Tailoring Oxygen Reduction Reaction Kinetics of Fe-N-C Catalyst via Spin Manipulation for Efficient Zinc-Air Batteries.

The interaction between oxygen species and metal sites of various orbitals exhibits intimate correlation with the oxygen reduction reaction (ORR) kinetics. Herein, a new approach for boosting the inherent ORR activity of atomically dispersed Fe-N-C matrix is represented by implanting Fe atomic clusters nearby. The as-prepared catalyst delivers excellent ORR activity with half-wave potentials of 0.78 and 0.90 V in acidic and alkaline solutions, respectively. The decent ORR activity can also be validated from the high-performance rechargeable Zn-air battery. The experiments and density functional theory calculations reveal that the electron spin-state of monodispersed Fe active sites is transferred from the low spin (LS, t2g 6 eg 0) to the medium spin (MS, t2g 5 eg 1) due to the involvement of Fe atomic clusters, leading to the spin electron filling in σ∗ orbit, by which it favors OH- desorption and in turn boosts the reaction kinetics of the rate-determining step. This work paves a solid way for rational design of high-performance Fe-based single atom catalysts through spin manipulation.

Autophagy Induced by Low Shear Stress Leads to Endothelial Glycocalyx Disruption.

INTRODUCTION: Previous studies have confirmed that low shear stress (LSS) induces glycocalyx disruption, leading to endothelial dysfunction. However, the role of autophagy in LSS-induced glycocalyx disruption and relevant mechanism are not clear. In this study, we hypothesized that LSS may promote autophagy, disrupting the endothelium glycocalyx. METHODS: Human umbilical vein endothelial cells were subjected to physiological shear stress and LSS treatments, followed by the application of autophagy inducers and inhibitors. Additionally, cells were treated with specific matrix metalloproteinase-2 (MMP-2) and matrix metalloproteinase-9 (MMP-9) inhibitor. The expression of autophagic markers, glycocalyx, MMP-2, and MMP-9 was measured. RESULTS: LSS impacted the expression of endothelium autophagy markers, increasing the expression of LC3II.LC3I-1 and Beclin-1, and decreasing the levels of p62, accompanied by glycocalyx disturbance. Moreover, LSS upregulated the expression of MMP-2 and MMP-9 and downregulated the levels of syndecan-1 and heparan sulfate (HS). Additionally, expression of MMP-2 and MMP-9 was increased by an autophagy promoter but was decreased by autophagy inhibitor treatment under LSS. Autophagy and MMP-2 and MMP-9 further caused glycocalyx disruption. CONCLUSION: LSS promotes autophagy, leading to glycocalyx disruption. Autophagy increases the expression of MMP-2 and MMP-9, which are correlated with the glycocalyx destruction induced by LSS.

Designing State-of-the-Art Gas Sensors: From Fundamentals to Applications.

Gas sensors are crucial in environmental monitoring, industrial safety, and medical diagnostics. Due to the rising demand for precise and reliable gas detection, there is a rising demand for cutting-edge gas sensors that possess exceptional sensitivity, selectivity, and stability. Due to their tunable electrical properties, high-density surface-active sites, and significant surface-to-volume ratio, nanomaterials have been extensively investigated in this regard. The traditional gas sensors utilize homogeneous material for sensing where the adsorbed surface oxygen species play a vital role in their sensing activity. However, their performance for selective gas sensing is still unsatisfactory because the employed high temperature leads to the poor stability. The heterostructures nanomaterials can easily tune sensing performance and their different energy band structures, work functions, charge carrier concentration and polarity, and interfacial band alignments can be precisely designed for high-performance selective gas sensing at low temperature. In this review article, we discuss in detail the fundamentals of semiconductor gas sensing along with their mechanisms. Further, we highlight the existed challenges in semiconductor gas sensing. In addition, we review the recent advancements in semiconductor gas sensor design for applications from different perspective. Finally, the conclusion and future perspectives for improvement of the gas sensing performance are discussed.

