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The anti-Ramsey number A R (G , H) is the maximum number of colors in an edge-coloring of a graph in the family G without any rainbow copy of H. The anti-Ramsey number for matchings has been studied extensively in several graph families, while the problem for perfect matchings was only solved in complete graphs. The anti-Ramsey number of matchings in the family of regular bipartite graphs of order large enough was determined by Li and Xu. Jin improved their bounds on the order of 3-regular bipartite graphs. In this paper, we consider the problem for perfect matchings in 3-regular bipartite graphs. Let G be the family of 3-regular bipartite graphs with m vertices in each partite set. First, we characterize the structure of extremal graphs for the Turán number of perfect matchings in graphs with maximum degree three. Using this characterization, we show that A R (G , m K 2) = 3 m − 3. Moreover, we show that A R (F , m K 2) = 3 m − 5 , where F is the subfamily of 3-edge-connected graphs in G. In order to prove this result, we characterize the structure of bipartite graphs, which contains no perfect matchings, with maximum degree three and size Turán number minus one. [ABSTRACT FROM AUTHOR]

The better application of robot technology in space unstructured scenes has become an important research topic. How to adapt to limited workspace and maintain high reliability sampling activities on unstructured surfaces with unknown geometric information and physical features poses high requirements for the implementation of automated sampling missions for extraterrestrial celestial bodies (ECBs). This work introduces a biomimetic adhesion sampler PBAS. It expects to achieve multisite core sampling activities on the unstructured surface of ECBs under astronaut assistance or unmanned automatic operation. Different from previous sampler, the system adopts novel modular structure design and has made improvements to the bionic adhesion mechanism, percussive and drilling mechanism, power transmission and sensing mechanism, and control mechanism. PBAS can firmly adhere to unstructured surfaces and efficiently obtain complete coring samples through penetration and drilling activities. It is compact and lightweight and has high portability, good reusability, excellent efficiency, as well as better performance in automatic sampling operations. Finally, to verify the effectiveness and reliability of the PBAS, a testing apparatus was designed. Relevant tests were conducted outdoors and in the laboratory. The experimental results indicate that PBAS can successfully adhere to surfaces with different characteristics and obtain coring samples with a length exceeding 50 mm. • The operation mode and design criteria of the PBAS system are provided. • Design details and mechanism model are analyzed. • Relevant experimental platform and environment are introdudced. • Preliminary filed test results are presented. • Some discussion and conclusion remarks are made. [ABSTRACT FROM AUTHOR]

Highlights • The combining of label-free cell phenotypic assay with 2DLC. • D1 activity location and D2 activity tracking obtained three β 2 -AR agonists. • The first time to discover diarylheptanoids with the β 2 -AR agonistic activity. • Providing possible explanation for the anti-asthmatic effect of C. zedoaria. Abstract Traditional Chinese Medicines (TCMs) have been widely used in clinical practice, and provided a rich source for discovering new drug leads. However, efficient identification of active molecules responsible for the therapeutic effects of complex TCMs is still highly challenging. Here, we combined label-free cell phenotypic assay with two dimensional liquid chromatography (2DLC) to identify potential β 2 -adrenoceptor (β 2 -AR) agonists related to anti-asthmatic effect of Curcuma zedoaria Rosc (C.zedoaria), a commonly used TCM. The ethyl acetate extract of C.zedoaria was first fractionated into 26 fractions. Label-free cell phenotypic profiling was then used to locate the active sites. Orthogonal second-dimensional (D2) separation was performed on two fractions displaying agonistic effect at the β 2 -AR, combined with screening of the D2 fractions to track the activity. Finally, this approach led to the isolation of three known diarylheptanoids, among which diarylheptanoid b exhibited the most potent agonistic activity with an EC 50 value of 5.93 μM. This result was further demonstrated through the chemical synthesis of diarylheptanoid b. It is the first time to discover that diarylheptanoids could activate the β 2 -AR, which may be responsible for the anti-asthmatic effect of C.zedoaria observed traditionally and in clinical application. This study also demonstrates the potential of this integrated strategy for identifying active ingredients and determining the basis of therapeutic materials in complex TCMs. [ABSTRACT FROM AUTHOR]

A novel online comprehensive two-dimensional liquid chromatography (2DLC) coupled with quadrupole time-of-flight (Q-TOF) mass spectrometry (MS) method is developed for the analysis of Curcuma kwangsiensis ( C. kwangsiensis ) extract. In this system, a newly developed phenyl/tetrazole sulfoether (PTAS) bonded stationary phase was introduced to construct RPLC×RPLC combined with C18. The unique structure endowed PTAS with very different selectivity from C18, reaching a high orthogonality of 93.2%. Moreover, such a combination settled compatibility issues because of the weaker hydrophobic retaining property of PTAS, thus allowing direct interfacing in online configuration. As a result of coupling with the mass spectrometry, a four-dimensional (4D) data plot was presented, in which 439 peaks (containing positive mode and negative mode) were counted, and 105 compounds were grouped and tentatively identified in C. kwangsiensis extract, including 73 unreported ones. Some novel types of compounds with masses exceeding 500 were discovered for the first time. Besides, compared to one-dimensional liquid chromatography (1DLC), the great resolution power of this system allowed separation of more isomers. These results provide supplementary to the material basis of C. Kwangsiensis and in-depth research should be conducted. The configuration of RPLC×RPLC-Q-TOF MS can be a powerful and efficient tool for separation and characterization of chemical substances in complicated herbal extracts. [ABSTRACT FROM AUTHOR]

Sunlight-driven electrolytic splitting of water is a promising route to hydrogen production, and widespread implementation has called for the development of inexpensive, robust and large-scale electrodes. Here, nickel nanoparticles partially embedded into carbon fiber cloth (NiΦCFC) is prepared on a large scale (e.g., 40 cm × 40 cm) via a metal-mediated pitting process, which is adopted to fabricate hydrogen evolution reaction electrode for the first time. The partially embedded structure is beneficial for regulating the electron density state of carbon, exposing the nickel catalytic sites and improving the catalytic stability. The two kinds of electrochemical area and density functional theory results confirm that the interface effect between nickel and defective carbon leads into a low Gibbs free energy of H* adsorption. The NiΦCFC as flexible and efficient electrodes require a small overpotential of 131.5 mV to achieve −10 mA cm −2 . Note that the two-electrode electrolyzer composed of FeNi layered double hydroxide loaded on CFC (NiFe-LDH/CFC) (+)//NiΦCFC (−) possesses a voltage of 1.54 V at −10 mA cm −2 , which can also be powered by a solar cell. The facile and large-scale preparation of NiΦCFC as flexible electrodes could be adapted for the industrial hydrogen production powered by solar energy. [ABSTRACT FROM AUTHOR]

