Anchor Sites Research Articles

Tailored Polymer Hole-Transporting Materials with Multisite Passivation Functions for Effective Buried-Interface Engineering of Inverted Quasi-2D Perovskite Solar Cells.

Although quasi-2D Ruddlesden‒Popper (RP) perovskite exhibits advantages in stability, their photovoltaic performance are still inferior to 3D counterparts. Optimizing the buried interface of RP perovskite and suppress energetic losses can be a promising approach for enhancing efficiency and stability of inverted quasi-2D RP perovskite solar cells (PSCs). Among which, constructing polymer hole-transporting materials (HTMs) with defect passivation functions is of great significance for buried-interface engineering of inverted quasi-2D RP PSCs. Herein, by employing side-chain tailoring strategy to extend the π-conjugation and regulate functionality of side-chain groups, target polymer HTMs (PVCz-ThSMeTPA and PVCz-ThOMeTPA) with high mobility and multisite passivation functions are achieved. The presence of more sulfur atom-containing groups in side-chain endows PVCz-ThSMeTPA with increased intra/intermolecular interaction, appropriate energy level, and enhanced buried interfacial interactions with quasi-2D RP perovskite. The hole mobility of PVCz-ThSMeTPA is up to 9.20×10-4 cm2 V-1 S-1. Furthermore, PVCz-ThSMeTPA as multifunctional polymer HTM with multiple chemical anchor sites for buried-interface engineering of quasi-2D PSCs can enable effective charge extraction, defects passivation, and perovskite crystallization modulation. Eventually, the PVCz-ThSMeTPA-based inverted quasi-2D PSC achieves a champion power conversion efficiency of 22.37%, which represents one of the highest power conversion efficiencies reported to date for quasi-2D RP PSCs.

Nitrogen-rich carbon nanosheets supported copper catalysts for oxidative carbonylation of ethanol

Two-dimensional (2D) nitrogen-rich carbon nanosheets NC-x with a nitrogen content of 5.2 %-6.8 wt% were characterized by a one-step co-pyrolysis method and employed as Cu catalyst supports for oxidative carbonylation of ethanol. Carbon nanosheets with abundant nitrogen defects were achieved by tuning the dosage of ammonium oxalate, in which the Cu/NC-12 catalyst performed excellent activity. Furthermore, Cu/NC-x catalysts presented significantly superior catalytic activity than that of copper/carbon nanosheets (Cu/C) catalyst, it can be ascribed to the most suitable nitrogen doping to promote the exposure and dispersion of Cu species and pyridine nitrogen served as the main anchor sites to increase the ratio of Cu+/(Cu++Cu0). Density functional theory calculations further proved that introducing nitrogen atoms into carbon nanosheets effectively reinforced binding to Cu4 and adsorption of intermediates with NC, and a remarkable activity on Cu/NC-12 was achieved by a more favorable insertion of CO in the rate-determining step.

Stabilization of Pb/Zn mine tailings by modified fly ash: characterization, performance, and mechanism.

The presence of heavy metals in mine tailings poses a serious threat to the surrounding environment. In this study, we aimed to stabilize Pb/Zn-containing mine tailings using modified fly ash (FA) with various alkali solutions. Notably, the modification of FA with Na2SiO3 (NaSi-FA) resulted in the most significant structure changes. To understand the adsorption mechanism of Pb and Zn by modified FA, batch adsorption experiments were conducted. Doubling the adsorption capacity for both Pb and Zn was observed in the modified FA samples compared to unmodified samples. These results could be attributed to the enhanced surface area and porous structure, providing more anchor sites for the heavy metal ions. Additionally, the adsorption of Pb and Zn was found to follow the Langmuir isotherm and pseudo-second order kinetic. Molecular dynamics simulations further supported the notion that Pb and Zn ions could effectively exchange with Na ions within the N-A-S-H gel network, ultimately solidifying them in its structure. Stabilizing Pb/Zn tailings with NaSi-FA resulted in a significant decrease in the leaching of Pb and Zn. Specifically, the leading amount decreased by 55.2% for Pb and 35.3% for Zn, showcasing the superior performance of this stabilization method. This reduction in leaching indicates effective compliance with environmental regulations regarding the containment of Pb and Zn.