Predictive role of glycocalyx components and MMP-9 in cardiopulmonary bypass patients for ICU stay.

Background: Shedding of glycocalyx is relevant to worse prognosis in surgical patients, and elevated levels of serum matrix metalloproteinase-9 (MMP-9) are associated with this phenomenon. This study aimed to investigate the dynamic alterations of serum glycocalyx components and MMP-9 during cardiopulmonary bypass (CPB), and evaluate their predictive capacities for prolonged intensive care unit (ICU) stay, as well as their correlation with coagulation dysfunction. Methods: This retrospective study analyzed serum levels of syndecan-1, heparan sulfate (HS), and MMP-9 at different time points during CPB, and assessed their association with prolonged ICU stay and coagulation dysfunction. Results: Syndecan-1, HS, and MMP-9 exhibited divergent changes during CPB. Serum levels of syndecan-1 (AUC = 78.0 %) and MMP-9 (AUC = 78.4 %) were validated as reliable predictors for prolonged ICU stay, surpassing the predictive value of creatinine (AUC = 70.0 %). Syndecan-1 (rho = 0.566, P < 0.01 at T1 and rho = 0.526, P < 0.01 at T2) and HS (rho = 0.403, P < 0.05 at T4) exhibited correlations with activated partial thromboplastin time (APTT) ratio beyond the normal range. Conclusions: Our findings advocate the potential efficacy of serum glycocalyx components and MMP-9 as early predictive indicators for extended ICU stay following cardiac surgery with CPB. Additionally, we observed a correlation between glycocalyx disruption during CPB and coagulation dysfunction. Further studies with expansive cohorts are warranted to consolidate our findings and explore the predictive potential of other glycocalyx components.

A motif for B/O-site modulation in LaFeO3 towards boosted oxygen evolution.

Here, a series of transition metal (Ni) doped iron-based perovskite oxides LaFe1-xNixO3-δ (x = 0, 0.25, 0.5, 0.75, 1) were prepared, and then the perovskite oxide with the optimized nickel-iron ratio was doped with non-metallic elements (N). Experimental and theoretical investigations reveal that the co-doping breaks the traditional linear constraint relationship (GOOH - GOH = 3.2 eV) and the theoretical overvoltage is reduced from 0.64 V (LaFeO3-δ) to 0.44 V (LaFe0.5Ni0.5O3-δ/N). Specifically, Ni-doping can accelerate electron transfer and improve the conductivity. Moreover, N-doping can reduce the adsorption energy of *OH/*O and enhance the adsorption energy of *OOH. We demonstrated that the optimized cation and anion co-doped LaFe0.5Ni0.5O3-δ/N perovskite oxide exhibits an excellent OER performance, with a low overpotential of 270.6 mV at 10 mA cm-2 and a small Tafel slope of 65 mV dec-1 in 1 M KOH solution, markedly exceeding that of the parent perovskite oxide LaFeO3-δ (300.9 mV) and commercial IrO2 (289.1 mV). It also delivers decent durability with no significant degradation after a 35 h stability test. This work reveals the internal mechanism of perovskite oxide by doping cation and anion for water oxidation, which broadens the idea for the rational design of new perovskite-based sustainable energy catalysts.

Manipulation of Electron Spins with Oxygen Vacancy on Amorphous/Crystalline Composite-Type Catalyst.

By substituting the oxygen evolution reaction (OER) with the anodic urea oxidation reaction (UOR), it not only reduces energy consumption for green hydrogen generation but also allows purification of urea-rich wastewater. Spin engineering of the d orbital and oxygen-containing adsorbates has been recognized as an effective pathway for enhancing the performance of electrocatalysts. In this work, we report the fabrication of a bifunctional electrocatalyst composed of amorphous RuO2-coated NiO ultrathin nanosheets (a-RuO2/NiO) with abundant amorphous/crystalline interfaces for hydrogen evolution reaction (HER) and UOR. Impressively, only 1.372 V of voltage is required to attain a current density of 10 mA cm-2 over a urea electrolyzer. The increased oxygen vacancies in a-RuO2/NiO by incorporation of amorphous RuO2 enhance the total magnetization and entail numerous spin-polarized electrons during the reaction, which speeds up the UOR reaction kinetics. The density functional theory study reveals that the amorphous/crystalline interfaces promote charge-carrier transfer, and the tailored d-band center endows the optimized adsorption of oxygen-generated intermediates. This kind of oxygen vacancy induced spin-polarized electrons toward boosting HER and UOR kinetics and provides a reliable reference for exploration of advanced electrocatalysts.

