Regioselective super-assembly of Prussian blue analogue.

The construction of high-asymmetrical structures demonstrates significant potential in improving the functionality and distinctness of nanomaterials, but remains a considerable challenge. Herein, we develop a one-pot method to fabricate regioselective super-assembly of Prussian blue analogue (PBA) -- a PBA anisotropic structure (PBA-AS) decorated with epitaxial modules--using a step-by-step epitaxial growth on a rapidly self-assembled cubic substrate guided by thiocyanuric acid (TCA) molecules. The epitaxial growth units manifest as diverse geometric shapes, which are predominantly concentrated on the {100}, {111}, or {100}+{111} crystal plane of the cubic substrate.

Rapid Construction of Double Crystalline Prussian Blue Analogue Hetero-Superstructure.

The controllable construction of complex metal-organic coordination polymers (CPs) merits untold scientific and technological potential, yet remains a grand challenge of one-step construction and modulating simultaneously valence states of metals and topological morphology. Here, a thiocyanuric acid (TCA)-triggered strategy is presented to one-step rapid synthesis a double-crystalline Prussian blue analogue hetero-superstructure (PBA-hs) that comprises a Co[Fe(CN)] cube overcoated with a KCo[Fe(CN)] shell, followed by eight self-assembled small cubes on vertices. Unlike common directing surfactants, TCA not only acts as a trigger for the fast growth of KCo[Fe(CN)] on the Co[Fe(CN)] phase resulting in a PBA-on-PBA hetero-superstructure, but also serves as a flange-like bridge between them.

Dipole Effect on Oxygen Evolution Reaction of 2D Janus Single-Atom Catalysts: A Case of Rh Anchored on the 62-NP Configurations.

Catalytic performance of single-atom catalysts (SACs) relies fundamentally on the electronic nature and local coordination environment of the active site. Here, based on a machine-learning (ML)-aided density functional theory (DFT) method, we reveal that the intrinsic dipole in Janus materials has a significant impact on the catalytic activity of SACs, using 2D γ-phosphorus carbide (γ-PC) as a model system. Specifically, a local dipole around the active site is a key degree to tune the catalytic activity and can be used as an important descriptor with a high feature importance of 17.

Synergistic effect of composition gradient and morphology on the catalytic activity of amorphous FeCoNi-LDH.

The rational design of electrocatalysts with well-designed compositions and structures for the oxygen evolution reaction (OER) is promising and challenging. Herein, we developed a novel strategy - a one-step double-cation etching sedimentation equilibrium strategy - to synthesize amorphous hollow Fe-Co-Ni layered double hydroxide nanocages with an outer surface of vertically interconnected ultrathin nanosheets (Fe-Co-Ni-LDH), which primarily depends on the etching sedimentation equilibrium of the template interface. This unique vertical nanosheet-shell hierarchical nanostructure possesses enhanced charge transfer, increased active sites, and favorable kinetics during electrolysis, resulting in superb electrocatalytic performance for the oxygen evolution reaction (OER).

Oxygen Defect Engineering Promotes Synergy Between Adsorbate Evolution and Single Lattice Oxygen Mechanisms of OER in Transition Metal-Based (oxy)Hydroxide.

The oxygen evolution reaction (OER) activity of transition metal (TM)-based (oxy)hydroxide is dominated by the number and nature of surface active sites, which are generally considered to be TM atoms occupying less than half of surface sites, with most being inactive oxygen atoms. Herein, based on an in situ competing growth strategy of bimetallic ions and OH ions, a facile one-step method is proposed to modulate oxygen defects in NiFe-layered double hydroxide (NiFe-LDH)/FeOOH heterostructure, which may trigger the single lattice oxygen mechanism (sLOM). Interestingly, by only varying the addition of H O , one can simultaneously regulate the concentration of oxygen defects, the valence of metal sites, and the ratio of components.

A General Strategy for Synthesis of Binary Transition Metal Phosphides Hollow Sandwich Heterostructures.