A rational construction of FexOy-N-ZSM-5 catalyst with graphene structures and FeNx sites for the selective catalytic oxidation of triethylamine

Stabilizing metal species at the atomic level and tuning their catalytic properties is a significant challenge. Herein, an N-doped FexOy-N-ZSM-5 catalyst with layered and chain-like graphene structures is reported. The catalyst can selectively catalyze the oxidation of triethylamine (TEA) with an efficiency of 99.7 % at 240 °C, and maintain an N2 yield of 97.6 % over the reaction temperature range of 240–360 °C. The results indicate that the layered graphene in the catalyst provide anchor sites for active Fe, while the abundant chain-like graphene act as connectors between ZSM-5 and the layered graphene, offering ample opportunities for TEA and its intermediates to contact the catalyst surface. This increases the number of active sites on the catalyst, thereby enhancing the catalytic performance of FexOy-N-ZSM-5. Notably, due to the interaction between FeOx and FeNx species, FexOy-N-ZSM-5 exhibits excellent thermal stability and water resistance, demonstrating promising potential for practical.

Back Cover: Tuning the Electronic Structures of Anchor Sites to Achieve Zero‐Valence Single‐Atom Catalysts for Advanced Hydrogenation

Back Cover: Tuning the Electronic Structures of Anchor Sites to Achieve Zero‐Valence Single‐Atom Catalysts for Advanced Hydrogenation

Back Cover: Tuning the Electronic Structures of Anchor Sites to Achieve Zero‐Valence Single‐Atom Catalysts for Advanced Hydrogenation

Back Cover: Tuning the Electronic Structures of Anchor Sites to Achieve Zero‐Valence Single‐Atom Catalysts for Advanced Hydrogenation

Fabrication of covalently bonded MoS2–graphene heterostructures with different organic linkers

Achieving stable and reliable 2D-2D van der Waals heterostructures remains challenging. The broadest strategy for synthesizing these heterostructures is growth or manually stacking one material on top of the other, yet it is inefficient. Here, we present a strategy for synthesizing covalently bonded MoS2-graphene heterostructures using organic linkers with two anchor sites at a low cost. Our covalent heterostructures exhibit a more homogeneously alternating structure than the corresponding randomly alternating structure of vdW heterostructures, as confirmed by surface-enhanced Raman spectroscopy (SERS) measurements. Moreover, different linkers can be used to adjust the interlayer distance between graphene and MoS2, leading to significant impacts on their optical and electrochemical properties, including Photoluminescence (PL), cyclic voltammetry (CV), Ultraviolet-visible spectroscopy (UV-Vis), and SERS. Our strategy offers opportunities to advance fundamental research and enable the practical application of 2D/2D van der Waals heterostructures in various fields, including optoelectronics, energy storage, and catalysis.

B and N Codoped Cellulose-Supported Ag-/Bi-Doped Mo(S,O)3 Trimetallic Sulfo-Oxide Catalyst for Photocatalytic H2 Evolution Reaction and 4-Nitrophenol Reduction.

Cellulose plays a significant role in designing efficient and stable cellulose-based metallic catalysts, owing to its surface functionalities. Its hydroxyl groups are used as anchor sites for the nucleation and growth of metallic nanoparticles and, as a result, improve the stability and catalytic activity. Meanwhile, cellulose is also amenable to surface modifications to be more suitable for incorporating and stabilizing metallic nanoparticles. Herein, the Ag-/Bi-doped Mo(S,O)3 trimetallic sulfo-oxide anchored on B and N codoped cellulose (B-N-C) synthesized by a facile approach showed excellent stability and catalytic activity for PHER at 573.28 μmol/h H2 with 25 mg of catalyst under visible light, and 92.3% of the 4-nitrophenol (4-NP) reduction was achieved within 135 min by in situ-generated protons. In addition to B and N codoping, our use of the calcination method for B-N-C preparation further increases the structural disorders and defects, which act as anchoring sites for Ag-/Bi-doped Mo(S,O)3 nanoparticles. The Ag-/Bi-doped Mo(S,O)3@B-N-C surface active site also stimulates H2O molecule adsorption and activation kinetics and reduces the photogenerated charge carrier's recombination rate. The Mo4+ → Mo6+ electron hopping transport and the O 2p and Bi 6s orbital overlap facilitate the fast electron transfer by enhancing the electron's lifetime and photoinduced charge carrier mobility, respectively. In addition to acting as a support, B-N-C provides a highly conductive network that enhances charge transport, and the relocated electron in B-N-C activates the H2O molecule, which enables Ag-/Bi-doped Mo(S,O)3@B-N-C to have appreciable PHER performance.

