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Ultrafine RuMo particles on N, P co-doped hollow carbon functioned as a superior HOR electrocatalyst. Impressively, this catalyst exhibits a greatly enhanced mass activity and stability owing to the tuned d band structure of Ru.

Stable PdCoH nanosheets for efficient EOR were designed by introducing oxophilic metal cobalt and interstitial hydrogen into the Pd lattice. The synergistic effect of Co and H atoms boosts EOR performance with high CO tolerance and C1 selectivity.

Owing to their unique electromagnetic properties and structure anisotropy, two-dimensional (2D) magnetic metal flakes are attracting special attention for applications as microwave absorption materials. However, the conductive network formed by the connected metal flakes may lead to impedance mismatching and reduced performance. In this study, a facile and rational strategy was developed to fabricate yolk-shell-structured 2D flaky Fe/void/C composites by using α-Fe

High-entropy alloys (HEAs) have been attracting extensive research interests in designing advanced nanomaterials, while their precise control is still in the infancy stage. Herein, we have reported a well-defined PtBiPbNiCo hexagonal nanoplates (HEA HPs) as high-performance electrocatalysts. Structure analysis decodes that the HEA HP is constructed with PtBiPb medium-entropy core and PtBiNiCo high-entropy shell. Significantly, the HEA HPs can reach the specific and mass activities of 27.2 mA cm

The catalytic activation of CO2 is a crucial process in CO2 recycling for both fundamental research and industrial applications. Fe-based catalysts have been demonstrated to be highly active for th...

Summary FAPbI3 (FA+ = formamidinium) perovskite, one of the most efficient basic components in nowadays perovskite solar cells (PCSs), undergoes spontaneous phase transition while molecular-level investigations are still lacking. Here, we report a structural study on the phase transition process of the FA-based perovskites based on isolation and identification of a series of single crystal intermediates. A key intermediate of 8H phase with unique structure is discovered, which helps elucidate the complete phase evolution and stabilization mechanism of FA-based perovskites. Our new insight based on the Pauling’s rules not only deepens the understanding of the phase stabilization roles of cations and anions in maximizing the concentrations of corner-sharing halogens and cubic cages but also forms suggestion for fabrication of high-performance and long-term stable PCSs by controlling the factors such as composition, precursor solution, stoichiometry, and additives.

Water oxidation is one of the most challenging steps in CO

Atomically dispersed oxide-on-metal inverse nanocatalysts provide a blueprint to amplify the strong oxide-metal interactions for heterocatalysis but remain a grand challenge in fabrication. Here we report a 2D inverse nanocatalyst, RuOx -on-Pd nanosheets, by in situ creating atomically dispersed RuOx /Pd interfaces densely on ultrathin Pd nanosheets via a one-pot synthesis. The product displays unexpected performance toward the oxygen reduction reaction (ORR) in alkaline medium, which represents 8.0- and 22.4-fold enhancement in mass activity compared to the state-of-the-art Pt/C and Pd/C catalysts, respectively, showcasing an excellent Pt-alternative cathode electrocatalyst for fuel cells and metal-air batteries. Density functional theory calculations validate that the RuOx /Pd interface can accumulate partial charge from the 2D Pd host and subtly change the adsorption configuration of O2 to facilitate the O-O bond cleavage. Meanwhile, the d-band center of Pd nanosubstrates is effectively downshifted, realizing weakened oxygen binding strength.

Concave morphologies provide noble metal nanocrystals (NCs) with unique performances due to large specific surface areas, high curves, hot spots, and elevated energy facets. As a result, concave morphologies have attracted considerable attention in many areas. However, most NCs with concave shapes are currently made of a single metal, leaving plenty of room for easy wet chemical synthesis and structural analysis of unique concave structures, especially bimetallic compounds. In this work, concave octahedral Pt–Pd alloy NCs with high-index {hhl} faces were synthesized using glycine as a coordination molecule and polyvinylpyrrolidone as the surfactant and reducing agent. The high-index facets coupled with the synergistic and electronic effects between Pt and Pd provided concave octahedral Pt–Pd alloy NCs with excellent activity and stability toward the electrooxidation of formic acid when compared to their convex counterparts and commercial Pt black.