The hollow sandwich core-shell micro-nanomaterials are widely used in materials, chemistry, and medicine, but their fabrication, particularly for transition metal phosphides (TMPs), remains a great challenge. Herein, a general synthesis strategy is presented for binary TMPs hollow sandwich heterostructures with vertically interconnected nanosheets on the inside and outside surfaces of polyhedron FeCoP /C, demonstrated by a variety of transition metals (including Co, Fe, Cd, Mn, Cu, Cr, and Ni). Density functional theory (DFT) calculation reveals the process and universal mechanism of layered double hydroxide (LDH) growth on Prussian blue analog (PBA) surface in detail for the first time, which provides the theoretical foundations for feasibility and rationality of the synthesis strategy.

Directional Charge Transfer Channels in a Monolithically Integrated Electrode for Photoassisted Overall Water Splitting.

Photoelectrocatalytic performance of a system is fundamentally determined by the full absorption of sunlight and high utilization of photoexcited carriers, but efficiency of the latter is largely limited by inefficient charge transfer from the absorber to reactive sites. Here, we propose to construct directional charge transfer channels in a monolithically integrated electrode, taking carbon dots/carbon nitride (CCN) nanotubes and FeOOH/FeCo layered double hydroxide (FFC) nanosheets as a representative, to boost the photoassisted overall water splitting performance. Detailed experimental investigations and DFT calculations demonstrate that the interfacial C-O-Fe bonds between CCN and FFC act as charge transfer channels, facilitating the directional migration of the photogenerated carriers between CCN and FFC surfaces.

Application of the hospital-family holistic care model in caregivers of patients with permanent enterostomy: A randomized controlled trial.

Aims: To evaluate the effectiveness of the hospital-family holistic care model based on the theory of 'Timing It Right' in caregivers of patients with permanent enterostomy.

Design: A prospective randomized controlled trial.

Methods: One hundred and twenty-five caregivers of patients with permanent enterostomy were recruited from 1 May 2017-31 August 2019.

Strain and Electric Field Controllable Schottky Barriers and Contact Types in Graphene-MoTe van der Waals Heterostructure.

Two-dimensional (2D) transition metal dichalcogenides with intrinsically passivated surfaces are promising candidates for ultrathin optoelectronic devices that their performance is strongly affected by the contact with the metallic electrodes. Herein, first-principle calculations are used to construct and investigate the electronic and interfacial properties of 2D MoTe in contact with a graphene electrode by taking full advantage of them. The obtained results reveal that the electronic properties of graphene and MoTe layers are well preserved in heterostructures due to the weak van der Waals interlayer interaction, and the Fermi level moves toward the conduction band minimum of MoTe layer thus forming an n type Schottky contact at the interface.

Type-II/type-II band alignment to boost spatial charge separation: a case study of g-CN quantum dots/a-TiO/r-TiO for highly efficient photocatalytic hydrogen and oxygen evolution.

Efficient spatial charge separation and transfer that are critical factors for solar energy conversion primarily depend on the energetic alignment of the band edges at interfaces in heterojunctions. Herein, we first report that constructing a 0D/0D type-II(T-II)/T-II heterojunction is an effective strategy to ingeniously achieve long-range charge separation by taking a ternary heterojunction of TiO2 and graphitic carbon nitride (g-C3N4) as a proof-of-concept. Incorporating g-C3N4 quantum dots (QCN), as the third component, into the commercial P25 composed of anatase (a-TiO2) and rutile (r-TiO2) can be realized via simply mixing the commercially available Degussa P25 and QCN solution followed by heat treatment.

Hierarchical Self-assembly of Well-Defined Louver-Like P-Doped Carbon Nitride Nanowire Arrays with Highly Efficient Hydrogen Evolution.

Self-assembled nanostructure arrays integrating the advantages of the intrinsic characters of nanostructure as well as the array stability are appealing in advanced materials. However, the precise bottom-up synthesis of nanostructure arrays without templates or substrates is quite challenging because of the general occurrence of homogeneous nucleation and the difficult manipulation of noncovalent interactions. Herein, we first report the precisely manipulated synthesis of well-defined louver-like P-doped carbon nitride nanowire arrays (L-PCN) via a supramolecular self-assembly method by regulating the noncovalent interactions through hydrogen bond.

Organic Small Molecule Activates Transition Metal Foam for Efficient Oxygen Evolution Reaction.