As one of the most important parts of deep space exploration missions, the sampling technologies of extraterrestrial celestial bodies (ECBs) have attracted the attention and interest of many researchers. As a relatively efficient and convenient sampling technique, drill samplers have been applied in different ECBs exploration missions. Different from the previous drill apparatus, this paper introduces a novel automatic assisted drill system (AADS), which is used to sample the deep layer regolith of ECBs. This drilling system can sample the deep regolith layer under manual assistance or unmanned automatic operation mode. The sampler has improved and designed a segmented detachable coring pipe, drilling pipe and casing pipe. It can largely maintain the layer information in the depth direction of the ECBs regolith and can also automatically change the drill sampling process through the driller change system to improve the sampling efficiency. Finally, an automatic test apparatus was designed, and an experimental platform was established to conduct a drill sampling test for the AADS sampler. The experimental results show that the AADS sampling system can successfully obtain at least 2.4 m depth and 1.1 kg weight simulated regolith samples. • The AADS design details are provided. • The AADS sampling strategy are analyzed. • An automatic test apparatus and experimental platform are introduced. • Preliminary filed test results are presented. [ABSTRACT FROM AUTHOR]

Advanced materials for electrocatalytic water splitting are central to renewable energy research. In this study, we describe a two-step reaction for preparing hydrogen evolution reaction (HER) electrodes composed of Pt nanoparticles and MoS 2 nanosheets grown on carbon fibers. The morphology and the structures are characterized by a variety of techniques including SEM, TEM, XRD and XPS. Detailed electrochemical characterizations demonstrate that the Pt nanoparticles/MoS 2 nanosheets/carbon fibers electrode (2.03 w% Pt) exhibited an excellent catalytic activity for HER in an acidic electrolyte with an overpotential of −5 mV (vs. HER). And the corresponding Tafel slope is estimated to be 53.6 mV/dec. Stability tests through long-term potential cycles and extended electrolysis confirm the exceptional durability of the catalyst. [ABSTRACT FROM AUTHOR]

Lunar rock sampling is an important means of studying the evolutionary history of planets. However, facing the special microgravity environment of the Moon, general rock sampling drills cannot provide the torque and pressure required for the mission. Therefore, it is of great significance to study the sampling drill with attachment function. In this study, the claw spines of insects were simulated, and a biomimetic spine laminated structure with flexible connections was designed. The working principle of attachment and detachment was analyzed using a rod model with elastic characteristics. The process of biomimetic spines attaching to rough surfaces was simulated using the coupling method of multi-body dynamics and discrete element analysis (MBD-DEM). The mechanical properties of bionic claws during attachment were analyzed. Mechanical experiments were conducted on biomimetic spines attached to volcanic rock. The experiment results for single and multiple spines were compared with the simulation results, verifying the accuracy and reliability of the simulation model. Finally, A bionic attachment prototype was designed and tested for performance. The attachment device was integrated into a sampling drill and drilling experiments were conducted. This article provides important reference for the optimization of biomimetic spine structures, along with adding value to the design of attachment equipment. [Display omitted] • Rubber constitutive model applied for dynamics modeling of spines. • MDB-DEM method used to simulate the working process of the spine attachment device. • Spine experiments were carried out and compared with simulations. [ABSTRACT FROM AUTHOR]

To realize high capacitance and long cycle performance of supercapacitors, hierarchical microflowers assembled from MoS 2 /polyaniline sandwiched nanosheets (MoS 2 /PANI SNSs) have been developed as electrode materials. In the hybrid nanosheets, PANI intercalates into the (002) interlayer of MoS 2 , leading to enhanced electron transfer as well as expanded interlayers which is beneficial for ion diffusion kinetics. Furthermore, the hierarchical microflower-like structure prevents aggregation of MoS 2 nanosheets, while the sandwich structure relieves the volume expansion and dissolution of PANI during repeated charge/discharge cycles. In the three-electrode test system for supercapacitors, the MoS 2 /PANI SNSs Exhibit 245.5 F g −1 at a 10 A g −1 in the first cycle, and retain 212.6 F g −1 after 16000 cycles. Assembled as symmetric supercapacitors in the two-electrode configuration, the MoS 2 /PANI SNSs show 81.3 F g −1 at 1 A g −1 in the first cycle, and retain 70.0 F g −1 after 8000 cycles. [ABSTRACT FROM AUTHOR]

The star-arrow docking ring is a ubiquitous structure on space vehicles and is often used as a feature component for pose measurement and capture in non-cooperative space capture missions. When the capture task is performed at a close distance of 0.5 m, due to the high radiation and high light intensity of the space and the coating of the satellite surface with thermal control multilayer materials, the lighting environment is complex, and the grayscale image processing is difficult. The point cloud grayscale image contour feature localization detection method converts the point cloud image into a grayscale image and then estimates the relative pose of the docking ring. Aiming at the problem of fast pose estimation in the case of relative motion, the algorithm adds a fast positioning module of frame image feature area based on the motion model on the original basis, which effectively reduces the feature retrieval area and improves the real-time performance of the algorithm. It is verified by physical simulation experiments. The results show that the method can effectively reduce the influence of stray light and eliminate noise contours. The pose estimation results of the docking ring are accurate and stable, the relative position calculation error is less than 1.5 mm, and the relative pose error is less than 0.45°. The frequency is better than 2 Hz, which meets the needs of real-time capture by space robotic arms. [ABSTRACT FROM AUTHOR]

The demand for efficient and cost-effective anode materials in microbial fuel cells (MFCs) provides the impetus to use carbon derived from solid waste to support bacterial growth and proliferation. Here we show that the municipal sludge-derived carbon (SC) with a porous structure and abundant surface functional groups is effective in improving performance of MFCs. The SC is coated on the 3-D graphite felt (GF) surface by pyrrole electropolymerization in order to increase the surface cites that are interacted with bacteria, resulting in the formation of PPy/SC-modified GF anode. The scanning electron microscopy analysis indicates that the PPy/SC-modified GF can substantially increase anode surface area. The X-ray photoelectron spectroscopy (XPS) results suggest that the PPy/SC-modified GF anode possesses higher surface N/C ratio and higher relative contents of O C–NH 2 and O C–O functional groups than other counterpart anodes. These characteristics are essential for increasing bacterial attachment to the anode surface, electron-transfer rate and thus anode performance and power performance. The maximum power density resulting from the PPy/SC-modified GF anode was 568.5 mW m −2 (13.6 W m −3 ) increased by 1.9, 2.7 and 3.5 times as compared to the PPy/AC-modified GF anode, the PPy alone-modified GF anode and the unmodified GF anode, respectively. [ABSTRACT FROM AUTHOR]