Engineering the composition and structure of Pt-based alloy electrocatalysts has exhibited great promise for enhancing activity and durability in the oxygen reduction reaction (ORR) and methanol oxidation reaction (MOR). However, it remains a great challenge to completely achieve this goal because of sluggish kinetics and surface CO poisoning. Herein, we successfully constructed trimetallic PtNiCo branched nanocages via a simple etching treatment. The trimetallic PtNiCo nanocages exhibited outstanding activity and durability in both acidic ORR and MOR. Strikingly, the mass activity of the catalyst in ORR and MOR reached 1.03 A mgPt−1 and 2.82 A mgPt−1, with 13.8- and 5.6-times enhancement of specific activity compared to Pt/C. Detailed investigations reveal that the most optimized electronic structure for the d-band center (a 0.17 eV downshift compared to pure Pt) by the alloying effect of Co and Ni contributed to the enhanced performances and great CO-tolerance of such unique Pt-based catalysts, which provide a new perspective for designing high-performance electrocatalysts for commercial fuel cells.

Composites of ferromagnetic metal and carbon with hierarchical structures are favoured for strengthening microwave absorption capability due to the synergistic effects of hybrid structures and enhanced interfacial polarization. However, it remains a great challenge to fabricate composites with desirable structures due to the collapse of the design structure following post-treatment. Herein, a facile strategy was developed to synthesize micrometre-sized hollow rod-like hierarchical structures assembled by CoFe/C nanosheets via using MgO micrometre rods as a sacrificial template. The morphology of the primary unit and the loading amount of carbon can be tailored by controlling the reaction conditions, both of which play important roles in improving the microwave absorption performance. The optimized CoFe/C hierarchical composite shows excellent microwave absorption performance. With a matching thickness of 2.15 mm, the strongest reflection loss (RL) reaches up to −40.5 dB at 9.1 GHz, while the effective absorption (RL

Pd-based electrocatalysts are considered to be a promising alternative to Pt in anion-exchange membrane fuel cells (AEMFCs), although major challenges remain. Most of the Pd-based electrocatalysts developed for the sluggish oxygen reduction reaction (ORR) have been exclusively evaluated by rotating disk electrode (RDE) voltammetry at room temperature, rather than in membrane electrode assemblies (MEAs), making it challenging to apply them in practical fuel cells. We have developed a series of carbon-supported novel PdH

Dual-active-sites atomically coupled on ultrafine 1D nanowires (NWs) can offer synergic atomic heterojunctions (AHJs) and high atomic-utilization toward multipurpose and superior catalysis. Here, ≈2-nm-thick PtIr/IrO

On-road information, including road boundaries, road markings, and road cracks, provides significant guidance or warning to all road users. Recently, the on-road information extraction from LiDAR data have been widely studied. However, for the LiDAR data with lower accuracy and higher noise, some detailed information, such as road boundary, is difficult to be extracted correctly. Furthermore, most of previous studies lack an exploration of efficiently extracting multiple on-road information from a single framework. In this paper, we propose a new framework that can simultaneously extract multiple on-road information from high accuracy LiDAR data and can also more robustly extract detailed road boundaries from low accuracy LiDAR data. First, we propose a Curb-Aware Ground Filter to extract ground points with rich curb structure features. Second, we transform the vertical density, elevation gradient and intensity features of the ground points into multiple feature maps and extract multiple on-road information from the feature maps by employing a semantic segmentation network. Experimental results on three datasets with different data accuracy demonstrate that our method outperforms other recent competitive methods.