Asymmetrical anchor way of manganese atoms on carbon domain edge for enhanced oxygen reduction reaction

Single atomic catalysts (SACs), especially the catalysts featured by well-developed M-N4 moieties, show excellent catalytic activity and spark enormous attention. However, the highly symmetric active sites may result in some degenerate electronic states for the d orbitals of the center metal atom, which suffer from the unsatisfactory adsorption-desorption behaviors during reaction. Herein, we develop an asymmetric anchor site by two types of nitrogen (sp-N and pyridinic N) created in the inherent edge-rich carbon domain of hydrogen-substituted graphdiyne (HsGDY), where atomic catalyst like manganese atoms can be asymmetrically anchored on the one side of hexagon carbon rings. The abundant elegant hexagon carbon rings on HsGDY not only facilitate the creation of edge sites, but also provide available space for the coordination of terminal ligands (OH) with Mn atoms. The as-synthesized Mn-N-HsGDY exhibits excellent ORR activity and an impressive long-term cyclability for over 3800 cycles in a rechargeable Zn-air battery.

Tuning the Electronic Structures of Anchor Sites to Achieve Zero‐Valence Single‐Atom Catalysts for Advanced Hydrogenation

Single‐atom catalysts (SACs) have recently become highly attractive for selective hydrogenation reactions owing to their remarkably high selectivity. However, compared to their nanoparticle counterparts, atomically dispersed metal atoms in SACs often show inferior activity and are prone to aggregate under reaction conditions. Here, by theoretical calculations, we show that tuning the local electronic structures of metal anchor sites on g‐C3N4 by doping B atoms (BCN) with relatively lower electronegativity allows achieving zero‐valence Pd SACs with reinforced metal‐support orbital hybridizations for high stability and upshifted Pd 4d orbitals for high activity in H2 activation. The precise synthesis of Pd SACs on BCN supports with varied B contents substantiated the theoretical prediction. A zero‐valence Pd1/BCN SAC was achieved on a BCN support with a relatively low B content. It exhibited much higher stability in a H2 reducing environment, and more strikingly, a hydrogenation activity, approximately 10 and 34 times greater than those high‐valence Pd1/g‐C3N4 and Pd1/BCN with a high B content, respectively.

Tuning the Electronic Structures of Anchor Sites to Achieve Zero-Valence Single-Atom Catalysts for Advanced Hydrogenation.

Single-atom catalysts (SACs) have recently become highly attractive for selective hydrogenation reactions owing to their remarkably high selectivity. However, compared to their nanoparticle counterparts, atomically dispersed metal atoms in SACs often show inferior activity and are prone to aggregate under reaction conditions. Here, by theoretical calculations, we show that tuning the local electronic structures of metal anchor sites on g-C3N4 by doping B atoms (BCN) with relatively lower electronegativity allows achieving zero-valence Pd SACs with reinforced metal-support orbital hybridizations for high stability and upshifted Pd 4d orbitals for high activity in H2 activation. The precise synthesis of Pd SACs on BCN supports with varied B contents substantiated the theoretical prediction. A zero-valence Pd1/BCN SAC was achieved on a BCN support with a relatively low B content. It exhibited much higher stability in a H2 reducing environment, and more strikingly, a hydrogenation activity, approximately 10 and 34 times greater than those high-valence Pd1/g-C3N4 and Pd1/BCN with a high B content, respectively.

