First-Row Transition Metals for Catalyzing Oxygen Redox.

Rechargeable zinc-air batteries are widely recognized as a highly promising technology for energy conversion and storage, offering a cost-effective and viable alternative to commercial lithium-ion batteries due to their unique advantages. However, the practical application and commercialization of zinc-air batteries are hindered by the sluggish kinetics of the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Recently, extensive research has focused on the potential of first-row transition metals (Mn, Fe, Co, Ni, and Cu) as promising alternatives to noble metals in bifunctional ORR/OER electrocatalysts, leveraging their high-efficiency electrocatalytic activity and excellent durability. This review provides a comprehensive summary of the recent advancements in the mechanisms of ORR/OER, the performance of bifunctional electrocatalysts, and the preparation strategies employed for electrocatalysts based on first-row transition metals in alkaline media for zinc-air batteries. The paper concludes by proposing several challenges and highlighting emerging research trends for the future development of bifunctional electrocatalysts based on first-row transition metals.

Multi-Pleated Alkalized Ti3 C2 Tx MXene-Based Sandwich-Like Structure Composite Nanofibers for High-Performance Sodium/Lithium Storage.

The volume expansion of CoFe2 O4 anode poses a significant challenge in the commercial application of lithium/sodium-ion batteries (LIBs/SIBs). However, metal-organic-frameworks (MOF) offer superior construction of heterostructures with refined interfacial interactions and lower ion diffusion barriers in Li/Na storage. In this study, the CoFe2 O4 @carbon nanofibers derived from MOF are produced through electrospinning, in situ growth followed by calcination, which are then confined within an MXene-confined MOF-derived porous CoFe2 O4 @carbon composite architecture under alkali treatment. The CoFe2 O4 nanofibers anchor on the alkalized MXene that is decorated with the NaOH solution to form a multi-pleated structure. The sandwich-like structure of the composite effectively alleviates the volume expansion and shortens the Li/Na-ion diffusion path, which displays high capacity and outstanding rate performance as anode materials for LIBs/SIBs. As a consequence, the obtained CoFe2 O4 @carbon@alkalized MXene composite anode shows satisfied rate performance at current density of 10 A g-1 for LIBs (318 mAh·g-1 ) and 5 A g-1 for SIBs (149 mAh g-1 ). The excellent cycling performance is further demonstrated at a high current density, where it maintains a discharge capacity of 807 mAh g-1 at 2 A g-1 after 400 cycles for LIBs and 130 mAh g-1 at 1 A g-1 even after 1000 cycles for SIBs.

Effect of steric hindrance and number of substituents on the transfer and interface properties of Y-shaped hole-transporting materials for perovskite solar cells.

Alkyl sulfoxide groups were introduced into the branch chain terminals of a hole-transporting material (HTM) Z34 with different numbers and positions to design four new Y-shaped HTMs: ZT1, ZT2, ZT3 and ZT4. The effects of steric hindrance and number of substituents on the transfer and interface properties of the Y-shaped HTMs were investigated theoretically. Calculations reveal that the introduction of alkyl sulfoxide increases the distribution of intramolecular holes and orbital overlap between the HOMOs of the dimers. The electronic coupling was greatly improved owing to the increased distribution of holes and orbital overlap. ZT1 shows small steric hindrance when one alkyl sulfoxide is introduced into the top branch chain, which leads to translation π-π stacking. ZT2 and ZT4 show slightly greater steric hindrance when two or four alkyl sulfoxide groups are introduced into the side branch chains, which leads to face-to-face stacking. While ZT3 shows large steric hindrance when three alkyl sulfoxide groups are introduced into the top and side branch chains, which causes head-to-head stacking. With the increase in number of alkyl sulfoxide groups, the steric hindrance of the molecule increases and the hole mobility decreases. ZT1 achieves the highest hole mobility (2.63 × 10-2 m2 V-1 s-1) that is two orders of magnitude higher than that of Z34 (1.36 × 10-4 m2 V-1 s-1) owing to the optimal balance between the number of alkyl sulfoxide groups and steric hindrance. The HTM/CH3NH3PbI3 adsorbed system was also simulated to characterize the interface properties. Enhanced interface interaction was achieved in the HTM/perovskite systems of ZT2 and ZT3. The orbital distribution of the HTM/perovskite cluster indicates that the new HTMs can promote hole migration and prevent internal electron-hole recombination. The present work not only evaluates the reliable relationship between the structure and properties of new HTMs, but also provides a valuable design strategy for efficient Y-shaped HTMs.