Direct epoxidation of propylene by molecular oxygen alone is one of the "dream reactions" in heterogeneous catalysis. Despite much effort, the yield of propylene epoxide is still too low to be commercially attractive due to the trade-off between conversion and selectivity. Here, we demonstrate that doping Cl into the lattice of Cu2O nanocrystals by the intergrowth method not only can enhance the catalytic selectivity and conversion of direct propylene epoxidation but also can solve the long-existing Cl loss problem. In particular, Cl-doped rhombic dodecahedral Cu2O with (110) exposing facets exhibited 63% PO selectivity with a 12.0 h-1 turnover frequency at 200 °C, outperforming any other coinage metal-based catalysts under mild conditions. Comprehensive characterization and theoretical calculations revealed that the Cl-decorated Cu(I) facilitated formation of electrophilic oxygen species, thus boosting the production of propylene oxide. This work provides a general strategy to develop catalysts and explore the promoter effect by creating uniform isolated anion doping to activate a nearby metal center by virtue of well-defined nanocrystals.

Many important chemical transformations enabled by plasmonic hot carrier photocatalysis have been reported, although their efficiencies are often too low for practical applications. We examine how the efficiency of plasmon-induced hot electron transfer depends on the Au particle size in Au-tipped CdS nanorods. We show that with decreasing Au size, the plasmon width increases due to enhanced surface damping contributions. The excitation of Au nanoparticles leads to an instrument response time-limited ultrafast hot electron transfer process to CdS (≪140 fs). The quantum efficiency of this process increases from ∼1% to ∼18% as the particle size decreases from 5.5 ± 1.1 to 1.6 ± 0.5 nm due to both enhanced hot electron generation and transfer efficiencies in small Au particles. Our finding suggests that decreasing plasmonic particle size is an effective approach for improving plasmon-induced hot carrier transfer efficiency and provides important insight for the rational improvement of plasmonic hot carrier-based devices.

Recently, great efforts have been devoted to improving the catalytic activity and durability of Pt based catalysts for proton exchange membrane fuel cells. Here, surfactant-free PtAg fractal dendritic nanocrystals (NCs) with high surface area were prepared via a facile one-pot reaction. The control synthetic experiments proved that the formation of PtAg fractal dendritic NCs resulted from a kinetics-controlled growth, i.e. the “diffusion limited aggregation” mechanism. Due to their unique structural advantage and clean surface, the as-prepared PtAg fractal dendritic NCs exhibited superior electrochemical catalytic activities and structural stabilities compared with commercial Pt black and Pt/C towards methanol electro-oxidation and oxygen reduction reaction in acidic media. The design strategy presented here may be useful in fabricating other highly active and stable Pt–M catalysts for fuel cells.

In this study, a porous hybrid catalyst with carbon-confined Ni2P porous nanosheet arrays supported on nickel foam (Ni2P@C NAs/NF) was developed via a one-step phosphorization of NiMOF precursor. Remarkably, the as-fabricated Ni2P@C NAs/NF exhibited superior oxygen evolution reaction (OER) performance and only required a small overpotential of 243 mV to deliver a current density of 15 mA cm−2, which surpassed most reported noble-metal-free based OER catalysts working in alkaline media. Such striking results could be ascribed to the synergistic effect between the interconnected macroporous structure (facilitating mass transport and exposing rich accessible catalytic centers) and the modulated electronic states induced by electron transfer from the carbon matrix to nickel phosphide (optimizing its intrinsic electrocatalytic property). In particular, the alkaline two-electrode water electrolyser, which was assembled by simultaneously utilizing Ni2P@C NAs/NF as the cathode and anode, showed considerable water-splitting activity and durability. Additionally, systematic post-electrolysis structural study confirmed the in situ formation of a γ-NiOOH film on the Ni2P surface at the anode. This work provides a deep insight into the post-electrolysis structure of nickel-containing catalyst materials and would be helpful for the design of three-dimensional porous hybrid nanocatalysts.