[Display omitted] • The Pt-O bond between Pt and TiO 2 enhances interfacial stability of Pt/TiO 2 /Ti. • Optimized interfacial electronic structure promotes an appropriate H adsorption. • The perfect encapsulation of TiO 2 prevents hydrogenation breakage of Ti substrate. • Pt/TiO 2 /Ti performs high and stable HER activity (η 10 = 23 mV, 180 mA cm−2 for 25 h). • Constructed acidic electrolyzer presents efficient water splitting performance. The development of efficient and stable integrated electrodes is crucial for the advancement of electrolyzer. Herein, the ultra-low platinum (12.7 μg Pt cm−2) anchored TiO 2 nano-polyhedrons protective titanium fibers paper (Pt/TiO 2 /Ti) is synthesized as an integrated electrode for gas diffusion, current collector and catalytic hydrogen production. The Pt/TiO 2 /Ti electrode exhibits remarkable activity (23 mV at 10 mA cm−2) and durability (180 mA cm−2 for 25 h) for hydrogen evolution reaction in acidic electrolyte, which is attributed to the enhanced interface via Pt-O bond between Pt and TiO 2. Specifically, the optimizing electronic structure of Pt anchoring on the TiO 2 enhances hydrogen adsorption energy to improve the intrinsic activity of HER. In addition, the relatively negative adsorption energy (E ads) of Pt atom on TiO 2 significantly contributes to the structural stability of the Pt/TiO 2 /Ti electrode. Moreover, the complete encapsulation of titanium fibers by TiO 2 layer enhances the structural stability of Pt/TiO 2 /Ti by preventing hydrogenation-induced breakage of the titanium substrate. The constructed electrolyzer of (−) Pt/TiO 2 /Ti || IrO 2 /TiO 2 /Ti (+) presents efficient water splitting performance (1.464 V at 10 mA cm−2) and long-term durability (∼100% retention for 30 h) in acidic electrolyte. This work highlights the importance of integrated electrodes and the feasibility of acidic electrolyzer. [ABSTRACT FROM AUTHOR]

Tetrahymena piriformis belongs to the ciliated protists (ciliates), causing severe economic losses in aquaculture. Chemical drugs currently used usually have toxic side effects, and there is no specific drug against Tetrahymena. Therefore, it is an urgent need to identify new antiparasitic lead compounds. In the present study, the in vitro parasiticidal activity of ethyl acetate (EtOAc) extracts and water extracts from 22 selected traditional Chinese medicines (TCMs) were evaluated against T. piriformis. The EtOAc extract of P. corylifolia turned out to be the most active with the minimum parasiticidal concentration of 100 mg/L within 3 h. Thus, it was separated into 12 fractions by the first-dimensional (D1) normal phase liquid chromatography (NPLC), meanwhile combining with in vitro antiparasitic tests for activity tracking. Subsequently, 8 flavonoids were identified in the active fractions by the second-dimensional (D2) reverse phase liquid chromatography (RPLC) tandem high-resolution mass spectrometry. According to the results, 5 flavonoids were selected for in vitro antiparasitic test, of which isobavachalcone showed the minimum parasiticidal concentration of 3.125 mg/L in 2 h. Bathing treatment of infected guppies with isobavachalcone could significantly reduce the burden of T. piriformis , obtaining a 24-h median effective concentration (24-h EC 50) value of 1.916 mg/L. And the concentration of isobavachalcone causing guppies to die within 24 h is 39 times than that of 24-h EC 50. The results demonstrated that isobavachalcone has the potential to be developed into a novel commercial fish drug against T. piriformis. [Display omitted] • The EtOAc extract of Psoralea corylifolia has activity against Tetrahymena piriformis. • Bavachinin A, Bavachin D, Corylifol A, Neobavaisoflavone and Isobavachalcone were identified. • The acute toxicity and anthelmintic effect of isobavachalcone on Poecilia reticulate were studied. [ABSTRACT FROM AUTHOR]

The nanoscale effect enables the unique magnetic, optical, thermal and electrical properties of nanostructured materials and has attracted extensive investigation for applications in catalysis, biomedicine, sensors, and energy storage and conversion. The widely used synthesis methods, such as traditional hydrothermal reaction and calcination, are bulk heating processes based on thermal radiation. Differing from traditional heating methods, non-thermal radiation heating technique is a local heating mode. In this regard, this review summarizes various non-thermal radiation heating methods for synthesis of nanomaterials, including microwave heating, induction heating, Joule heating, laser heating and electron beam heating. The advantages and disadvantages of these non-thermal radiation heating methods for the synthesis of nanomaterials are compared and discussed. Finally, the future development and challenges of non-thermal radiation heating method for potential synthesis of nanomaterials are discussed. [ABSTRACT FROM AUTHOR]

Hydrogen generation from plastics waste is a promising strategy to solve the plastic pollution crisis. Making full use of infrared energy of solar spectrum is an important subject for efficient solar photocatalysis. Herein, single-atom-layer Pt (SAL-Pt) clusters anchored on TiO 2−x /Ti was used as photothermal catalyst to generate hydrogen from plastic in liquid conditions. The confinement effect of laser-regulated oxygen vacancies in TiO 2−x /Ti plays an important role in anchoring SAL-Pt under mildly temperature and pressure condition. The obtained Pt/TiO 2−x /Ti possesses excellent photothermal catalytic hydrogen evolution performance from reforming plastic waste under infrared light (273.12 μmol cm−2 h−1). The enhanced photothermal activity of Pt/TiO 2−x /Ti is due to enhanced infrared light absorption via plasmonic effect and hot electron aggregation on SAL-Pt from TiO 2−x /Ti. The practical applicability is further verified by photothermal catalytic reforming plastics to H 2 under ambient sunlight irradiation, which possesses high performance (25.5 μmol cm−2 h−1) and stability (in consecutive week). [Display omitted] • TiO 2−x /Ti with oxygen vacancies were confirmed to atomically disperse metals through strong coordination interaction. • Single-atom-layer Pt clusters on TiO 2−x /Ti were formed with the maximum atom-utilization efficiency for catalysis. • Pt/TiO 2−x /Ti possessed excellent photothermal catalytic H 2 evolution performance from reforming plastic under IR. • An excellent catalytic performance and stability under ambient sunlight verified the practical applicability. [ABSTRACT FROM AUTHOR]