Boosting electrochemical CO2 reduction via valence state and oxygen vacancy controllable Bi-Sn/CeO2 nanorod.

Electrocatalytic CO2 reduction reaction (CO2RR) to produce formate has been recognized as one of the most efficient strategies to convert CO2 to energy-rich products and store renewable energy compared with other methods such as biological reduction, thermal catalytic reduction, and photocatalytic reduction. Developing an efficient catalyst is crucial to enhance the formate Faradaic efficiency (FEformate) and retard the competing H2 evolution reaction. The combination of Sn and Bi has been demonstrated to be effective in inhibiting the evolution of H2 and the generation of CO, promoting the formation of formate. Herein, we design Bi- and Sn-anchored CeO2 nanorods catalysts with the valence state and oxygen vacancy (Vo) concentration controllable for CO2RR by reduction treatment at different environments. The m-Bi1Sn2Ox/CeO2 with moderate H2 composition reduction and suitable Sn/Bi molar ratio achieves a remarkable FEformate of 87.7% at -1.18 V vs. RHE compared with other catalysts. Additionally, the selectivity of formate was maintained over 20 h with an outstanding FEformate of above 80% in 0.5 M KHCO3 electrolyte. The outstanding CO2RR performance was attributed to the highest surface Sn2+ concentration which improves the formate selectivity. Further, the electron delocalization effect between Bi, Sn, and CeO2 tunes electronic structure and Vo concentration, promoting the CO2 adsorption and activation as well as facilitating the formation of key intermediates HCOO* as evidenced by the in-situ Attenuated Total Reflectance-Fourier Transform Infrared measurements and Density Functional Theory calculations. This work provides an interesting measure for the rational design of efficient CO2RR catalysts via valence state and Vo concentration control.

The electronic structure and interfacial contact with metallic borophene of monolayer ScSX (X = I, Br, and Cl).

Two-dimensional (2D) semiconductors with excellent electronic and optical properties provide a great prospect for the fundamental research and application for the next-generation devices. Exploring the contact properties between 2D semiconductors and metal electrodes for improving the performance of nanodevices is of utmost importance. Motivated by the successful synthesis of bulk ScSI experimentally in a recent work [A. M. Ferrenti, M. A. Siegler, S. Gao, N. Ng and T. M. McQueen, Chem. Mater., 2022, 34, 12, 5443-5451], here we systematically investigate the intrinsic structural, electronic and optical properties of the novel monolayer ScSX (X = I, Br, and Cl) and their interfacial contact properties with the metal electrode of borophene using first-principles calculations. Interestingly, halogen X atoms with different electronegativities not only influence the intrinsic properties of monolayer ScSX, but also affect the interlayer coupling between monolayer ScSX and metallic borophene. The ScSI/borophene heterostructure forms a p-type Schottky contact, while both ScSBr/borophene and ScSCl/borophene heterostructures form a n-type Schottky contact. Moreover, our calculations demonstrate that strain engineering and applying an external electric field are effective strategies to regulate the Schottky barrier and contact types at the interface of ScSX/borophene. These findings provide a very promising path for designing tunable Schottky nanodevices with high-performance based on monolayer ScSX.

Wet-etched asymmetric spherical nanoparticles with controllable pit structures and application in non-aqueous foams.

