RuPx nanoparticles (NPs) encapsulated in uniform N,P‐codoped hollow carbon nanospheres (RuPx@NPC) have been synthesized through a facile route in which aniline–pyrrole copolymer nanospheres are used ...to disperse Ru ions followed by a gas phosphorization process. The as‐prepared RuPx@NPC exhibits a uniform core–shell hollow nanospherical structure with RuPx NPs as the core and N,P‐codoped carbon (NPC) as the shell. This strategy integrates many advantages of hollow nanostructures, which provide a conductive substrate and the doping of a nonmetal element. At high temperatures, the obtained thin NPC shell can not only protect the highly active phase of RuPx NPs from aggregation and corrosion in the electrolyte but also allows variation in the electronic structures to improve the charge‐transfer rate greatly by N,P codoping. The optimized RuPx@NPC sample at 900 °C exhibits a Pt‐like performance for the hydrogen evolution reaction (HER) and long‐term durability in acidic, alkaline, and neutral solutions. The reaction requires a small overpotential of only 51, 74, and 110 mV at 10 mA cm−2 in 0.5 m H2SO4, 1.0 m KOH, and 1.0 m phosphate‐buffered saline, respectively. This work provides a new way to design unique phosphide‐doped carbon heterostructures through an inorganic–organic hybrid method as excellent electrocatalysts for HER.
Get your coat on: RuPx nanoparticles encapsulated in uniform N,P‐codoped hollow carbon nanospheres (RuPx@NPC) are synthesized by a facile route in which a aniline–pyrrole copolymer nanospheres are used to disperse Ru ions followed by a gas phosphorization process.
In acidic media, benchmark electrocatalysts for oxygen evolution reaction (OER) are mainly restricted to noble metal oxides like IrO2 and RuO2. Herein, a facile electrodeposition-hydrothermal process ...has been used to fabricate mesoporous Ag-doped Co3O4 nanowire arrays supported on FTO (AgCo/FTO) for water oxidation in 0.5 M H2SO4. The role of electrodeposited Ag includes: 1) Ag film on FTO can direct the vertical growth of Co3O4 to form nanowire arrays; 2) Ag2O in AgCo hydroxides precursors contribute to the formation of mesoporous nanostructure owing to the pyrolysis of Ag2O in calcination process. XRD confirms the diffraction peaks of metal Ag and Co3O4. SEM and TEM images display that mesoporous nanowire arrays of Ag-doped Co3O4 are uniformly distributed on FTO, which introduces more exposed active sites and shorter electron transfer paths. AgCo/FTO show excellent OER activity with the onset potential of 1.91 V at the current density of 10 mA cm−2. Besides, AgCo/FTO shows high stability at a constant overpotential of 370 mV for 10 h. So Ag-doping greatly enhances not only the conductivity but also the stability of electrocatalyst in acidic media. Therefore, Ag-doped transition metal oxides may be promising alternative mesoporous nanostructures for efficient OER in acid.
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•Mesoporous Ag-doped Co3O4 nanowire arrays supported on FTO have been synthesized.•Ag film is helpful for vertical growth and mesoporous structure of AgCo nanowire.•Ag-doped Co3O4 nanowires show excellent OER activity and stability in 0.5 M H2SO4.•Ag-doped transition metal oxides may be promising precursors for efficient OER.
A significant requirement for a bone implant is to let bone cells grow better. However, how to increase the cellular activity of the scaffold at a certain elastic modulus remains unclear. Here, we ...developed a method to derive the relationship between design parameters, porosity, and mechanical properties of uniform structures for pore functionally graded scaffolds (PFGS) design. PFGS is a combination of different uniform structures by matching design parameters. Ti6Al4V PFGS and uniform structures with sizes of 10 × 10 × 12 mm were designed and fabricated via selective laser melting (SLM). The mechanical properties and cell proliferation of these structures were investigated. Results indicated that the mathematical model of elastic modulus, yield strength and porosity can accurately predict the mechanical properties of structures. For PFGS, cell proliferation rate from day 4 to day 7 was 140%, while for the uniform structures were only 90%. The results demonstrated that PFGS is more suitable for bone tissue implantation.