• Electrocatalytic reduction of nitrogen-containing pollutants to ammonia are reviewed. • Strategy to improve NO solubility and product separation of NH 3 are proposed. • Strategies to achieve high performance of NO 3 − reduction to NH 3 are presented. • Strategies to enhance the performance of NO 2 − reduction to NH 3 are displayed. Nitrogenous pollutants have caused serious environmental pollution, which endangers human life and ecological environment. The electrochemical nitrogenous pollutants reduction to ammonia driven by clean electric energy has been considered as an ideal technology for the recovery and utilization of nitrogenous pollutants. Unfortunately, the electrochemical reduction of nitrogenous pollutants has long been limited by low solubility, slow mass transfer, low partial current density, and competitive hydrogen production. Recently, technologies such as gas diffusion electrodes, enrichment of reactant on catalysts surface and tandem catalytic sites have been applied to solve these problems and surprising progress has been made. In order to reduce the driving voltage of the actual two electrode electrolytic cell, some small molecules (hydrogen sulfide and glycerol) are used as backup oxidation reaction to replace slow kinetic oxygen evolution reaction, with nitrogenous pollutants reduction reactions as cathode reaction. In addition, efficient nitrogenous pollutants catalysts are also used to construct clean batteries for simultaneous nitrogenous pollutant recovery, ammonia synthesis, and electrical energy output. It is worth noting that nitrogenous pollutant reaction can also be combined with carbon dioxide reduction reaction to achieve the synthesis of carbon nitrogen compounds, which further expands the application scope of nitrogenous pollutant reaction. The research progress in the field of nitrogenous pollutants reduction is highlighted in this review. Finally, challenges facing and possible development direction in the future are presented. This review will hopefully provide suggestions for the industrial application of the electrochemical reduction of nitrogenous pollutants. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • The uniform hierarchical microspheres MoNi synthesized from reducing NiMoO 4. • The MoNi HM exhibited a superior HER activity with a onset potential of −7 mV. • The MoNi HM was used as cocatalyst for photocatalytic HER with rate of 151.7 μmol mg−1 h−1. • This study revealed a process for building highly efficient electrocatalyst and cocatalyst. Abstract In industrial water electrolysis cell, the electrocatalyst has a sluggish water dissociation kinetics leading to low electrocatalytic activity for the generation of H 2 from water splitting. This work reports a hierarchical microsphere constructed by MoNi porous nanosheets derived from NiMoO 4 microsphere, as a rapid Tafel-step-decided electrocatalyst towards hydrogen evolution reaction (HER). Consequently, the synthesized MoNi hierarchical microsphere (MoNi HM) electrocatalyst exhibits an onset potential of as small as −7 mV vs. RHE, an operating potential of 72 mV for 10 mA cm−2, and a low Tafel slope of 36.6 mV per decade in 1.0 M KOH. Furthermore, MoNi HM as cocatalyst and CdS nanowires as photocatalyst are physically mixed (MoNi HM/CdS NWs) and presentes a champion photocatalytic performance for H 2 production with a prominent H 2 generation rate of as high as 151.7 μmol mg-1 h−1 at λ > 420 nm light illumination. The large contact area between MoNi nanosheets and CdS nanowires endows the fast separation of photogenerated charge carriers to significantly facilitate the photocatalytic H 2 production. [ABSTRACT FROM AUTHOR]

Highlights • N doped carbon-wrapped Mo x C heterophase sheets are synthesized via in situ carbonation. • N-Mo x C@C HSs effectively combine the respective advantages of both γ-MoC and β-Mo 2 C. • Heterostructures possess a synergistically-enhanced activity on the interface and surface of γ-MoC/β-Mo 2 C. • N-Mo x C@C HSs exhibit excellent activity and stability in acid media. Abstract Advancement of non-precious-metal catalysts for hydrogen evolution reactions (HER) with both prominent activity and excellent stability has been becoming an ongoing challenge in the following decades. Herein, N-doped carbon-wrapped molybdenum carbide heterophase (γ-MoC and β-Mo 2 C) sheets (N-Mo x C@C HSs) were prepared by a facile chemical vapor reduction (CVR) procedure and following calcination at desired temperatures. The best HER electrocatalytic activity of N-Mo x C@C HSs was detailedly examined in 0.5 M H 2 SO 4 , which exhibited a small overpotential of 172 mV (10 mA cm−2) with a Tafel slope of only 60 mV dec−1 and durability. The improved HER activities and catalytic stability were due to heterocrystal Mo x C, nitrogen doping, and carbon coating. Particularly, this study effectively combined the respective advantages of both γ-MoC and β-Mo 2 C via the interface effect and matched polarity of hydrogen adsorption. [ABSTRACT FROM AUTHOR]

Abstract Since the content of alkaloids is usually low in plants and they are easily co-eluted with other constituents, enrichment of alkaloids is essential in the discovery of bioactive lead compounds from natural products. In this paper, an easy SPE enrichment method was developed in a buffer-free solvent system based on electrostatic repulsion mechanism. The feasibility of the new method was verified by successful enrichment of alkaloids from Scopolia tangutica (S. tangutica) with an optimized eluting condition. Then this developed method was applied to other representative plants in different families, including Przewalskia tangutica and Peganum harmala L , Lycoris radiata and Menispermum dauricum DC , which enlarged the scope of applicability. Additionally, the new SPE procedure avoided possible structural change destruction caused by pH change. Simple solvent system, including formic acid (FA) and methanol, would benefit subsequent mass analysis, quantity determination and bioactivity screening, and so on. Highlights • We successfully developed a buffer-free alkaloids enrichment method using AC18 as a RP/SAX material. • AC18 with high charge density could elute alkaloid constituent efficiently and selectively. • This method could enrich alkaloids easily and benefit subsequent procedure such as activity screening and LC–MS analysis. • Mild acidic solvent system helped avoid possible structural damage caused by pH change for pH-sensitive alkaloids. • This method was applied successful in alkaloids enrichment from S. tangutica and four other TCMs. [ABSTRACT FROM AUTHOR]

To achieve sustainable production of H 2 fuel through water splitting, noble-metal-free catalysts have been extensively studied for hydrogen evolution reaction (HER), especially molybdenum-based catalysts. Herein, we report the Ni, N-codoped MoC x (Ni–N–MoC x ) nanoparticles synthesized from NiMoO 4 precursor by oily-solvent-assisted strategy, following the calcination with dicyandiamide. As-obtained Ni–N–MoC x in different magnified SEM images shows grainy structure, MoC x nanoparticles uniformly disperse in carbon substrate. The obtained electrocatalysts can also efficiently electrocatalytic HER in a wide pH value. Ni–N–MoC x shows an onset potential of −74 mV, an overpotential of 163 mV to reach a current density of 10 mA/cm 2 in acid media, an onset potential of −37 mV and overpotential of 124 mV to reach 10 mA/cm 2 in alkaline media. The present study provides some guidelines for preparing the uniformly doped electrocatalysts from multiple compounds with devolatilization characteristics. [ABSTRACT FROM AUTHOR]