The structure of colloidal particles is one of the factors that significantly affect their properties. Asymmetrical spherical particles with pit structures were prepared by using NH4F to perform wet chemical etching on the designated positions of the partially masked particles. The depth and effectiveness of the pits were adjusted by varying the etching time. By changing the properties of the oil mixture, the oil repellency and foaming ability of the etched particles were characterized and compared. By controlling the wet etching time, the effective pit structures were etched on the particles. Within 10 d of being etched, the particles with pit geometry showed better foam properties than the original unetched particles. The pit structure on the particles improves the oil repellency of the particles in a series of oil mixtures with relatively lower surface tension. No significant difference was observed between the under-etched (18 h) particles and the non-etched particles. The ineffective geometry of the over-etched (15 d) particles results in insufficient robustness of the Cassie-Baxter state of the particles and reduces the volume of the generated foam.

Correction to: CD103-positive CSC exosome promotes EMT of clear cell renal cell carcinoma: role of remote MiR-19b-3p.

An amendment to this paper has been published and can be accessed via the original article.

CD103-positive CSC exosome promotes EMT of clear cell renal cell carcinoma: role of remote MiR-19b-3p.

BACKGROUND: Clear cell renal cell carcinoma (CCRCC) is characterized by a highly metastatic potential. The stromal communication between stem cells and cancer cells critically influences metastatic dissemination of cancer cells. METHODS: The effect of exosomes isolated from cancer stem cells (CSCs) of CCRCC patients on the progress of epithelial-mesenchymal transition (EMT) and lung metastasis of CCRCC cells were examined. RESULTS: CSCs exosomes promoted proliferation of CCRCC cells and accelerated the progress of EMT. Bioactive miR-19b-3p transmitted to cancer cells by CSC exosomes induced EMT via repressing the expression of PTEN. CSCs exosomes derived from CCRCC patients with lung metastasis produced the strongest promoting effect on EMT. Notably, CD103+ CSC exosomes were enriched in tumor cells and in lung as well, highlighting the organotropism conferred by CD103. In addition, CD103+ exosomes were increased in blood samples from CCRCC patients with lung metastasis. CONCLUSIONS: CSC exosomes transported miR-19b-3p into CCRCC cells and initiated EMT promoting metastasis. CD103+ acted to guide CSC exosomes to target cancer cells and organs, conferring the higher metastatic capacity of CCRCC to lungs, suggesting CD103+ exosomes as a potential metastatic diagnostic biomarker. ᅟ.

Cabin air dynamics: Unraveling the patterns and drivers of volatile organic compound distribution in vehicles.

Volatile organic compounds (VOCs) are ubiquitous in vehicle cabin environments, which can significantly impact the health of drivers and passengers, whereas quick and intelligent prediction methods are lacking. In this study, we firstly analyzed the variations of environmental parameters, VOC levels and potential sources inside a new car during 7 summer workdays, indicating that formaldehyde had the highest concentration and about one third of the measurements exceeded the standard limit for in-cabin air quality. Feature importance analysis reveals that the most important factor affecting in-cabin VOC emission behaviors is the material surface temperature rather than the air temperature. By introducing the attention mechanism and ensemble strategy, we present an LSTM-A-E deep learning model to predict the concentrations of 12 observed typical VOCs, together with other five deep learning models for comparison. By comparing the prediction-observation discrepancies and five evaluation metrics, the LSTM-A-E model demonstrates better performance, which is more consistent with field measurements. Extension of the developed model for predicting the 10-day VOC concentrations in a realistic residence further illustrates its excellent environmental adaptation. This study probes the not-well-explored in-cabin VOC dynamics via observation and deep learning approaches, facilitating rapid prediction and exposure assessment of VOCs in the vehicle micro-environment.

Flexible Self-Supporting MOF-Based Bean Pod Cube Hollow Nanofibers for Ultralong Cycling and High Rate Na Storage.