Developing low-cost, highly efficient, and durable electrocatalysts for oxygen evolution reaction (OER) is essential for the practical application of electrochemical water splitting. Herein, it is discovered that organic small molecule (hexabromobenzene, HBB) can activate commercial transition metal (Ni, Fe, and NiFe) foam by directly evolving metal nanomeshes embedded in graphene-like films (M-NM@G) through a facile Br-induced solid-phase migration process. Systematic investigations indicate that HBB can conformally generate graphene-like network on bulk metal foam substrate via the cleavage of CBr bonds and the formation of CC linkage.

Effects of hospital-family holistic care model on the health outcome of patients with permanent enterostomy based on the theory of 'Timing It Right'.

Aims And Objectives: To explore the effects of hospital-family holistic care model based on 'Timing It Right' on the health outcome of patients with permanent colostomy.

Background: Colorectal cancer is a common malignant tumour of digestive system, which seriously threatens human life and health. Colostomy is one of the main treatments for colorectal cancer, which effectively improves the 5-year survival rate of patients.

Interfacial charge modulation: carbon quantum dot implanted carbon nitride double-deck nanoframes for robust visible-light photocatalytic tetracycline degradation.

Steering charge kinetics at the interface is essential to improve the photocatalytic performance of two-dimensional (2D) material-based heterostructures. Herein, we developed a novel strategy-simultaneously building two kinds of heterojunctions- to modulate interfacial charge kinetics in polymeric carbon nitride (CN) for improving the photocatalytic activity. Using a simple one-step thermal condensation of carbon quantum dot (CQD)-contained supramolecular precursors formed in water, the controllable CQD embedded CN nanoframes possessed two kinds of heterogeneous interfaces within seamlessly stitched micro-area two-dimensional in-plane and out-of-plane domains.

A design rule for two-dimensional van der Waals heterostructures with unconventional band alignments.

The energetic alignment of band edges at the interface plays a central role in determining the properties and applications of two-dimensional (2D) van der Waals (vdW) heterostructures. Generally, three conventional heterojunction types (type-I, type-II, and type-III) have widely been investigated and used in diverse fields. Unconventional band alignments (type-IV, type-V, and type-VI) are, however, hitherto unreported in the vdW heterostructures.

Penta-Graphene as a Potential Gas Sensor for NO Detection.

Two-dimensional (2D) penta-graphene (PG) with unique properties that can even outperform graphene is attracting extensive attention because of its promising application in nanoelectronics. Herein, we investigate the electronic and transport properties of monolayer PG with typical small gas molecules, such as CO, CO, NH, NO and NO, to explore the sensing capabilities of this monolayer by using first-principles and non-equilibrium Green's function (NEGF) calculations. The optimal position and mode of adsorbed molecules are determined, and the important role of charge transfer in adsorption stability and the influence of chemical bond formation on the electronic structure of the adsorption system are explored.

Strategy to boost catalytic activity of polymeric carbon nitride: synergistic effect of controllable in situ surface engineering and morphology.

Polymeric carbon nitride (CN) is a promising metal-free catalyst plagued by a low intrinsic activity. Herein, a novel strategy based on controllable in situ surface engineering and morphology was developed to synergistically boost the catalytic activity of CN by tuning the hydroxyl groups on its surface and constructing a unique nanostructure. The controllable introduction of hydroxyl groups on CN nanoshells, prepared by the thermal condensation of oxygen-containing supramolecular precursors formed in water, led to spatial separation of the HOMO and LUMO, and effective exciton dissociation, as verified by experiments and ab initio calculations.

Monolayer Phosphorene-Carbon Nanotube Heterostructures for Photocatalysis: Analysis by Density Functional Theory.

One-dimensional (1D)/2D heterostructures have attracted great attention in electronic and optoelectronic fields because of their unique geometrical structures and rich physics. Here, we systematically explore electronic structure and optical performance of single-wall carbon nanotube (CNT)/phosphorene (BP) hybrids by large-scale density functional theory (DFT) computation. The results show that the interfacial interaction between CNT and BP is a weak van der Waals (vdW) force and correlates with tube diameter of CNTs.

Doping-Induced Hydrogen-Bond Engineering in Polymeric Carbon Nitride To Significantly Boost the Photocatalytic H Evolution Performance.