The global warming makes us focus on the resource utilization of CO 2. Herein, defective TiO x nanoparticles with rich oxygen vacancies are synthesized through laser bombardment, and uniform Ru nanoparticles are loaded on the TiO x (Ru-TiO x) by the assistance of photothermal reduction. Assisted by the high photothermal conversion efficiency of defective TiO x (259.3 °C), the photothermal co-catalytic methane yield of Ru-TiO x reaches 15.84 mmol/g/h with high selectivity (99.99%). After comparing the methane yields in different wavelengths, the synergistic effect between photocatalysis and thermocatalysis of Ru-TiO x is confirmed. The theoretical calculation demonstrates that the deoxidation active sites of TiO x and hydrogenation active sites of Ru are responsible for high activity and selectivity. Furthermore, the excellent photothermal co-catalytic activity (about 1 mmol/g/h for cloudless days) and stability under outdoor sunlight are demonstrated. This work confirms that the Ru-TiO x system synthesized via laser bombardment has practical application value in photothermal co-catalysis of CO 2 hydrogenation. [Display omitted] • TiO x nanoparticles with high photothermal conversion capacity are prepared by laser bombardment. • The deoxidation sites of TiO x and hydrogenation sites of Ru are responsible for high activity and selectivity. • The synergy between photocatalysis and thermocatalysis is confirmed. • An excellent catalytic activity and stability under the outdoor sunlight verify the practical applicability. [ABSTRACT FROM AUTHOR]

Cobalt nanoparticles encapsulated in nitrogen-doped carbon nanotubes (Co@N C) are obtained by a simple pyrolysis of Co-MOF (ZIF-67) for the bifunctional water recovery and hydrogen production. The results showed that calcination temperature of ZIF-67 significantly affected the morphology and catalytic performance. Wastewater are effectively recovered in the presence of the Co@N C and oxidant, which is promoted by anodic oxidation reactions. Co@N C as the cathode catalyst exhibited excellent hydrogen evolution reaction catalytic activity with a low onset potential of −51 mV (vs. RHE, current density of 0.5 mA/cm 2 ), Tafel slope of 96.73 mV/dec and extraordinary long-term durability. Finally, as a proof of concept, a home-made two-electrode device employed Co@N C as both anode and cathode catalyst for continuous water recovery and simultaneous hydrogen production, which possesses the possibly applications in solving the environmental pollution and energy crisis. [ABSTRACT FROM AUTHOR]

The development of photoelectrodes capable of light-driven hydrogen evolution from water with non-noble metals is an important approach for the storage of solar energy in the form of a chemical energy carrier. In this study, we report Co nanoparticles@N-doped carbon coated on carbon nanotube@defective-silica (CNTs@Co@NC/D-SiO 2 ), which are composed of Co nanoparticles@N-doped carbon as electrocatalyst, defective-silica as photocatalyst and carbon nanotube as conductive substrates. The obtained non-noble photocathode possesses the high performance for efficient photoelectrochemical hydrogen evolution reaction. When evaluated for hydrogen evolution reaction electrocatalysis, CNTs@Co@NC/D-SiO 2 exhibits a small onset overpotential of 104 mV (J = 1 mA cm −2 ), a Tafel slope of 69.1 mV dec −1 and outstanding long-term cycling stability. The P type semiconductor characteristics of CNTs@Co@NC/D-SiO 2 due to defective-silica with carrier concentration of 3.53 × 10 19 cm −3 is measured, which produces a significant positive shift of overpotential of 40 mV (J = 10 mA cm −2 ) under 100 mW cm −2 simulated sunlight irradiation. These findings provide a straightforward and effective route to produce cheap and efficient photo-electro-catalyst for water splitting. [ABSTRACT FROM AUTHOR]

Here we reported the preparation of Ti 3 C 2 MXene and Ti 2 C MXene by etching Ti 3 AlC 2 and Ti 2 AlC with various fluoride salts in hydrochloric acid (HCl), including lithium fluoride (LiF), sodium fluoride (NaF), potassium fluoride (KF), and ammonium fluoride (NH 4 F). As-prepared Ti 2 C was further delaminated by urea, dimethylsulfoxide or ammonium hydroxide. Based on theoretical calculation and XPS results, the type of positive ions (Li + , Na + , K + , or NH 4 + ) in etchant solution affect the surface structure of prepared MXene, which, in turn, affects the methane adsorption properties of MXene. The highest methane adsorption capacity is 8.5 cm 3 /g for Ti 3 C 2 and 11.6 cm 3 /g for Ti 2 C. MXenes made from LiF and NH 4 F can absorb methane under high pressure and can keep methane under normal pressure, these MXenes may have important application on capturing methane or other hazardous gas molecules. MXenes made from NaF and KF can absorb methane under high pressure and release methane under low pressure. They can have important application in the adsorb storage of nature gas. [ABSTRACT FROM AUTHOR]

Co-catalysts for H 2 production are often made from expensive noble metals, such as the most efficient Pt. The alternative non-noble metal co-catalysts with low cost and high efficiency are therefore highly desirable for economically viable H 2 production. Herein, we demonstrated that a CdS/MoS 2 /Mo sheets system simultaneously containing photocatalysts, co-catalysts, and conductive supports, was prepared via the one-step hydrothermal process by Mo sheets as template and Mo sources. The obtained CdS/MoS 2 /Mo sheets possess the superior photocatalytic H 2 production via water splitting under visible light irradiation, which achieved an extraordinary H 2 production of 4540 μmol h −1 g −1 , up to 28.6 and 3.6 times greater than that of CdS alone and Pt/CdS. The synergetic effect of MoS 2 as co-catalysts and Mo sheets as conductive supports contribute to the dramatically improved photocatalytic H 2 evolution activity of CdS photocatalysts, by means of facilitating charge carriers separation and providing active sites for proton reduction. These findings provide a straightforward and practical route to produce cheap and efficient co-catalysts for large-scale water splitting. [ABSTRACT FROM AUTHOR]