Sodium-ion batteries (SIBs) have garnered significant attention due to their potential as an emerging energy storage solution. Tin sulfide (SnS) has emerged as a promising anode material for SIBs due to its impressive theoretical specific capacity of 1022 mA h g-1 and excellent electrical conductivity. However, its practical application has been hindered by issues such as large volume expansion, which adversely affects cycling stability and rate performance during the charge/discharge processes. In this study, a novel approach to address these issues by synthesizing the bean pod cube hollow metal-organic framework (MOF)-SnSx/NC@N-doped carbon nanofibers through a process involving electrospinning, PDA coating, and calcination. The Sn-MOF serves as a self-sacrificing template, facilitating the simultaneous dissociation of MOF and polymerization of dopamine, leading to the creation of hollow intermediates that retain tin components. Subsequent sulfidation results in the integration of the hollow MOF-SnSx/NC nanoparticles within 3D nitrogen-doped carbon nanofibers, forming the distinctive bean pod cube composite structure. This unique configuration effectively shortens the diffusion path and mitigates volume expansion for sodium ions, ultimately yielding an exceptional high rate performance of 130 mA h g-1 (10 A g-1) and an ultralong cycling performance of 328 mA h g-1 even after 3500 cycles (2 A g-1) as the anode for SIBs.

Expression of tissue levels of matrix metalloproteinases and tissue inhibitors of metalloproteinases in renal cell carcinoma.

BACKGROUND: Matrix metalloproteinases (MMPs) are one of the major classes of proteolytic enzymes involved in tumor invasion and metastasis and are inhibited by naturally occurring tissue inhibitors of metalloproteinases (TIMPs). {AU Query: Please verify that corrections made to previous sentence did not alter intended meaning}. In this study, we examined the expression of MMP-2, MMP-9, membrane-type 1 (MT1)-MMP, TIMP-1, and TIMP-2 in renal tissue samples of renal cell cancer and examined the correlation between their expression and clinicopathological parameters. METHODS: Renal tissue samples from 76 patients with renal cell carcinoma were available for this study. To determine the expression of MMP-2, MMP-9, MT1-MMP, TIMP-1, and TIMP-2, semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) was carried out on tumor and normal tissues. RESULTS: Mean MMP-2, MMP-9, MT1-MMP, TIMP-1, and TIMP-2 mRNA expression in the renal cell carcinomas was significantly higher than in the normal renal tissue (P <0.05). The RT-PCR data of MMP-2, MMP-9, MT1-MMP, TIMP-1, and TIMP-2 did not show any significant correlation with tumor type or pathologic grade of renal cell carcinoma. MMP-2, MMP-9 and MT1-MMP mRNA expression increased significantly with the TNM stage of the tumor. CONCLUSIONS: Mean MMP-2, MMP-9, MT1-MMP, TIMP-1, and TIMP-2 mRNA expression in the renal cell carcinomas was significantly higher than in the normal renal tissue.

Fiscal decentralization, industrial structure upgrading, and carbon emissions: evidence from China.

The debate over the role of fiscal decentralization and industrial structure upgrading in China's environmental governance has received increasing attention. Based on China's provincial panel data from 2003 to 2019, this paper investigates the impact of fiscal decentralization and industrial structure upgrading on carbon emissions to provide empirical evidence for the above theoretical argument. The results show that fiscal decentralization and industrial structure upgrading are negatively correlated with carbon emissions, while the interaction term for fiscal decentralization with industrial structure upgrading presents a facilitating effect on carbon emissions. Besides, fiscal decentralization, industrial structure upgrading, and the interaction term have significant regional heterogeneity on carbon emissions. When fiscal decentralization and industrial structure upgrading are taken as threshold variables, the effects of industrial structure upgrading and fiscal decentralization are significantly nonlinear. Moreover, environmental regulation, transportation infrastructure, and carbon emissions are positively correlated. There exists an inverted U-shaped relationship between carbon emissions and economic growth, which proves environmental Kuznets curve theorem. However, FDI and urbanization have no significant effect on carbon emissions. According to the above conclusions, it is necessary to strengthen the positive interaction between fiscal decentralization and industrial structure upgrading in mitigating carbon emissions, promoting the green and low-carbon transformation of China's economy, thus realizing the goals of "carbon peak" and "carbon neutrality."

Plasma modification of graphene nanoplatelets surfaces.