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•Mathematical models were developed to calculate elastic modulus, yield strength and porosity of uniform structures.•A novel approach for the design of pore functionally graded scaffolds suitable for bone engineering application is proposed.•The strain-stress curves of pore functionally graded scaffold are as same as that of the uniform structures.•Cell proliferation rate is significantly higher for pore functionally graded scaffold, in comparison to the uniform scaffold.
Buried interface modification can effectively improve the compatibility between interfaces. Given the distinct interface selections in perovskite solar cells (PSCs), the applicability of a singular ...modification material remains limited. Consequently, in response to this challenge, we devised a tailored molecular strategy based on the electronic effects of specific functional groups. Therefore, we prepared three distinct silane coupling agents, and due to the varying inductive effects of these functional groups, the electronic distribution and molecular dipole moments of the coupling agents are correspondingly altered. Among them, trimethoxy (3,3,3‐trifluoropropyl)‐silane (F3‐TMOS), which possesses electron‐withdrawing groups, generates a molecular dipole moment directed toward the hole transport layer (HTL). This approach changes the work function of the HTL, optimizes the energy level alignment, reduces the open‐circuit voltage loss, and facilitates carrier transport. Furthermore, through the buffering effect of the coupling agent, the interface strain and lattice distortion caused by annealing the perovskite are reduced, enhancing the stability of the tin‐based perovskite. Encouragingly, tin PSCs treated with F3‐TMOS achieved a champion efficiency of 14.67 %. This strategy provides an expedient avenue for the design of buried interface modification materials, enabling precise molecular adjustments in accordance with distinct interfacial contexts to ameliorate mismatched energetics and enhance carrier dynamics.
In this study, we introduce trimethoxy (3,3,3‐trifluoropropyl)‐silane (F3‐TMOS) with molecular dipole moment pointing towards the hole transport layer as the buried interface modification material, which not only optimizes energy level alignment and carrier dynamics but also relieves interface strain and reduces lattice distortion, resulting in a champion power conversion efficiency (PCE) of 14.67 %.
Metal halide perovskites are ideal candidates for indoor photovoltaics (IPVs) because of their easy‐to‐adjust bandgaps, which can be designed to cover the spectrum of any artificial light source. ...However, the serious non‐radiative carrier recombination under low light illumination restrains the application of perovskite‐based IPVs (PIPVs). Herein, polar molecules of amino naphthalene sulfonates are employed to functionalize the TiO2 substrate, anchoring the CsPbI3 perovskite crystal grains with a strong ion–dipole interaction between the molecule‐level polar interlayer and the ionic perovskite film. The resulting high‐quality CsPbI3 films with the merit of defect‐immunity and large shunt resistance under low light conditions enable the corresponding PIPVs with an indoor power conversion efficiency of up to 41.2% (Pin: 334.11 µW cm−2, Pout: 137.66 µW cm−2) under illumination from a commonly used indoor light‐emitting diode light source (2956 K, 1062 lux). Furthermore, the device also achieves efficiencies of 29.45% (Pout: 9.80 µW cm−2) and 32.54% (Pout: 54.34 µW cm−2) at 106 (Pin: 33.84 µW cm−2) and 522 lux (Pin: 168.21 µW cm−2), respectively.
The amino naphthalene sulfonates (ANS) molecules are incorporated as a dipolar interlayer at the buried interface to fabricate CsPbI3 perovskite indoor photovoltaics (PIPVs). The strong ion–dipole interaction between polar ANS molecules and ionic perovskites enables the target PIPVs to deliver a record indoor PCE of up to 41.2% (Pout:137.66 µW cm−2) under a standard LED light source (2956 K, 1062 lux).
Abstract Two-dimensional transition metal dichalcogenides, particularly MoS2 nanosheets, have been deemed as a novel category of NIR photothermal transducing agent. Herein, an efficient and versatile ...one-pot solvothermal synthesis based on “bottom-up” strategy has been, for the first time, proposed for the controlled synthesis of PEGylated MoS2 nanosheets by using a novel “integrated” precursor containing both Mo and S elements. This facile but unique PEG-mediated solvothermal procedure endowed MoS2 nanosheets with controlled size, increased crystallinity and excellent colloidal stability. The photothermal performance of nanosheets was optimized via modulating the particulate size and surface PEGylation. PEGylated MoS2 nanosheets with desired photothermal conversion performance and excellent colloidal and photothermal stability were further utilized for highly efficient photothermal therapy of cancer in a tumor-bearing mouse xenograft. Without showing observable in vitro and in vivo hemolysis, coagulation and toxicity, the optimized MoS2 -PEG nanosheets showed promising in vitro and in vivo anti-cancer efficacy.