Green construction of self-floating polysaccharide-based hydrogels with catalytic activity for efficient organic pollutants reduction

This study employed an anionic heteropolysaccharide extracted from overgrown Enteromorpha and homopolysaccharide pullulan to fabricate a self-floating hydrogel by introducing bubble templates. Subsequently, green in-situ reduction and immobilization of silver nanoparticles (Ag NPs) in the hydrogel were successfully achieved without additional reducing agents. The heteropolysaccharide from Enteromorpha provides carboxyl and sulfate groups for Ag+ ions complexation, which is beneficial for the in-situ reduction of Ag NPs and inhibits their aggregation. The incorporation of bubble templates facilitates the creation of a hierarchical pore structure in the hydrogel, giving it self-floating properties for easy recycling, while the hierarchical network with rich anchor sites ensuring adequate traction for Ag NPs dispersion and stabilization. By adjusting polysaccharide content and using bubble templates, Ag NPs smaller than 10 nm can be obtained. The composite hydrogel exhibits tunable catalytic activity and excellent degradation towards Rhodamine B, Methyl Orange, and 4-Nitrophenol, with the normalized rate constant (knor) of 78.89, 59.08, and 30.42 min−1 g−1, respectively. Notably, the reduction efficiency remained above 98 % after 6 recycles with little leaching of Ag NPs, benefiting from its self-floating ability for easy recovery in practical applications.

Surface-enhanced Raman scattering spectroscopy monitoring and degradation of organic pollutants using a novel nanowire

A multifunctional Ag/AlOOH nanowires (ANW) composite substrate was constructed, which not only accomplishes highly sensitive detection of organic dye molecules, but also has excellent performance in the degradation of pollutants. The ANW in the Ag/ANW substrate possesses a high aspect ratio, which extends the distribution area of Ag and enables a large number of hot spots on the active substrate. Additionally, due to the abundant OH groups on the ANW, there is an increased number of anchor sites for adsorbed metal ions in the Ag/ANW compound, thus contributing to the enhancement and degradation of molecules. Moreover, the constructed multifunctional Ag/ANW nanocomplexes also show great promise for practical applications, providing a reference for the detection and degradation of contaminants.

Carbene Footprinting Directs Design of Genetically Encoded Proximity-Reactive Protein Binders.

Genetically encoding proximal-reactive unnatural amino acids (PrUaas), such as fluorosulfate-l-tyrosine (FSY), into natural proteins of interest (POI) confer the POI with the ability to covalently bind to its interacting proteins (IPs). The PrUaa-incorporated POIs hold promise for blocking undesirable POI-IP interactions. Selecting appropriate PrUaa anchor sites is crucial, but it remains challenging with the current methodology, which heavily relies on crystallography to identify the proximal residues between the POIs and the IPs for the PrUaa anchorage. To address the challenge, here, we propose a footprinting-directed genetically encoded covalent binder (footprinting-GECB) approach. This approach employs carbene footprinting, a structural mass spectrometry (MS) technique that quantifies the extent of labeling of the POI following the addition of its IP, and thus identifies the responsive residues. By genetically encoding PrUaa into these responsive sites, POI variants with covalent bonding ability to its IP can be produced without the need for crystallography. Using the POI-IP model, KRAS/RAF1, we showed that engineering FSY at the footprint-assigned KRAS residue resulted in a KRAS variant that can bind irreversibly to RAF1. Additionally, we inserted FSY at the responsive residue in RAF1 upon footprinting the oncogenic KRASG12D/RAF1, which lacks crystal structure, and generated a covalent binder to KRASG12D. Together, we demonstrated that by adopting carbene footprinting to direct PrUaa anchorage, we can greatly expand the opportunities for designing covalent protein binders for PPIs without relying on crystallography. This holds promise for creating effective PPI inhibitors and supports both fundamental research and biotherapeutics development.

Exploring Enhanced Hydrolytic Dehydrogenation of Ammonia Borane with Porous Graphene-Supported Platinum Catalysts.