Exceptional green hydrogen production performance of a ruthenium-modulated nickel selenide.

Developing low-cost, high-efficiency and stable electrocatalysts for the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) is crucial but highly challenging. Density functional theory (DFT) calculations reveal that doping ruthenium (Ru) into catalysts can effectively optimize their electronic structure, hence leading to an optimal Gibbs free energy on the catalyst surface. Herein, an ultra-low Ru (about 2.34 wt%)-doped Ni3Se2 nanowire catalyst (i.e., Ru/Ni3Se2) supported on nickel foam has been fabricated by a hydrothermal reaction followed by a chemical etching process. The unique three-dimensional (3D) interconnected nanowires not only endow Ru and Ni3Se2 with uniform distribution and coupling, but also provide higher electrical conductivity, more active sites, an optimized electronic structure and favorable reaction kinetics. Therefore, the as-obtained Ru/Ni3Se2 catalyst exhibits excellent electrocatalytic performance, with low overpotentials of 24 and 211 mV to supply a current density value of 10 mA cm-2 towards the HER and OER in an alkaline environment, respectively. Notably, the as-fabricated Ru/Ni3Se2 catalyst only requires a low voltage of 1.476 V to derive a current density of 10 mA cm-2 in the constructed two-electrode alkaline electrolyzer and exhibits exceptionally high stability. This work will provide a novel strategy for the design and fabrication of low-cost and high-performance bifunctional electrocatalysts for hydrogen production by water electrolysis.

Interface Engineering Induced Electron Redistribution at PtNs /NiTe-Ns Interfaces for Promoting pH-Universal and Chloride-Tolerant Hydrogen Evolution Reaction.

Exploring highly efficient hydrogen evolution reaction (HER) electrocatalysts for large-scale water electrolysis in the full potential of hydrogen (pH) range is highly desirable, but it remains a significant challenge. Herein, a simple pathway is proposed to synthesize a hybrid electrocatalyst by decorating small metallic platinum (Pt) nanosheets on a large nickel telluride nanosheet (termed as PtNs /NiTe-Ns). The as-prepared PtNs /NiTe-Ns catalyst only requires overpotentials of 72, 162, and 65 mV to reach a high current density of 200 mA cm-2 in alkaline, neutral and acidic conditions, respectively. Theoretical calculations reveal that the combination of metallic Pt and NiTe-Ns subtly modulates the electronic redistribution at their interface, improves the charge-transfer kinetics, and enhances the performance of Ni active sites. The synergy between the Pt site and activated Ni site near the interface in PtNs /NiTe-Ns promotes the sluggish water-dissociation kinetics and optimizes the subsequent oxyhydrogen/hydrogen intermediates (OH*/H*) adsorption, accelerating the HER process. Additionally, the superhydrophilicity and superaerophobicity of PtNs /NiTe-Ns facilitate the mass transfer process and ensure the rapid desorption of generated bubbles, significantly enhancing overall alkaline water/saline water/seawater electrolysis catalytic activity and stability.

Leveraging Metal Nodes in Metal-Organic Frameworks for Advanced Anodic Hydrazine Oxidation Assisted Seawater Splitting.