Atmospheric plasma processing, which combines the efficacy of chemical processes and the safety of physical processes, has been used to modify the surface characteristics of graphite-based materials. In this work, two distinct plasma source gases, C4F8 and O2, with the addition of a rotary reactor were used. The effectiveness of modifying the basal plane of intercalated graphite nanoplatelets (GnP) was investigated with various analytical techniques and the visual observation of the dispersion of these plasma-treated GnP in solvents was also reported. It is shown that this low-temperature plasma processing technique can be used to successfully modify the GnP surface without significantly changing the intrinsic structure of the GnP, which is desirable in many applications. With the C4F8 plasma treatment, the immersion characteristics in solvents can be tuned and the functional groups present on the surface can be tailored to produce desired bonding environments. This surface chemistry tunability will provide the needed functionalities in creating graphene-containing composite materials.

Modulation of poly (acrylic acid) hydrogels with κ-carrageenan for high-performance quasi-solid Al-air batteries.

Primary quasi-solid Al-air batteries using hydrogels have attracted increasing research attention owing to their high energy density, good handling, safety and reliability. However, it is still difficult to develop hydrogel electrolytes with high ionic conductivity and water retention owing to limited capacity of single material hydrogels. Herein, we report a hydrogel electrolyte of poly (acrylic acid) (PAA) is modified by κ-carrageenan (KC) for solid-state Al-air batteries. The result suggests that the hydrogels not only exhibit outstanding water retention but also high ionic conductivity, which is attributed to the amorphous phase and hydrophilic group of the KC. Additionally, the lifespan of solid-state Al-air battery is extended at a current density of 5 mA cm-2 owing to adding KC. Further, the lifetime of open Al-air batteries is improved by self-corrosion inhibition of Al anode.

Environmental regulation, industrial agglomeration, and marine green development efficiency: an empirical analysis from China's coastal provinces.

Environmental regulation (ER) and industrial agglomeration (IA) are important factors that affect green development efficiency (GDE). However, there is a lack of studies on their relation in the context of the marine economy. This paper integrates ER, IA, and marine GDE (MGDE) into a unified analytical framework and uses balanced panel data from China's 11 coastal provinces during 2008-2019 to quantify the linear, nonlinear, and spatial spillover effects between the three using the spatial Durbin model (SDM) and threshold effect model. The results show that ER has a negative impact on local and surrounding MGDE through the direct and spatial spillover effects. IA has a positive impact on local and surrounding MGDE through direct and spatial spillover effects. The synergistic impact of ER and IA can significantly boost local and surrounding MGDE. When ER surpasses a certain threshold, it amplifies the positive impact of IA on MGDE. These findings offer theoretical and practical references for the Chinese government to formulate marine environmental governance and industrial development policies.

Stable Ultra-thin Silver Films Grown by Soft Ion Beam-Enhanced Sputtering with an Aluminum Cap Layer.

Ultra-thin silver films are susceptible to ambient environments and form grayish layers in the silver mirroring process. The poor wettability together with the high diffusivity of surface atoms in the presence of oxygen accounts for the thermal instability of ultra-thin silver films in the air and at elevated temperatures. This work demonstrates an atomic-scale aluminum cap layer on the silver to enhance the thermal and environmental stabilities of ultra-thin silver films deposited by sputtering with the assistance of a soft ion beam reported in our previous work. The resulted film consists of an ion-beam-treated seed silver layer of ∼1 nm nominal thickness, a subsequent silver layer of ∼6 nm thickness produced by sputtering alone, and an aluminum cap layer of ∼0.2 nm nominal thickness. Although the aluminum cap is only one to two atomic layers and likely non-continuous, it significantly improved the thermal and ambient environmental stability of the ultra-thin silver films (∼7 nm thick) without affecting the film's optical and electrical properties. The improved environmental stability is attributed to the cathodic protection mechanism and reduced diffusivity of surface atoms. The improved thermal stability is attributed to the reduced mobility of surface atoms in the presence of aluminum atoms. Thermal treatment of the duplex film also improves the film's electrical conductivity and optical transmittance by enhancing its crystallinity. The annealed aluminum/silver duplex structure has exhibited the lowest electric resistivity among the reported ultra-thin silver films and high optical transmittance similar to the simulated theoretical results.