Graphene is a good support for immobilizing catalysts, due to its large theoretical specific surface area and high electric conductivity. Solid chemical converted graphene, in a form with multiple layers, decreases the practical specific surface area. Building pores in graphene can increase specific surface area and provide anchor sites for catalysts. In this study, we have prepared porous graphene (PG) via the process of equilibrium precipitation followed by carbothermal reduction of ZnO. During the equilibrium precipitation process, hydrolyzed N,N-dimethylformamide sluggishly generates hydroxyl groups which transform Zn2+ into amorphous ZnO nanodots anchored on reduced graphene oxide. After carbothermal reduction of zinc oxide, micropores are formed in PG. When the Zn2+ feeding amount is 0.12 mmol, the average size of the Pt nanoparticles on PG in the catalyst is 7.25 nm. The resulting Pt/PG exhibited the highest turnover frequency of 511.6 min-1 for ammonia borane hydrolysis, which is 2.43 times that for Pt on graphene without the addition of Zn2+. Therefore, PG treated via equilibrium precipitation and subsequent carbothermal reduction can serve as an effective support for the catalytic hydrolysis of ammonia borane.

Defect engineering and metal confinement on titanium dioxide enhances SO2/H2O tolerance in NOx reduction: Oxygen and metal vacancies

A desirable catalyst with excellent SO2/H2O tolerance at low temperatures is of great significance for NOx removal from actual flue gas. Defect engineering and metal confinement on metal oxide surfaces have emerged as effective strategies to enhance catalyst selectivity and activity. Herein, a Mn-based catalyst (CeCoMn/TiO2) with metal and oxygen vacancies was constructed by high-energy ball milling. The catalyst exhibited superior SO2/H2O tolerance stability (70.8 %) at 180 ℃ and 40000 h−1 than that prepared by the impregnation method (43.5 %). Metal vacancies can serve as anchor sites to generate well-dispersed active centers, and oxygen vacancies facilitate gas-phase oxygen replenishment and electron transfer. The synergistic effect of metal vacancies and oxygen vacancies improved the activity of the catalyst. In-situ infrared and theoretical calculations reveal that the reaction mechanism follows the Langmuir-Hinshelwood pathway. The catalyst prepared by ball milling has better SO2/H2O tolerance due to stronger acidity and interaction. The synergistic effect of dual-defect found in this study may guide the development of superior anti-poisoning catalysts.

Proximal Tibia Fracture Through Suture Augmentation Sites Following ACL/MCL Repairs: A Case Report.

A 35-year-old man sustained a proximal tibia fracture from a low-energy mechanism 1 year after anterior cruciate and medial collateral ligament repairs with suture augmentation (SA). The fracture propagated through both tibial SA anchor sites. Following intramedullary tibial nailing, he returned to his prior level of function. While complications of SA for ligamentous procedures are rare, these techniques are being implemented more frequently and the full complication profile is yet to be determined. Our report documents a new complication and potential risk factors that surgeons should consider when performing SA for multiligament knee surgery in active individuals.

In situ growth of ZIF-8 on nanofibrous membrane for long-term ultra-high flux coalescence separation of oil-in-water emulsion

The presence of oil-in-water (O/W) emulsions poses a serious threat to the equilibrium of aquatic ecosystems, contaminates potable water resources, and disrupts the structure of soil layers. Consequently, there is an urgent need for effective and economically viable methods for removing emulsified oil droplets from water. The coalescence method has been proposed as an effective means of separating O/W emulsions. In this study, we developed an in situ growth strategy to decorate zeolitic imidazolate framework-8 (ZIF-8) on electrospun polyacrylonitrile (PAN) nanofibers for coalescence separation. The in situ growth process commenced with pretreatment to activate the PAN membrane, creating anchor sites for zinc ions, which was followed by immersion in precursors of ZIF-8 particles. The incorporation of ZIF-8 enhanced amphiphilicity, and roughness, and imparted a positive charge to the membrane, which was anticipated to effectively demulsify and coalesce oil droplets with a negative charge. The ZIF-8/PAN nanofiber membrane obtained a separation ratio exceeding 99.9 % for surfactant-free emulsions and 97.1 % for surfactant-stabilized emulsions. It also demonstrated an ultra-high permeation flux of 21,177 L m−2 h−1 and 14,118 L m−2 h−1, respectively, in a long-term continuous separation process.