Metal-organic frameworks (MOFs) show great promise for electrocatalysis owing to their tunable ligand structures. However, the poor stability of MOFs impedes their practical applications. Unlike the general pathway for engineering ligands, we report herein an innovative strategy for leveraging metal nodes to improve both the catalytic activity and the stability. Our electrolysis cell with a NiRh-MOF||NiRh-MOF configuration exhibited 10 mA cm-2 at an ultralow cell voltage of 0.06 V in alkaline seawater (with 0.3 M N2H4), outperforming its counterpart benchmark Pt/C||Pt/C cell (0.12 V). Impressively, the incorporation of Rh into a MOF secured a robust stability of over 60 h even when working in the seawater electrolyte. Experimental results and theoretical calculations revealed that Rh atoms serve as the active sites for hydrogen evolution while Ni nodes are responsible for the hydrazine oxidation during the hydrazine oxidation assisted seawater splitting. This work provides a paradigm for green hydrogen generation from seawater.

Constrained C2 adsorbate orientation enables CO-to-acetate electroreduction.

The carbon dioxide and carbon monoxide electroreduction reactions, when powered using low-carbon electricity, offer pathways to the decarbonization of chemical manufacture1,2. Copper (Cu) is relied on today for carbon-carbon coupling, in which it produces mixtures of more than ten C2+ chemicals3-6: a long-standing challenge lies in achieving selectivity to a single principal C2+ product7-9. Acetate is one such C2 compound on the path to the large but fossil-derived acetic acid market. Here we pursued dispersing a low concentration of Cu atoms in a host metal to favour the stabilization of ketenes10-chemical intermediates that are bound in monodentate fashion to the electrocatalyst. We synthesize Cu-in-Ag dilute (about 1 atomic per cent of Cu) alloy materials that we find to be highly selective for acetate electrosynthesis from CO at high *CO coverage, implemented at 10 atm pressure. Operando X-ray absorption spectroscopy indicates in situ-generated Cu clusters consisting of <4 atoms as active sites. We report a 12:1 ratio, an order of magnitude increase compared to the best previous reports, in the selectivity for acetate relative to all other products observed from the carbon monoxide electroreduction reaction. Combining catalyst design and reactor engineering, we achieve a CO-to-acetate Faradaic efficiency of 91% and report a Faradaic efficiency of 85% with an 820-h operating time. High selectivity benefits energy efficiency and downstream separation across all carbon-based electrochemical transformations, highlighting the importance of maximizing the Faradaic efficiency towards a single C2+ product11.

Engineering Amorphous/Crystalline Ru(OH)3/CoFe-Layered Double Hydroxide for Hydrogen Evolution at 1000 mA cm-2.

For large-scale industrial applications, it is highly desirable to create effective, economical electrocatalysts with long-term stability for the hydrogen evolution reaction (HER) at a large current density. Herein, we report a unique motif with crystalline CoFe-layered hydroxide (CoFe-LDH) nanosheets enclosed by amorphous ruthenium hydroxide (a-Ru(OH)3/CoFe-LDH) to realize the efficient hydrogen production at 1000 mA cm-2, with a low overpotential of 178 mV in alkaline media. During the continuous HER process for 40 h at such a large current density, the potential remains almost constant with only slight fluctuations, indicating good long-term stability. The remarkable HER performance can be attributed to the charge redistribution caused by abundant oxygen vacancies in a-Ru(OH)3/CoFe-LDH. The increased electron density of states lowers the charge-transfer resistance and promotes the formation and release of H2 molecules. The water-splitting electrolyzer with a-Ru(OH)3/CoFe-LDH as both an anode and a cathode in 1.0 M KOH demonstrates stable hydrogen production and a 100% faradic efficiency. The design strategy of interface engineering in this work will inspire the design of practical electrocatalysts for water splitting on an industrial scale.

Enhanced Photocatalytic H2 Evolution Performance of the Type-II FeTPPCl/Porous g-C3N4 Heterojunction: Experimental and Density Functional Theory Studies.