Platinum (Pt)-based catalysts have shown excellent catalytic performance in many fields, particularly for the oxygen reduction reaction (ORR) and direct oxidation of small fuel molecules. Further development of Pt-based electrocatalysts relies on the morphology design of Pt-based alloy nanocrystals (NCs) with highly accessible and active surface sites to optimize Pt atomic utilization. In this work, we reported PtCo-excavated rhombic dodecahedral (ERD) NCs consisting of the self-assembly of 24 ultrathin nanosheets synthesized by a simple wet chemical method. The morphology can be regulated from convex to excavated polyhedra by controlling the amount of formaldehyde and the molar ratio of the Co/Pt precursor. The as-prepared PtCo ERD NCs/C catalyst exhibits excellent ORR performance, which has about 12 times higher specific activity and 6 times higher mass activity than the commercial Pt/C catalyst. It also displays good electrocatalytic ability towards methanol oxidation, in which the specific activity and mass activity are about 6 times higher and 2 times higher than the commercial Pt/C, respectively. Their enhanced activity is attributed to the excavated structure and alloy feature.

Preventing the stacking of two-dimensional (2D) structured nanomaterials is important for developing high-performance gas sensors. To address this challenge, three-dimensional (3D) hollowed-out hierarchical Fe2O3 microrods assembled by nanosheets were successfully fabricated via a facile MgO-mediated chemical template conversion strategy. Structurally, the large active surface area of the microrods significantly enhanced gas adsorption, thereby resulting in a high response. Additionally, the hollow interior and the well-aligned porous structure between adjacent nanosheets were favorable for the rapid diffusion of detected gases, reducing the response/recovery times. Gas sensing measurements revealed that the nanosheet-assembled, hollowed-out hierarchical γ-Fe2O3 microrods calcined at 300 °C (i.e., Fe2O3-300) exhibited the best performance among the as-prepared samples with different phases. Strikingly, the sensitivity to 100 ppm acetone at 220 °C reached 125.5, and the response/recovery times were only 0.9/15 s, respectively. Compared to α-Fe2O3 obtained at 500 °C (i.e., Fe2O3-500), Fe2O3-300 with the γ-phase exhibits superior capacity to chemisorb oxygen and the bulk resistance effect, which are intrinsically beneficial for enhancing its gas sensing performance. In addition, the as-synthesized nanosheet-assembled, hollowed-out hierarchical γ-Fe2O3 microrods exhibited outstanding repeatability and remarkable long-term stability, which suggests their potential application in fabricating highly sensitive gas sensors. This work provides a viable approach for synthesizing various nanosheet-assembled, hollowed-out hierarchical metal oxides.

An alternative way to mitigate the energy and environmental crisis is electrochemical CO2 reduction (ECR) into high-value products using renewable energy. Recently, Sn-based catalysts have attracted attention because of their high ECR selectivity to C1 products (HCOOH and CO). However, high overpotential, low current density, and poor stability are some issues that need to be addressed for these Sn based ECR catalysts. Resolving these problems largely depends on a comprehensive insight into the relationship between the structure and the performance of the catalysts in the ECR. In this work, we specifically compared the ECR activities and selectivities of three kinds of SnO2 nanocrystals (NCs) with different dominantly exposed facets ({111}, {221} and {110}) in an effort to elucidate their surface structure–performance relationship. We found that {111} faceted octahedral SnO2 NCs (i.e., Oct-{111} NPs) showed not only high selectivity for C1 products (>90% FE) in a wide potential range of −0.7 V to −1.0 V but also significant stability. The performance of Oct-{111} NPs was superior to that of the other two SnO2 morphologies, i.e. {221} faceted SnO2 octahedral NCs and {110}-dominantly faceted SnO2 rod-like NCs. Detailed structure and composition analysis revealed that such different ECR performances of the three SnO2 facets were mainly related to the formation of different catalytic layers on their surfaces. The findings presented here will deepen our understanding of the surface-dependent performances of Sn-based electrocatalysts in the ECR. This work provides a new strategy to construct high performance electrocatalysts through rational regulation of the metal/oxide interface.

