukin-6 (IL-6), interleukin-1Beta (IL-1ß) and tumor necrosis factor Alpha (TNF-α). It was found that NMN can significantly lower the release of inflammatory factors induced by DHT in HDPCs. HDPCs cells are protected from oxidative stress damage by NMN, which inhibits the NF-κB p65 inflammatory signaling pathway. Moreover, the levels of androgen receptor (AR), dickkopf-1 (DKK-1), and ß-catenin in the HDPCs were assessed using PCR, indicating that NMN can significantly enhance the expression of VEGF, reduced IL-6 levels and suppress the expression of AR and DKK-1, and notably increase ß-catenin expression in DHT-induced HDPCs.

Bimetallic CoCu-modified Pt species in S-1 zeolite with enhanced stability for propane dehydrogenation.

Propane dehydrogenation (PDH) has been an outstanding technique with a bright prospect, which can meet the growing global demand for propylene. However, undesired side reactions result in the deactivation of the Pt-based catalysts, which contribute to the insufficient lifetime of the catalysts. Herein, we describe a novel catalyst by encapsulating bimetallic CoCu-modified Pt species in S-1 zeolite for efficient dehydrogenation of propane, which synergizes the confinement of zeolites and the geometric and electronic effects on Pt species for enhancing the catalyst stability. The introduction of bimetallic additives efficiently promotes the dispersion of platinum and the electron transfer between Pt species and the additives, which greatly prolongs the lifetime of the catalysts. Particularly, no obvious deactivation is observed on 0.2Pt0.3Co0.5CuK@S-1 after 93 h on stream with a weight hourly space velocity (WHSV) of 5.4 h-1, revealing an ultralow deactivation constant of 0.0011 h-1 (t = 909 h). The formation rate of propylene still maintains at a high value of 407 mol gPt-1 h-1 (WHSV = 21.6 h-1) at 580 ℃ even after on pure propane stream for 42 h. The catalyst with the bimetallic CoCu-modified Pt species in S-1 zeolite reveals ultra-high activity and stability for PDH, which is ascribed to the highly dispersed Pt species and the stabilization effect of bimetallic additives on Pt species.

Advances in ultrasonic treatment of oily sludge: mechanisms, industrial applications, and integration with combined treatment technologies.

In the petroleum sector, the generation of oily sludge is an unavoidable byproduct, necessitating the development of efficient treatment strategies for both economic gain and the mitigation of negative environmental impacts. The intricate composition of oily sludge poses a formidable challenge, as existing treatment methodologies frequently fall short of achieving baseline disposal criteria. The processes of demulsification and dehydration are integral to diminishing the oil content and reclaiming valuable crude oil, thereby playing a critical role in the management of oily sludge. Among the myriad of treatment solutions, ultrasonic technology has emerged as a particularly effective physical method, celebrated for its diverse applications and lack of resultant secondary pollution. This comprehensive review delves into the underlying mechanisms and recent progress in the ultrasonic treatment of oily sludge, with a specific focus on its industrial implementations within China. Both isolated ultrasonic treatment and its combination with other technological approaches have proven successful in addressing oily sludge challenges. The adoption of industrial-scale systems that amalgamate ultrasound with multi-technological processes has shown marked enhancements in treatment efficacy. The fusion of ultrasonic technology with other cutting-edge methods holds considerable potential across a spectrum of applications. To fulfill the goals of resource recovery, reduction, and neutralization in oily sludge management, the industrial adoption and adept application of a variety of treatment technologies are imperative.

Boosting the Catalase-Like Activity of SAzymes via Facile Tuning of the Distances between Neighboring Atoms in Single-Iron Sites.

A nanozyme with neighboring single-iron sites (Fe2 -SAzyme) was introduced as a bioinspired catalase mimic, featuring excellent activity under varied conditions, twice as high as that of random Fe1 -SAzyme and ultrahigh H2 O2 affinity as that of bioenzymes. Surprisingly, the interatomic spacing tuning between adjacent iron sites also suppressed the competitive peroxidase pathway, remarkably increasing the catalase/peroxidase selectivity up to ~6 times compared to Fe1 -SAzyme. This dramatically switched the catalytic activity of Fe-SAzymes from generating (i.e. Fe1 -SAzymes, preferably mimicking peroxidase) to scavenging ROS (i.e. Fe2 -SAzymes, dominantly mimicking catalase). Theoretical and experimental investigations suggested that the pairwise single-iron sites may serve as a robust molecular tweezer to efficiently trap and decompose H2 O2 into O2 , via cooperative hydrogen-bonding induced end-bridge adsorption. The versatile mechano-assisted in situ MOF capsulation strategy enabled facile access to neighboring M2 -SAzyme (M=Fe, Ir, Pt), even up to a 1000 grams scale, but with no obvious scale-up effect for both structures and performances.