It is of great significance to improve the photocatalytic performance of g-C3N4 by promoting its surface-active sites and engineering more suitable and stable redox couples. Herein, first of all, we fabricated porous g-C3N4 (PCN) via the sulfuric acid-assisted chemical exfoliation method. Then, we modified the porous g-C3N4 with iron(III) meso-tetraphenylporphine chloride (FeTPPCl) porphyrin via the wet-chemical method. The as-fabricated FeTPPCl-PCN composite revealed exceptional performance for photocatalytic water reduction by evolving 253.36 and 8301 µmol g-1 of H2 after visible and UV-visible irradiation for 4 h, respectively. The performance of the FeTPPCl-PCN composite is ∼2.45 and 4.75-fold improved compared to that of the pristine PCN photocatalyst under the same experimental conditions. The calculated quantum efficiencies of the FeTPPCl-PCN composite for H2 evolution at 365 and 420 nm wavelengths are 4.81 and 2.68%, respectively. This exceptional H2 evolution performance is because of improved surface-active sites due to porous architecture and remarkably improved charge carrier separation via the well-aligned type-II band heterostructure. Besides, we also reported the correct theoretical model of our catalyst through density functional theory (DFT) simulations. It is found that the hydrogen evolution reaction (HER) activity of FeTPPCl-PCN arises from the electron transfer from PCN via Cl atom(s) to Fe of the FeTPPCl, which forms a strong electrostatic interaction, leading to a decreased local work function on the surface of the catalyst. We suggest that the resultant composite would be a perfect model for the design and fabrication of high-efficiency heterostructure photocatalysts for energy applications.

IMGC-GNN: A multi-granularity coupled graph neural network recommendation method based on implicit relationships.

In the application recommendation field, collaborative filtering (CF) method is often considered to be one of the most effective methods. As the basis of CF-based recommendation methods, representation learning needs to learn two types of factors: attribute factors revealed by independent individuals (e.g., user attributes, application types) and interaction factors contained in collaborative signals (e.g., interactions influenced by others). However, existing CF-based methods fail to learn these two factors separately; therefore, it is difficult to understand the deeper motivation behind user behaviors, resulting in suboptimal performance. From this point of view, we propose a multi-granularity coupled graph neural network recommendation method based on implicit relationships (IMGC-GNN). Specifically, we introduce contextual information (time and space) into user-application interactions and construct a three-layer coupled graph. Then, the graph neural network approach is used to learn the attribute and interaction factors separately. For attribute representation learning, we decompose the coupled graph into three homogeneous graphs with users, applications, and contexts as nodes. Next, we use multilayer aggregation operations to learn features between users, between contexts, and between applications. For interaction representation learning, we construct a homogeneous graph with user-context-application interactions as nodes. Next, we use node similarity and structural similarity to learn the deep interaction features. Finally, according to the learned representations, IMGC-GNN makes accurate application recommendations to users in different contexts. To verify the validity of the proposed method, we conduct experiments on real-world interaction data from three cities and compare our model with seven baseline methods. The experimental results show that our method has the best performance in the top-k recommendation.

Highly efficient overall urea electrolysis via single-atomically active centers on layered double hydroxide.

Anodic urea oxidation reaction (UOR) is an intriguing half reaction that can replace oxygen evolution reaction (OER) and work together with hydrogen evolution reaction (HER) toward simultaneous hydrogen fuel generation and urea-rich wastewater purification; however, it remains a challenge to achieve overall urea electrolysis with high efficiency. Herein, we report a multifunctional electrocatalyst termed as Rh/NiV-LDH, through integration of nickel-vanadium layered double hydroxide (LDH) with rhodium single-atom catalyst (SAC), to achieve this goal. The electrocatalyst delivers high HER mass activity of 0.262 A mg-1 and exceptionally high turnover frequency (TOF) of 2.125 s-1 at an overpotential of 100 mV. Moreover, exceptional activity toward urea oxidation is addressed, which requires a potential of 1.33 V to yield 10 mA cm-2, endorsing the potential to surmount the sluggish OER. The splendid catalytic activity is enabled by the synergy of the NiV-LDH support and the atomically dispersed Rh sites (located on the Ni-V hollow sites) as evidenced both experimentally and theoretically. The self-supported Rh/NiV-LDH catalyst serving as the anode and cathode for overall urea electrolysis (1 mol L-1 KOH with 0.33 mol L-1 urea as electrolyte) only requires a small voltage of 1.47 V to deliver 100 mA cm-2 with excellent stability. This work provides important insights into multifunctional SAC design from the perspective of support sites toward overall electrolysis applications.