[Display omitted] • 1. Spin-polarized Ni-Fe-Mo alloys were prepared by a magnetic field-assisted method. • 2. Ni-Fe-Mo alloys with enduring spin polarization can realize higher OER activity. • 3. Providing a promising strategy to prepare efficient ferromagnetic alloy catalysts. The oxygen evolution reaction (OER) constrains the efficiency of water splitting. The catalytic activity of electrocatalysts is mostly determined by the electronic structure, which is expressed as the electron transfer property and the reactant adsorption–desorption capacity. Ferromagnetic electrocatalysts exhibit promising applications in OER. However, an external magnetic field is indispensable for the electron spin polarization of ferromagnetic materials. Here, Ni-Fe-Mo ternary alloy nanowire electrocatalysts were prepared via a magnetic field-assisted self-assembly method in an aqueous-solution system at a mild temperature (65 °C). These Ni-Fe-Mo ternary alloy electrodes feature a spin polarization-dependent OER catalytic performance, which is attributed to ferromagnetic regulation. Ni 0.8 Fe 0.15 Mo 0.05 possesses the maximum ferromagnetism compared to other electrodes (Ni 0.8 Mo 0.2 and Ni 0.8 Fe 0.2) and improved substantially OER activity. The regulated OER activity is assigned to the favorable adsorption of oxygen-containing intermediates (OH*) due to Ni-Fe-Mo composition-dependent, and the accelerated kinetics of OER with enduring spin polarization. The Ni-Fe-Mo ternary alloy nanowires with higher magnetic properties contribute to in situ spin polarization at the surface. This magnetic field-assisted synthesis approach provides a new strategy to realize electrodes with enduring spin polarized. [ABSTRACT FROM AUTHOR]

Highly active and earth-abundant catalysts for hydrogen evolution reaction (HER) play a crucial in the development of efficient water splitting to produce hydrogen fuel. Here, we reported a simple, facile and effective strategy to fabricate N-doped molybdenum sulfide (N-doped MoS 2 ) as noble metal-free catalysts for HER. Compared with pure MoS 2 , the obtained N-doped MoS 2 catalyst revealed enhanced HER performance with low overpotential of −168 mV (−10 mA cm −2 ), small Tafel slope of 40.5 mV dec −1 and excellent stability. The superior HER activity may originate from both the exposed Mo active sites due to S defects and the optimized electron density state of S atoms by N doping. More importantly, due to its simple synthesis method, earth-abundant catalysts and high catalytic activity, the N-doped MoS 2 will become a promising HER catalysts for water splitting. [ABSTRACT FROM AUTHOR]

• The prepared MoO 2 -NSs exhibit excellent nonlinear absorption properties. • The passive Q-switching operation is first achieved by MoO 2 -NSs SA in the laser field. • Mode-locked laser based on the MoO 2 -NSs SA is also realized for the first time. • The MoO 2 -NSs exhibit promising applications as an optical modulation device. Molybdenum dioxide nanosheets (MoO 2 -NSs), as two-dimensional (2D) materials, have attracted broad attention owing to their high damage threshold, good stability, strong localized surface plasmon resonance (LSPR), affordability, and excellent physicochemical properties. In this work, we successfully synthesized high-quality MoO 2 -NSs through chemical vapor deposition synthesis method and characterized the morphology and structure of the prepared materials in detail. The saturable absorption characteristics of the MoO 2 -NSs were measured using Z-scan experiments for the first time. Additionally, the compact Q-switched laser and stable mode-locked laser were successfully realized based on a MoO 2 -NSs saturable absorber (SA). To the best of our knowledge, this is the first presentation of the application of MoO 2 -NSs SA in the field of ultrafast photonics. These findings indicate that high-quality MoO 2 -NSs can be an effective optical modulator for generating high-repetition-rate pulsed lasers, and exhibit promising potential applications in mode-locked ultrafast lasers. [ABSTRACT FROM AUTHOR]

Conventional electrocatalysts underperform with reaction kinetics, nitrogen dissociation, and activated hydrogen recombination, demanding effective strategies for improving electrochemical nitrogen fixation. The challenge lies in the rational design of electron back-donating centers for nitrogen activation and hydrogen migration path optimization. This study proposes an effective laser-tuning strategy to construct noble-metal Lewis acid sites on molybdenum carbide (M-Mo 2 C, M = Ru, Rh, Pd, Ir), yielding a more active material system by mimicking π back-donation behavior. Laser-tuned Lewis acid sites can effectively break N≡N bonds, lower thermodynamic energy barrier of the rate-determining hydrogenation step (*NN → *N-NH), and optimize hydrogen migration pathway. The Rh-Mo 2 C shows superior NRR activity with NH 3 yield of ∼26.3 µg h−1 cm−2 cat. and Faradaic efficiency of ∼15.4%, which are 5.1- and 3.6-fold higher than those of Mo 2 C, respectively. This work demonstrates a unique and universal strategy for designing high-performance electrocatalysts by accurately manipulating electronic structure of active sites. [Display omitted] • A series of noble-metal-Mo 2 C with optimized interfacial microstructure was constructed by laser tuning strategy. • Low energy barrier of the rate-determining hydrogenation step (*NN → *N-NH) was achieved on Rh-Mo 2 C. • In situ characterizations and isotope labelling experiments confirmed the effectiveness of nitrogen fixation. • Noble metal Lewis acid sites effectively optimized hydrogen migration pathway to promote nitrogen fixation selectivity. [ABSTRACT FROM AUTHOR]

Peptide A3-capped gold and silver nanoparticles were prepared by chemical reduction of metal salt precursors. The nanoparticles exhibited apparent but distinctly different color changes upon the addition of selected heavy metal ions. For gold nanoparticles, the solution color was found to change from red to blue in the presence of Hg 2+ or As 3+ ions, accompanied with broadening and a red-shift of the surface plasmon resonance peak. In contrast, silver nanoparticles showed an apparent color change from yellow to colorless only in the presence of Hg 2+ , along with a blue-shift and diminishment of the surface plasmon resonance peak. The Hg 2+ reaction concentration limit of silver nanoparticle was about 40 times lower than that of gold nanoparticle. Based on the dynamic light scattering, transmission electron microscopy and X-ray photoelectron spectroscopic results, the reaction mechanism has been proposed. Such a sensitive variation of the nanoparticle optical properties to selective ions might be exploited for ion detection for potential applications. [ABSTRACT FROM AUTHOR]

An ultrasensitive capacitive tactile sensor was fabricated for tiny signal perception. The hierarchical sea-urchin TiO 2 particle-in-micropore structure in the dielectric layer induces stress concentration near the micropore regions, significantly enhancing the sensitivity and toughness of the device. The sparsely spaced large microcone improves the sensitivity of the hierarchical microcone structure in the electrode layer, while the small microcone reduces the hysteresis caused by interfacial adhesion. [Display omitted] • Simultaneous introduction of heterostructures in electrode and sensing layers. • HSP-MP structure is fabricated by mixed solvent phase separation method. • HM structure is fabricated by laser marking Cu template transfer method. • An ultrasensitive capacitive tactile sensor for tiny signal perception. The development of capacitive tactile sensors with both ultrasensitivity and ultrafast response/relaxation is crucial for the development of intelligent healthcare monitoring technology. Despite the significant improvement in the sensing performance presented by the introduction of microstructures into the dielectric or electrode layers, meeting the demands of intellectualization remains a major challenge. Herein, a strategy to simultaneously introduce microstructures in both the dielectric and electrode layers is developed. The hierarchical sea-urchin TiO 2 particle-in-micropore (HSP-MP) structure in the dielectric layer induces stress concentration near the micropore regions, significantly enhancing the sensitivity and toughness of the device. The sparsely spaced large microcone improves the sensitivity of the hierarchical microcone (HM) structure in the electrode layer, while the small microcone reduces the hysteresis caused by interfacial adhesion. With the synergistic effect of the HSP-MP&HM structure, the proposed tactile sensor achieves ultrasensitivity of 10.5 kPa−1, ultrafast response/relaxation time of 5.6/5.6 ms, and ultralow limit of detection of 0.1 Pa. These sensing properties are demonstrated in practical applications, including tiny signal perception of the human fingertip pulse, tiny muscle motion perception for Morse code transmission, and high-resolution flexible perception array with pressure mapping capability. [ABSTRACT FROM AUTHOR]