Novel synergistically effects of palladium-iron bimetal and manganese carbonate carrier for catalytic oxidation of formaldehyde at room temperature.

The elimination of formaldehyde at room temperature holds immense potential for various applications, and the incorporation of a catalyst rich in surface hydroxyl groups and oxygen significantly enhances its catalytic activity towards formaldehyde oxidation. By employing a coprecipitation method, we successfully achieved a palladium domain confined within the manganese carbonate lattice and doped with iron. This synergistic effect between highly dispersed palladium and iron greatly amplifies the concentration of surface hydroxyl groups and oxygen on the catalyst, thereby enabling complete oxidation of formaldehyde at ambient conditions. The proposed method facilitates the formation of domain-limited palladium within the MnCO3 lattice, thereby enhancing the dispersion of palladium and facilitating its partial incorporation into the MnCO3 lattice. Consequently, this approach promotes increased exposure of active sites and enhances the catalyst's capacity for oxygen activation. The co-doping of iron effectively splits the doping sites of palladium to further enhance its dispersion, while simultaneously modifying the electronic modification of the catalyst to alter formaldehyde's adsorption strength on it. Manganese carbonate exhibits superior adsorption capability for activated surface hydroxyl groups due to the presence of carbonate. In situ infrared testing revealed that dioxymethylene and formate are primary products resulting from catalytic oxidation of formaldehyde, with catalyst surface oxygen and hydroxyl groups playing a crucial role in intermediate product decomposition and oxidation. This study provides novel insights for designing palladium-based catalysts.

Correction: Tubular metal organic frameworks from the curvature of 2D-honeycombed metal coordination.

Correction for 'Tubular metal organic frameworks from the curvature of 2D-honeycombed metal coordination' by Junhui Bao et al., Dalton Trans., 2020, 49, 2403-2406, https://doi.org/10.1039/C9DT04668B.

Temperature-Sensitive Aerogel Using Bagasse Carboxylated Cellulose Nanocrystals/N-Isopropyl Acrylamide for Controlled Release of Pesticides.

Temperature-sensitive carboxylated cellulose nanocrystals/N-isopropyl acrylamide aerogels (CCNC-NIPAMs) were developed as novel pesticide-controlled release formulas. Ammonium persulfate (APS) one-step oxidation was used to prepare bagasse-based CCNCs, and then the monomer N-isopropyl acrylamide (NIPAM) was successfully introduced and constructed into the temperature-sensitive CCNC-NIPAMs through polymerization. The results of the zeta potential measurement and Fourier infrared transform spectrum (FTIR) show that the average particle size of the CCNCs was 120.9 nm, the average surface potential of the CCNCs was -34.8 mV, and the crystallinity was 62.8%. The primary hydroxyl group on the surface of the CCNCs was replaced by the carboxyl group during oxidation. The morphology and structure of CCNC-NIPAMs were characterized via electron microscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), compression performance, porosity analysis, and thermogravimetric (TG) analysis. The results demonstrate that CCNC-NIPAM has a high porosity and low density, as well as good thermal stability, which is conducive to loading and releasing pesticides. In the swelling, drug loading, and controlled release process, the CCNC-NIPAM exhibited significant temperature sensitivity. Under the same NIPAM reaction amount, the equilibrium swelling rate of the CCNC-NIPAM first increased and then decreased with increasing temperature, and the cumulative drug release ratio of the CCNC-NIPAM at 39 °C was significantly higher than that at 25 °C. The loading efficiency of the CCNC-NIPAM on the model drug thiamethoxam (TXM) was up to 23 wt%, and the first-order model and Korsmyer-Peppas model could be well-fitted in the drug release curves. The study provides a new method for the effective utilization of biomass and pesticides.