Designable bimetallic core–shell nanoparticles exhibit superb performance in many fields including industrial catalysis, energy conversion and chemical sensing, due to their outstanding properties associated with their tunable electronic structure. Herein, Au–Pd core–shell (AurichPd@AuPdrich) nanowires (NWs) were synthesized through a one-pot facile chemical reduction method in the presence of cetyltrimethyl ammonium bromide (CTAB) surfactant. The thickness of the Pd shell could be adjusted by directly controlling the Au/Pd feeding ratio while maintaining the nanowire morphology. The as-obtained Au75Pd25 core–shell NWs with a thin Pdrich shell showed significantly enhanced activities towards the reduction of hydrogen peroxide with the sensitivity reaching 338 μA cm−2 mM−1 and a linear range up to 10 mM. In sum, Pd shell thickness could be used to adjust the electronic structure, thereby optimizing the catalytic activity.

Magnetic particle/carbon hybrid structures are promising candidates for high performance microwave absorbing materials with light weight and strong absorption. However, it remains a great challenge to balance the permittivity and permeability to realize impedance matching and further improve their absorption bandwidth. Herein, an effective strategy is designed to fabricate sandwich-like Co15Fe85@C/RGO composites. By introducing RGO sheets in the hybrid structures, the electromagnetic parameters, impedance matching and microwave absorption properties of the final materials can be well controlled. The optimized Co15Fe85@C/RGO composite shows an excellent microwave absorption performance, the strongest reflection loss (RL) of the sample is up to −33.38 dB at 10.72 GHz with a matching thickness of 2.5 mm, and the effective bandwidth (RL < −10 dB) can reach 9.2 GHz (8.64–17.84 GHz). With a single thickness, such a wide absorption band is rarely reported. Their excellent performance can be ascribed to the synergetic effect of the chemical composition and unique sandwich-like structures, which will improve impendence matching and strong microwave attenuation constants of the composites. Our results provide a facile strategy for tuning the electromagnetic parameters and microwave absorption properties of magnetic metal/carbon hybrid structures.

In the last two decades, metal-organic frameworks (MOFs), as a class of porous crystalline materials formed by organic linkers coordinated-metal ions, have attracted increasing attention due to their unique structures and wide applications. Compared to single components, various well-designed MOF-based composites combining MOFs with other functional materials, such as nanoparticles, quantum dots, natural enzymes and polymers with remarkably enhanced or novel properties have recently been reported. To efficiently and directionally synthesize high-performance MOF-based composites for specific applications, it is vital to understand the structural-functional relationships and role of MOFs. In this review, preparation methods of MOF-based composites are first summarized and then the relationship between the structure and performance is determined. The functions of MOFs in practical use are classified and discussed through various examples, which may help chemists to understand the structural-functional relationship in MOF-based composites from a new perspective.

Ethanol is a promising liquid clean energy source in the energy conversion field. However, the self-poisoning caused by the strongly adsorbed reaction intermediates (typically, CO) is a critical problem in ethanol oxidation reaction. To address this issue, we proposed a joint use of two strategies, alloying of Pt with other metals and building Pt/metal-oxide interfaces, to achieve high-performance electrocatalytic ethanol oxidation. For this, a well-designed synthetic route combining wet impregnation with a two-step thermal treatment process was established to construct PtSn/SnO x interfaces on carbon nanotubes. Using this route, the alloying of Pt-Sn and formation of PtSn-SnO x interfaces can simultaneously be achieved, and the coverage of SnO x thin films on PtSn alloy nanoparticles can be facilely tuned by the strong interaction between Pt and SnO x . The results revealed that the partial coverage of SnO x species not only retained the active sites, but also enhanced the CO anti-poisoning ability of the catalyst. Consequently, the H-PtSn/SnO x /CNT-2 catalyst with an optimized PtSn-SnO x interface showed significantly improved performances toward the ethanol oxidation reaction (825 mA mg Pt -1 ). This study provides deep insights into the structure-performance relationship of PtSn/metal oxide composite catalysts, which would be helpful for the future design and fabrication of high-performance Pt-based ethanol oxidation reaction catalysts.