(141) Surgical Outcomes of Infrapubic Insertion of the Inflatable Penile Prosthesis in 175 Transmen After Phalloplasty

Abstract Introduction Historically, inflatable penile prostheses (IPP) insertion in a neophallus has an estimated 40-50% surgical revision rate. Objective To review the surgical outcomes of a single center’s experience with the infrapubic approach to insertion of the IPP after phalloplasty in transmen. Methods The infrapubic prosthesis insertion after phalloplasty (IPIP) technique involves a horizontal incision anterior to the pubic symphysis, which allows dissection of the neophallus channel, the Space of Retzius, and the scrotal pocket. Surgical outcomes using the Titan (Coloplast, Minneapolis, MN) IPP by a single surgeon (MLC) were analyzed between October 2017 and June 2023. Complications were reviewed and categorized into erosions, infections, device malposition and malfunction, and less common events like necrosis and urinary tract injury. Results The IPIP technique was performed on 175 phalloplasty patients by a single surgeon (MLC): 156 patients had a prior RF phalloplasty, and 19 had a prior ALT phalloplasty. The mean followup was 32.8 months. Surgical revision was required in 35 patients (20%). There were 10 pump erosions through the neoscrotum, 1 glans erosion, 9 infections, 6 pump malpositions in the neoscrotum, 6 cylinder malposition in the neophallus, 3 mechanical malfunctions with broken tubing, 2 urethral injuries, 2 bladder injuries, and 1 glans necrosis. There were no instances of implant detachment from the pubic bone anchor site, osteomyelitis, nor total phallus loss. Conclusions Data for the IPIP technique using the commercially available Coloplast Titan IPP suggest a reduction in neophallus prosthetic surgical revision rates compared to previous reports. Longer term studies with patient reported outcomes are required for further evaluation. Disclosure Any of the authors act as a consultant, employee or shareholder of an industry for: Coloplast, Boston Scientific.

Synergistic Effect of Ion Doping and Type-II Heterojunction Construction and Ciprofloxacin Degradation by MIL-68(In,Bi)-NH2@BiOBr under Visible Light.

Heterojunction structure and ion doping techniques are viable tactics in facilitating the generation and separation of photogenerated electrons and holes in photocatalysis. In the current study, a novel Bi ion-doped MIL-68(In,Bi)-NH2@BiOBr (MIBN@BOB) type-II heterojunction was first synthesized in a one-step solvothermal reaction. Doping of Bi ions not only broadened the light-sensing range but also provided reliable anchor sites for the in situ growth of BiOBr. Meanwhile, the heterostructure supplied new channels for photogenerated carriers, accelerating the transfer and inhibiting the recombination of photogenerated electron-hole. The obtained MIBN@BOB exhibited enhanced photocatalytic performance (91.1%) than MIL-68(In)-NH2 (40.8%) and BiOBr (57.5%) in ciprofloxacin (CIP) degradation under visible light, with excellent reusability. Photocatalysts were characterized in detail, and a series of photoelectrochemical tests were utilized to analyze the photoelectric properties. MIBN@BOB were deduced to conform the electron conduction mechanism of conventional type-II heterojunctions. More importantly, based on the above experiments and density functional theory (DFT) calculation, BiOBr-Bi in MIBN@BOB can serve as the major active sites of CIP enrichment, and •O2- and 1O2 generated at the BiOBr interface can react with the adsorbed CIP directly. Lastly, the possible degradation products and pathways of CIP were analyzed by liquid chromatography-tandem mass spectrometry (LC/MS/MS). This study provides a reference for the construction of ion-doping-modified metal-organic framework (MOF)-based heterojunction photocatalysts and their application in antibiotic removal.