Phosphorus-Doped Hollow Tubular g-C3N4 for Enhanced Photocatalytic CO2 Reduction.

Photocatalytic CO2 reduction is a tactic for solving the environmental pollution caused by greenhouse gases. Herein, NH4H2PO4 was added as a phosphorus source in the process of the hydrothermal treatment of melamine for the first time, and phosphorus-doped hollow tubular g-C3N4 (x-P-HCN) was fabricated and used for photocatalytic CO2 reduction. Here, 1.0-P-HCN exhibited the largest CO production rate of 9.00 µmol·g-1·h-1, which was 10.22 times higher than that of bulk g-C3N4. After doping with phosphorus, the light absorption range, the CO2 adsorption capacity, and the specific surface area of the 1.0-P-HCN sample were greatly improved. In addition, the separation of photogenerated electron-hole pairs was enhanced. Furthermore, the phosphorus-doped g-C3N4 effectively activated the CO2 adsorbed on the surface of phosphorus-doped g-C3N4 photocatalysts, which greatly enhanced the CO production rate of photocatalytic CO2 reduction over that of g-C3N4.

Carbonized polymer dots modified ZnIn2S4 microspheres for visible-light-driven hydrogen evolution promotion performance.

To effectively separate electron-hole pairs produced by light, a heterojunction arrangement can be employed, thereby improving photocatalytic efficiency. In this study, a simple hydrothermal process is used to manufacture carbonized polymer dots/ZnIn2S4 (CPDs/ZIS) heterostructure, which enhances the light absorption and charge carrier lifetime in comparison to bare ZnIn2S4 (ZIS). Upon irradiation with visible light, the 3-CPDs/ZIS composite generates hydrogen at a rate of 133 µmol g-1 h-1, which is 8.9 times faster than that of pure ZIS. The addition of CPDs can increase the range of light that can be absorbed, extend the service life of the optical charge, increase the specific surface area, and promote charge separation and transmission, which could effectively accelerate the photocatalytic reduction reaction. The presence of CPDs results in the introduction of multiple transition energy states and a decrease in the H* adsorption free energy, which enhances the hydrogen evolution activity according to the theoretical calculation findings of density functional theory (DFT) and Gibbs free energy of the hydrogen evolution process. Combining theoretical calculations and experimental results, a direct Z-type heterojunction mechanism is proposed for the hydrogen evolution promotion effectiveness of CPDs/ZIS under visible light.

One-step ethylene purification from ternary mixtures by an ultramicroporous material with synergistic binding centers.

Developing advanced porous materials with industrial potential to separate multicomponent gas mixtures that are structurally similar is a crucial but challenging task. Here, we report the efficient one-step separation of ethylene (C2H4) from acetylene (C2H2) and carbon dioxide (CO2) using an ultramicroporous metal-organic framework UTSA-16. The synergistic effect of the polarized carboxyl groups and coordinated water molecules in its pore channel enables the material to have high uptakes for C2H2 and CO2 due to electrostatic potential matching, as well as excellent separation selectivity against C2H4. Breakthrough experiments suggest that UTSA-16 can efficiently separate 99.9% pure C2H4 from ternary mixtures with a high productivity of 403 L kg-1. Moreover, the preparation cost of UTSA-16 is significantly lower than other related adsorbents by 40-2000 times, indicating its unique potential for industrial applications.

Analytical interpretation of the gap of CNN's cognition between SAR and optical target recognition.

Synthetic aperture radar (SAR) automatic target recognition (ATR) is a crucial technique utilized in various scenarios of geoscience and remote sensing. Despite the remarkable success of convolutional neural networks (CNNs) in optical vision tasks, the application of CNNs in SAR ATR is still a challenging area due to the significant differences in the imaging mechanisms of SAR and optical images. This paper analytically addresses the cognitive gap of CNNs between optical and SAR images by leveraging multi-order interactions to measure their representation capacity. Furthermore, we propose a subjective evaluation strategy to compare human interactions with those of CNNs. Our findings reveal that CNNs operate differently for optical and SAR images. Specifically, for SAR images, CNNs' representation capacity is comparable to that of humans, as they can encode intermediate interactions better than simple and complex ones. In contrast, for optical images, CNNs excel at encoding simple and complex interactions, but not intermediate interactions.