This communication describes metallic MoO 2−x nanobelts intrinsic photocatalytic CO 2 reduction performance in pure water. The intrinsic wide-bandgap endowed MoO 2 nanobelts great potential for CO 2 reduction in ultraviolet, while localized surface plasmonic resonance (LSPR) and the metallic feature induced by oxygen vacancies ensured energetic electrons transform and fast kinetic transfer. Credit to the unique degenerate doping properties of MoO 2−x nanobelts, the absorbed wavelength of intrinsic semiconductor bandgap overlapped with the LSPR absorption. Therefore, the high performance was ascribed to the self-coupling of intrinsic excited photoelectrons and plasmonic hot electrons. The surface abundant oxygen vacancies also facilitated preferable adsorption of CO 2 and hence promoted the chemical activation. The according intrinsic CO production rate was 62.75 µmol/g/h in pure water under ultraviolet light, which was 6 times higher than that of commercial P25 photocatalyst (11.13 µmol/g/h). Our findings provide new insights and inspirations for parsing the mechanism and developing new-type MoO 2 -based photocatalysts. [Display omitted] • The LSPR and metallicity of MoO 2-x could be regulated by controllable regulated by adjusting the concentration of oxygen vacancies. • The absorbed wavelength of the intrinsic semiconductor bandgap overlapped with the LSPR absorption. • The intrinsic excited photoelectrons were self-coupled with the plasmonic hot electrons, which significantly enhanced the photocatalytic CO 2 performance. • The instinct photocatalytic performance of MoO 2-x nanobelts (62.75 µmol/g/h) was accurately quantified in pure water. [ABSTRACT FROM AUTHOR]

The efficient electrocatalysts for hydrogen evolution reaction (HER) are indispensable. Herein, Mo 2 C micropillars decorated with Pt nanoparticles (<4 nm) on Mo foil (Pt/Mo 2 C-L/Mo) are synthesized by laser ablation in a focused mode in CH 4 atmosphere and laser-induced reduction in an under-focused mode in Ar/H 2 atmosphere. The Pt/Mo 2 C-L/Mo possesses excellent HER performance (21 mV at 10 mA cm−2) and stability (1317 mA cm−2 for 100 h) in acid media. Integrated gas diffusion and catalytic electrodes of Pt/Mo 2 C-L/Mo are constructed by laser in a mixed model and used in proton exchange membrane water electrolyzer (PEMWE). The voltage of the constructed PEMWE of (−) Pt/Mo 2 C-L/Mo || IrO 2 /Ti (+) (1.55 V at 10 mA cm−2) is lower than that of (−) 20 wt.% Pt/C || IrO 2 (+) (1.69 V at 10 mA cm−2) for overall water splitting. This work provides a universal laser synthetic strategy of integrated electrodes with promising application in the field of hydrogen energy. [Display omitted] • The Pt anchored Mo 2 C micropillars (Pt/Mo 2 C-L/Mo) were rapidly fabricated by laser at normal temperature. • The Pt/Mo 2 C-L/Mo possessed high active HER performance and large current density stability in acid media. • The integrated Pt/Mo 2 C-L/Mo electrode simplified the structure of proton exchange membrane water electrolyzer (PEMWE). • The simplified PEMWE of (−) Pt/Mo 2 C-L/Mo||IrO 2 /Ti (+) performed an excellent water splitting performance. [ABSTRACT FROM AUTHOR]

Antimony chalcogenides emerge as a type of efficient material for solar cells. In particular, antimony sulfide-selenide (SbSSe) has attracted significant interests based on their simple preparation, excellent photoelectric performance, and tunable bandgaps. In this study, by applying energy-band engineering technologies, we achieved carrier transport balance and light absorption balance for SbSSe single- and triple-junction solar cells, respectively. First in a single junction solar cell, the photoelectric conversion efficiency (PCE) of SbSSe solar cells is improved from 13.14% to 16.16% with a front-gradient Se content structure compared to a non-gradient Se content SbSSe solar cell. This improvement is attributed to the additional electric field induced by such a gradient bandgap, promoting the carrier motion. Consequently, the balance of carrier transport is realized by adjusting the drift velocities of holes and electrons simultaneously, thereby surpassing carrier recombination and improving the device parameters of short-circuit current density (J sc) and fill factor (FF). In a next step, an SbSSe of advanced gradient bandgap has been applied as the absorber layer of middle-cell in an antimony chalcogenide based triple-junction solar cell. Based on the high J sc and FF advantages of SbSSe sub-cells with front-gradient Se content structure, the uniform absorption of sunlight in each sub-cell and current matching of tandem solar cells could be easily realized. Eventually, the PCE of the triple-junction solar cell exhibits an enhancement from 17.34% to 19.51%. Our results demonstrate that the application of energy-band engineering technology can effectively improve device performance, providing theoretical guidance for the refined design and nanomanufacturing development of antimony chalcogenide solar cells. • Balanced carrier transport can be realized in a front-gradient SbSSe absorber. • Front-gradient SbSSe can form an additional electric field to promote hole transport. • A front-gradient SbSSe solar cell yields a high FF and J sc. • Applying a front-gradient SbSSe middle cell can enhance the triple-junction solar cell performance. [ABSTRACT FROM AUTHOR]