The impact of low-carbon city pilot policy on green total-factor productivity in China's cities.

Whether the low-carbon city construction can coordinate urban economy and environment has attracted increasing attention in recent years. In this study, the impact of low-carbon city pilot (LCCP) policy on urban green total-factor productivity is systematically examined theoretically and empirically. Specifically, the biennial Malmquist-Luenberger (BML) index is adopted to measure urban green productivity. Then, propensity score matching-difference-in-differences (PSM-DID) and spatial DID model are used to quantitatively identify the local and spatial spillover effect of the LCCP policy on urban green productivity during 2004-2018 in China. The results show that (1) The LCCP policy can significantly promote urban green productivity, as confirmed through a series of robustness tests. (2) For transmission mechanism, the LCCP policy can enhance urban green productivity through energy consumption reduction and technological innovation but not through industrial structure optimization. (3) With regard to heterogeneity, cities with better transportation infrastructure, stricter environmental regulation and higher urbanization level, as well as non-resource-based cities have more significantly positive effects of the LCCP policy on urban green productivity. (4) The LCCP policy mainly relies on technological progress rather than technical efficiency improvement to drive urban green productivity. (5) The LCCP policy's effect on urban green productivity has significant positive spatial spillover feature, which can significantly promote green productivity in both pilot cities and their neighboring cities. Our findings can provide valuable insights for low-carbon city construction to promote urban sustainable development in China.

Characterization of chemical transport in human skin and building material.

Volatile organic compounds (VOCs) and semi-volatile organic compounds (SVOCs) are ubiquitous in indoor environment. They can emit from source into air, and subsequently penetrate human skin into blood through dermal uptake, causing adverse health effects. This study develops a two-layer analytical model to characterize the VOC/SVOC dermal uptake process, which is then extended to predict VOC emissions from two-layer building materials or furniture. Based on the model, the key transport parameters of chemicals in every skin or material layer are determined via a hybrid optimization method using data from experiments and literature. The measured key parameters of SVOCs for dermal uptake are more accurate than those from previous studies using empirical correlations. Moreover, the association between the absorption amount of studied chemicals into blood and age is preliminarily investigated. Further exposure analysis reveals that the contribution of dermal uptake to the total exposure can be comparable with that of inhalation for the examined SVOCs. This study makes the first attempt to accurately determine the key parameters of chemicals in skin, which is demonstrated to be critical for health risk assessment.

A fluoropolymer bifunctional solid membrane interface for improving the discharge duration in aqueous Al-air batteries.

Herein, a fluoropolymer bifunctional solid membrane interface (SMI) for an aqueous Al-air battery is proposed, which inhibits anodic self-corrosion, while concurrently reducing the accumulation of undesirable by-products. A battery using the SMI exhibits a remarkable anticorrosion efficiency of 81.31% and achieves an astonishing battery lifetime improvement rate of 184.37% under the condition of 5 min intermittent discharge.

Economic Growth Targets and Carbon Emissions: Evidence from China.

Carbon emissions have become a new threat to sustainable development in China, and local government actions can play an important role in energy conservation and emission reduction. This paper explores the theoretical mechanisms and transmission paths of economic growth targets affecting carbon emissions from the perspective of economic growth targets and conducts an empirical analysis based on 30 provincial panel data in China from 2003 to 2019. The results show that: economic growth targets are positively correlated with carbon emissions under a series of endogeneity and robustness; there are regional heterogeneity, target heterogeneity and structural heterogeneity in the impact of economic growth targets on carbon emissions; after economic growth targets are set, government actions can influence carbon emissions by affecting resource mismatch and industrial restructuring; It is further found that there is a "U" shaped relationship between economic pressure and carbon emissions. Based on the above findings, this paper further proposes that a high-quality performance assessment mechanism should be developed to bring into play the active role of local governments in achieving carbon reduction goals, and thus contribute to high-quality economic development.