Research of detection of low molecular weight compounds on human health and biological systems become increasingly important. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), a soft ionization equipment, is a rapid, reliable, high-sensitivity, high-throughput and simple test instrument. However, the application of MALDI-TOF MS in the analysis of small molecules (500 Da) has become a great challenge because of the interference from the conventional matrices in low mass region when using conventional matrices. In this research, tricobalt tetraoxide (Co

Concave morphologies provide noble metal nanocrystals (NCs) with unique performances due to large specific surface areas, high curves, hot spots, and elevated energy facets. As a result, concave morphologies have attracted considerable attention in many areas. However, most NCs with concave shapes are currently made of a single metal, leaving plenty of room for easy wet chemical synthesis and structural analysis of unique concave structures, especially bimetallic compounds. In this work, concave octahedral Pt-Pd alloy NCs with high-index {

Recently, metal-organic framework (MOF)-based multienzyme systems integrating different functional natural enzymes and/or nanomaterial-based artificial enzymes are attracting increasing attention due to their high catalytic efficiency and promising application in sensing. Simple and controllable integration of enzymes or nanozymes within MOFs is crucial for achieving efficient cascade catalysis and high stability. Here, we report a facile electrochemical assisted biomimetic mineralization strategy to prepare an artificial multienzyme system for efficient electrochemical detection of biomolecules. By using the GOx@Cu-MOF/copper foam (GOx@Cu-MOF/CF) architecture as a proof of concept, efficient enzyme immobilization and cascade catalysis were achieved by in situ encapsulation of glucose oxidase (GOx) within MOFs layer grown on three-dimensional (3D) porous conducting CF via a facile one-step electrochemical assisted biomimetic mineralization strategy. Due to the bio-electrocatalytic cascade reaction mechanism, this well-designed GOx@Cu-MOF modified electrode exhibited superior catalytic activity and thermal stability for glucose sensing. Notably, the activity of GOx@Cu-MOF/CF still remained at ca. 80% after being incubated at 80 °C. In sharp contrast, the activity of the unprotected electrode was reduced to the original 10% after the same treatment. The design strategy presented here may be useful in fabricating highly stable enzyme@MOF composites applied for efficient photothermal therapy and other platform under high temperature.

The synthesis of nanocrystals (NCs) with defined morphology and surface structure provides an effective way to investigate the structure-activity relationship of nanocatalytsts, and it will facilitate the design of nanocatalysts with excellent catalytic performance. In this paper, we developed a facile method to synthesize PdH0.43 NCs with the shape of cube, octahedron and rhombic dodecahedron (RD), whose surface facets are {100}, {111} and {110}, respectively. The as-prepared PdH0.43 NCs are highly stable and exhibit enhanced catalytic activity and extremely low overpotential towards electro-oxidation of formic acid compared with the commercial Pd black and three types of Pd NCs. The specific activity of the cubic PdH0.43 NCs is more than five times that of the commercial Pd black and two times that of the cubic Pd NCs. Among the three types of PdH0.43 NCs with different surface structure, the activity order is followed by PdH0.43 {100} > PdH0.43 {111} > PdH0.43 {110}.

The catalytic conversion of ethane to high value-added chemicals is significantly important for utilization of hydrocarbon resources. However, it is a great challenge due to the typically required high temperature (> 400 °C) conditions. Herein, a highly active catalytic conversion process of ethane at room temperature (25 °C) is reported on single iron atoms confined in graphene via the porphyrin-like N4-coordination structures. Combining with the operando time of flight mass spectrometer and density functional theory calculations, the reaction is identified as a radical mechanism, in which the C–H bonds of the same C atom are preferentially and sequentially activated, generating the value-added C2 chemicals, simultaneously avoiding the over-oxidation of the products to CO2. The in-situ formed O–FeN4–O structure at the single iron atom serves as the active center for the reaction and facilitates the formation of ethyl radicals. This work deepens the understanding of alkane C–H activation on the FeN4 center and provides the reference in development of efficient catalyst for selective oxidation of light alkane.