Tin‐based perovskite solar cells (TPSCs) have attracted significant research interest due to their exceptional optoelectronic properties and environmentally friendly characteristics. However, TPSCs ...with ideal bandgap suffer from substantial current losses, necessitating the development of innovative interface engineering strategies to enhance device performance. In this study, an unprecedented approach constructing charge transfer path is presented by a simple post‐growth treatment of 3‐Aminomethylbenzobthiophene (3‐AMBTh) on the perovskite film. The selective reaction of 3‐AMBTh with exposed FA+ on the perovskite surface suppresses the formation of iodine vacancy defects, leading to a reduction in trap density. Additionally, the residual aromatic rings on the surface form an effective π–π stacking interaction system with subsequently deposited ICBA, facilitating enhanced charge transfer at the interface. By harnessing the potential of the charge transfer path, the TPSCs exhibit remarkable device efficiency of up to 14.53%, positioning them among the top‐performing TPSCs reported to date.
A novel constructing charge bridge path strategy is proposed to enhance charge extraction and interface contact at the interface of perovskite layer and electron transport layer in response to the severe current loss problem in tin‐based photovoltaics. After the post‐treatment of 3‐AMBTh, the current density of the device is further improved, thereby increasing the efficiency of tin‐based photovoltaics to 14.53%, which is also one of the best‐performing devices in tin‐based perovskite field.
Unreacted/excess lead iodide is considered to be the archcriminal for the rapid degradation of hybrid perovskite solar cells. Meanwhile, a high‐quality perovskite film with uniform and large grain ...size is the basis for high‐performance perovskite modules. Herein, a dual‐site molecular additive 4‐Aniline Sulfonic Acid (4A) is developed to regulate the unreacted/excess PbI2 and passivate defects through hydrogen bonding and intermolecular interactions between amino, and a sulfate groups and PbI2, respectively. Furthermore, the introduction of the 4A additive can induce perovskite seeds to grow uniformly on the substrate, yielding dense, uniform and defect‐less perovskite films with large grain sizes. This enables the fabrication of perovskite photovoltaics with a maximum power conversion efficiency of 24.09% (0.09 cm2) and 20.87% (16 cm2), respectively. This work demonstrated a new strategy to deposit high‐quality large‐scale perovskite films for photovoltaic modules.
Aniline sulfonic acid with dual sites is utilized to cure excess/unreacted lead iodide in perovskite films. The introduction of additives can induce a uniform growth of perovskite seeds on the substrate, which aids the growth of high‐quality and uniform perovskite films. The fabricated perovskite photovoltaics deliver maximum power conversion efficiency of 24.09% (0.09 cm2) and 20.87% (16 cm2), respectively.
Defect states play an important role in the photovoltaic performance of metal halide perovskites. Particularly, the passivation of surface defects has made great contributions to high‐performance ...perovskite photovoltaics. This highlights the importance of understanding the surface defects from a fundamental level by developing more accurate and operando characterization techniques. Herein, a strategy to enable the surface carriers and photocurrent distributions on perovskite films to be visualized in the horizontal direction is put forward. The visual image of photocurrent distribution is realized by combining the static local distribution of carriers provided by scanning near‐field optical microscopy with the dynamic transporting of carriers achieved via a scanning photocurrent measurement system. Taking a surface passivated molecule as an example, a comprehensive defect scene including static and dynamic as well as local and entire conditions is obtained using this strategy. The comprehensive analysis of the trap states in perovskite films is pioneered vertically and horizontally, which will powerfully promote the deep understanding of defect mechanisms and carrier behavior for the goal of fabricating high‐performance perovskite optoelectronic devices.
A strategy which makes collected electrical signals visualized in form of mapping by a scanning photocurrent measurement system is proposed. The surface photocurrent distribution of perovskite films is visualized in the horizontal direction vividly. It provides a brand‐new viewpoint of in‐depth understanding on the surface defect states for developing high‐performance perovskite solar cells.
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