Unlike graphene, graphitic carbon nitride (CN) polymer contains a weak hydrogen bond and van der Waals (vdWs) interactions besides a strong covalent bond, which controls its final morphology and functionality. Herein, we propose a novel strategy, hydrogen-bond engineering, to tune hydrogen bonds in polymeric CN through nonmetal codoping. Incorporation of B and P dopants breaks partial hydrogen bonds within the layers and simultaneously weakens the vdWs interaction between neighboring layers, resulting in ultrathin codoped CN nanosheets.

Doping-induced enhancement of crystallinity in polymeric carbon nitride nanosheets to improve their visible-light photocatalytic activity.

Structural defects can greatly inhibit electron transfer in two-dimensional (2D) layered polymeric carbon nitride (CN) unit, seriously lowering its utilization ratio of photogenerated charges during photocatalysis. Herein, we propose a new strategy based on intra-melon hydrogen bonding interactions in 2D CN frameworks to improve the crystallinity of CN. This concept was validated by removing some amino groups and connecting melon using codoped B and F atoms via a simple one-step sodium fluoroborate-assisted thermal treatment.

Substrate-induced magnetism and topological phase transition in silicene.

Silicene has shown great potential for applications as a versatile material in nanoelectronics and is particularly promising as a building block for spintronic applications. Unfortunately, despite its intriguing properties, such as a relatively large spin-orbit interaction, one of the greatest obstacles to the use of silicene as a host material in spintronics is its lack of magnetism or a topological phase transition owing to the silicene-substrate interaction, which influences its fundamental properties and has yet to be fully investigated. Here, we show that when silicene is grown on a CeO2 substrate, an appreciable robust magnetic moment appears in silicene covalently bonded to CeO2 (111), while a topological phase transition from a topological insulator to a band insulator occurs regardless of van der Waals (vdW) interactions or covalent bonding interactions at the interface.

Mesoporous g-C₃N₄ Nanosheets: Synthesis, Superior Adsorption Capacity and Photocatalytic Activity.

Elimination of pollutants from water is one of the greatest challenges in resolving global environmental issues. Herein, we report a high-surface-area mesoporous g-C3N4 nanosheet with remarkable high adsorption capacity and photocatalytic performance, which is prepared through directly polycondensation of urea followed by a consecutive one-step thermal exfoliation strategy. This one-pot method to prepare mesoporous g-C3N4 nanosheet is facile and rapid in comparison with others.

Interfacial Interactions in Monolayer and Few-Layer SnS/CH NH PbI Perovskite van der Waals Heterostructures and Their Effects on Electronic and Optical Properties.

A high light-absorption coefficient and long-range hot-carrier transport of hybrid organic-inorganic perovskites give huge potential to their composites in solar energy conversion and environmental protection. Understanding interfacial interactions and their effects are paramount for designing perovskite-based heterostructures with desirable properties. Herein, we systematically investigated the interfacial interactions in monolayer and few-layer SnS/CH NH PbI heterostructures and their effects on the electronic and optical properties of these structures by density functional theory.

Simultaneous covalent and noncovalent carbon nanotube/AgPO hybrids: new insights into the origin of enhanced visible light photocatalytic performance.

Understanding the interfacial interaction is of paramount importance for rationally designing carbon nanomaterial-based hybrids with optimal performance for electronics, optoelectronics, sensing, advanced energy conversion and storage. Here, we firstly reveal that both covalent and noncovalent interactions simultaneously exist in carbon nanotube (CNT)/AgPO hybrids by studying systematically the electronic and optical properties to elucidate the mechanism of their enhanced photocatalytic performance. Metallic CNT(9,0) may chemically or physically interact with the AgPO(100) surface depending on its relative orientations, whereas semiconducting CNT(10,0) can only noncovalently functionalize AgPO.

Insights into enhanced visible-light photocatalytic activity of C modified g-CN hybrids: the role of nitrogen.

Recent experiments have shown that the photocatalytic activity of g-CN can be greatly enhanced by C modification, however, a fundamental understanding of its mechanistic operation is still lacking. Using first-principles calculations, the interfacial effects of C/g-CN nanocomposites on the electronic properties, charge transfer and optical response have been explored in detail. For different stacking patterns, the two constituents are always linked by van der Waals (vdW) forces without any exception, and form type-II heterojunctions in most cases.