N-doped graphene for electrocatalytic O2 and CO2 reduction.

The electrocatalytic CO2 reduction reaction (CO2RR) and oxygen reduction reaction (ORR) are important approaches to realize energy conversion and sustainable development. However, sluggish reaction kinetics severely hinders the practical application of devices related to these reactions. N-doped graphene (NG) with unique properties exhibits great potential in catalyzing the CO2RR and ORR, which is attributed to the electron redistribution. In this review, we start from the fundamental properties of NG, especially emphasizing the changes caused by N doping. Then the synthetic methods are summarized by classifying them into top-down strategies and bottom-up strategies. Subsequently, the applications of NG in the ORR and CO2RR are discussed and the effects of electronic structure on the electrocatalytic activity are highlighted. Finally, we give our own perspective on the future research direction of NG in the applications of the ORR and CO2RR.

Engineering Amorphous/Crystalline Rod-like Core-Shell Electrocatalysts for Overall Water Splitting.

The design of bifunctional electrocatalysts for hydrogen and oxygen evolution reactions delivering excellent catalytic activity and stability is highly desirable, yet challenged. Herein, we report an amorphous RuO2-encapsulated crystalline Ni0.85Se nanorod structure (termed as a/c-RuO2/Ni0.85Se) for enhanced HER and OER activities. The as-prepared a/c-RuO2/Ni0.85Se nanorods not only demonstrate splendid HER activity (58 mV@10 mA cm-2 vs RHE), OER activity (233 mV@10 mA cm-2 vs RHE), and electrolyzer activity (1.488 V@10 mA cm-2 vs RHE for overall water splitting) but also exhibit long-term stability with negligible performance decay after 50 h continuous test for overall water splitting. In addition, the variation of the d-band center (from the perspective of bonding and antibonding states) is unveiled theoretically by density functional theory calculations upon amorphous RuO2 layers coupling to clarify the increased hydrogen species adsorption for HER activity enhancement. This work represents a new pathway for the fabrication of bifunctional electrocatalysts toward green hydrogen generation.

Synthesis and Micromechanistic Studies of Sensitized Bentonite for Methyl Orange and Rhodamine-B Adsorption from Wastewater: Experimental and DFT-Based Analysis.

This work reports the formation of a novel adsorbent, prepared by activating bentonite with cinnamic acid, which is highly efficient to remove dyes from wastewater. The adsorption efficiency of the cinnamic acid activated bentonite was compared with unmodified bentonite by removing methyl orange and rhodamine-B from polluted water. The characterization was performed through X-ray diffraction (XRD) Fourier transform infrared (FTIR) and scanning electron microscopy (SEM). The results indicated that acidic pH and low temperature were more suitable for the selected dyes adsorption. The analysis of the data was done by the Langmuir and Freundlich isotherms; the Freundlich isotherm showed more suitability for the equilibrium data. The data were further analyzed by pseudo-first and pseudo-second-order models to study adsorption kinetics. The results showed that methyl orange and rhodamine-B adsorption obeyed pseudo-order kinetics. The results obtained from this research suggested that acid activation of bentonite with cinnamic acid increased the surface area of the clay and hence enhanced its adsorption efficiency. The maximum adsorption efficiency for the removal of methyl orange and rhodamine-B was up to 99.3 mg g-1 and 44.7 mg g-1, respectively, at 25 °C. This research provides an economical modification technique of bentonite, which makes it cost-effective and a good adsorbent for wastewater treatment.

Metal-Organic Frameworks Offering Tunable Binary Active Sites toward Highly Efficient Urea Oxidation Electrolysis.

Electrocatalytic urea oxidation reaction (UOR) is regarded as an effective yet challenging approach for the degradation of urea in wastewater into harmless N2 and CO2. To overcome the sluggish kinetics, catalytically active sites should be rationally designed to maneuver the multiple key steps of intermediate adsorption and desorption. Herein, we demonstrate that metal-organic frameworks (MOFs) can provide an ideal platform for tailoring binary active sites to facilitate the rate-determining steps, achieving remarkable electrocatalytic activity toward UOR. Specifically, the MOF (namely, NiMn0.14-BDC) based on Ni/Mn sites and terephthalic acid (BDC) ligands exhibits a low voltage of 1.317 V to deliver a current density of 10 mA cm-2. As a result, a high turnover frequency (TOF) of 0.15 s-1 is achieved at a voltage of 1.4 V, which enables a urea degradation rate of 81.87% in 0.33 M urea solution. The combination of experimental characterization with theoretical calculation reveals that the Ni and Mn sites play synergistic roles in maneuvering the evolution of urea molecules and key reaction intermediates during the UOR, while the binary Ni/Mn sites in MOF offer the tunability for electronic structure and d-band center impacting on the intermediate evolution. This work provides important insights into active site design by leveraging MOF platform and represents a solid step toward highly efficient UOR with MOF-based electrocatalysts.

A Single-Atom Fe-N-C Catalyst with Ultrahigh Utilization of Active Sites for Efficient Oxygen Reduction.

Fe-N-C single-atom catalysts (SACs) are emerging as a promising class of electrocatalysts for the oxygen reduction reaction (ORR) to replace Pt-based catalysts. However, due to the limited loading of Fe for SACs and the inaccessibility of internal active sites, only a small portion of the sites near the external surface are able to contribute to the ORR activity. Here, this work reports a metal-organic framework-derived Fe-N-C SAC with a hierarchically porous and concave nanoarchitecture prepared through a facile but effective strategy, which exhibits superior electrocatalytic ORR activity with a half-wave potential of 0.926 V (vs RHE) in alkaline media and 0.8 V (vs RHE) in acidic media while maintaining excellent stability. The superior ORR activity of the as-designed catalyst stems from the unique architecture, where the hierarchically porous architecture contains micropores as Fe SAC anchoring sites, meso-/macro-pores as accessible channels, and concave shell for increasing external surface area. The unique architecture has dramatically enhanced the utilization of previously blocked internal active sites, as confirmed by a high turnover frequency of 3.37 s-1 and operando X-ray absorption spectroscopy analysis with a distinct shift of adsorption edge.

Ultrasonic-assisted decoration of Ag2WO4, AgI, and Ag nanoparticles over tubular g-C3N4: Plasmonic photocatalysts for impressive removal of tetracycline under visible light.

The development of an efficient, eco-friendly, and low-cost photocatalyst is essential for addressing environmental and energy crises. In this regard, we report novel plasmonic photocatalysts through adorning tubular g-C3N4 with Ag2WO4, Ag, and AgI nanoparticles (TGCN/Ag/Ag2WO4/AgI) fabricated via a facile ultrasonic-irradiation procedure. The TGCN/Ag/Ag2WO4/AgI (20%) nanocomposite presented the excellent photocatalytic ability for removal of tetracycline hydrochloride under visible light, which was almost 45.6, 4.03, and 1.32 times more than GCN, TGCN, and TGCN/Ag/Ag2WO4 (20%) photocatalysts, respectively. Interestingly, the photocatalyst displayed impressive ability for the degradations of amoxicilline, rhodamine B, methyl orange, fuchsine, and methylene blue, which was 14.7, 52.2, 9.8, 13.2, and 7.46 times as much as pure GCN. The outcomes of DRS, PL, EIS, and photocurrent density analyses proved that the impressive activity could be related to the highly promoted harvesting of visible light, segregation of charge carriers, and improved charge migrations. In addition, trapping tests exhibited that •O2- and h+ were active species in the photocatalysis process.