To achieve the efficient electrocatalytic upgrading of nitrate (NO 3 −) and hydrogen sulfide (H 2 S) to value-added ammonia (NH 3) and sulfur (S) from wastewater, herein, we report a remarkable nitrogen-doped carbon nanotubes encapsulated iron carbide array electrode (Fe 3 C@N-CNTs/IF) as both cathode and anode for the efficient electrocatalytic reduction of NO 3 − to NH 3 and oxidation of H 2 S to S, respectively. Both experimental and theoretical calculation confirm the high activity of Fe 3 C@N-CNTs/IF. A maximal NH 3 faradaic efficiency of ~97.9% with the yield rate of 0.922 mg h−1 cm−2 at − 1.1 V vs. SCE and the S yield rate of 33.76 mg h−1 cm−2 at the current density of 100 mA cm−2 can be achieved. In addition, a flow cell is employed with a multifunctional Fe 3 C@N-CNTs/IF electrode with channels made by laser to maintains excellent stability for continuous upcycling NO 3 − and H 2 S to produce NH 3 and S, which demonstrates its massive potential for practical application. [Display omitted] • Fe 3 C@N-CNTs/IF is a bi-functional electrode for NO 3 − reduction and H 2 S oxidation. • High FE (97.9%) and yield (0.922 mg h−1 cm−2) of NH 3 was achieved at − 1.1 V. • S yield rate of 33.76 mg h−1 cm−2 is achieved at the current density of 100 mA cm−2. • A flow cell is employed for continuous upcycling NO 3 − and H 2 S to produce NH 3 and S. [ABSTRACT FROM AUTHOR]

Formate synthesis by CO 2 electroreduction reaction (CO 2 RR) has been considered as a promising strategy for mitigating the excessive CO 2. Here, we synthesize Cu 6 Sn 5 alloy on Sn foil (Cu 6 Sn 5 /Sn) and gas diffusion electrode (GDE) using laser irradiation. Cu 6 Sn 5 /Sn exhibits high formate faradaic efficiency (FE formate) of 87.2% and remains stable at 28.69 mA cm−2 over 14 h. Further, with the help of laser drilling, the channeled Cu 6 Sn 5 /Sn used directly as GDE shows increased current density (118 mA cm−2) and steady FE formate (86.69%) in flow cell. Density functional theory (DFT) calculations reveal that the high performance of Cu 6 Sn 5 /Sn benefits from the appropriate binding energy of the key intermediates *OCHO. Meanwhile, COMSOL simulation results of CO 2 concentration and electric field distribution combined with the results of kelvin probe force microscopy (KPFM) prove that CO 2 RR prefers to occur around the channels of electrode. More importantly, this laser irradiation method is also available to synthesize other alloy electrocatalysts. [Display omitted] • Cu 6 Sn 5 alloy were synthesized through laser irradiation. • The channeled Cu 6 Sn 5 /Sn prepared by laser drilling could directly use as GDE, and the current density increased 4-fold. • The enhanced CO 2 electroreduction performance was revealed by COMSOL Multiphysics simulation and KPFM. [ABSTRACT FROM AUTHOR]

• S-Ta 2 O 5 /CdS is synthesized through the interfacial diffusion reaction. • S-doped Ta 2 O 5 as co-catalyst was studied in the photocatalytic reaction. • The structure could effectively improve the photo-corrosion of CdS. Photocatalytic H 2 generation is considered to be one of the most promising technologies for H 2 production. Herein, S doped Ta 2 O 5 decorated CdS nanosphere (S-Ta 2 O 5 /CdS) is synthesized through the interfacial diffusion reaction between sublimation of cadmium sulfide and crystallization shrinkage of tantalum oxide, which was regulated by high-temperature calcination. The successful S doping causes the changes of energy band structure of Ta 2 O 5 , which can be used as co-catalyst with suitable hydrogen potential to enhance the photocatalytic activity of CdS nanosphere. The obtained S-Ta 2 O 5 /CdS possesses the photocatalytic hydrogen generation rate of 54.51 μmol·mg−1·h−1 with improved photocatalytic stability under visible light irradiation, which is better than those of CdS (1.51 μmol·mg−1·h−1) and Ta 2 O 5 (0 μmol·mg−1·h−1). The work offers a new perspective that S-Ta 2 O 5 as co-catalyst improves the separation efficiency of photogenerated electron-hole for the visible-light photocatalytic hydrogen production. [ABSTRACT FROM AUTHOR]

A facile method was demonstrated for the preparation of Pt 3 Ni alloy nanoparticles supported on a sandwich-like graphene sheets/carbon nanospheres/graphene sheets substrate (Pt 3 Ni–C/rGO) through a one-pot solvothermal process in N,N-dimethylformide without the addition of reducing agents and surfactants. Transmission electron microscopic measurements showed that carbon nanospheres were homogeneously dispersed in the matrix of exfoliated graphene sheets, and Pt 3 Ni nanoparticles were distributed on the graphene surfaces without apparent agglomeration, where the average core size was estimated to be 12.6 ± 2.4 nm. X-ray photoelectron spectroscopic studies demonstrated that electron transfer likely occurred from the Pt 3 Ni alloy nanoparticles to the graphene sheets. Electrochemical measurements showed that the mass activity of the Pt 3 Ni–C/rGO catalysts in methanol oxidation was 1.7-times higher than that of Pt 3 Ni nanoparticles supported on reduced graphene oxide alone (Pt 3 Ni/rGO), and 1.3-times higher than that of commercial Pt/C (20 wt%). Additionally, CO tolerance and durability were also remarkably enhanced. These superior electrocatalytic activities were attributed to the following major factors: (i) the insertion of carbon nanospheres into the graphene matrix prevented restacking/refolding of the graphene sheets, leading to an increasing number of accessible active sites as well as transport channels for mass and charges; and (ii) the synergetic effect between Pt 3 Ni nanoparticles and rGO weakened the bonding interactions with reactant species, as manifested by the enhanced kinetics of methanol oxidation and CO oxidative desorption. [ABSTRACT FROM AUTHOR]

[Display omitted] • Co-MOF is used to uptake SeO 3 2−, and the capacity reaches to 280.0 mg g−1. • R-CoSeO 4 is recycled as an OER electrocatalyst in wastewater treatment process. • Co-Co 0.85 Se, an efficient HER electrocatalyst, is obtained by calcining of R-CoSeO 4. • R-CoSeO 4 /CC and Co-Co 0.85 Se/CC are constructed a cell for water electrolysis. A nanosheet-like cobalt-based metal-organic-framework (Co-MOF) is employed to uptake SeO 3 2− anions, and the remove capacity of Co-MOF reaches a record of 280.0 mg g−1. After uptake SeO 3 2− by Co-MOF, the recycling defect-rich CoSeO 4 (R-CoSeO 4) is used as an electrocatalyst for oxygen evolution reaction (OER), which displays an overpotential of 265 mV at 10 mA cm−2 in 1 M KOH. Furthermore, cobalt-cobalt selenide heterojunction nanoparticle (Co-Co 0.85 Se), a high-performance hydrogen evolution reaction (HER) electrocatalyst (overpotential of 97 mV at 10 mA cm−2 in 1 M KOH) is obtained by one-step calcining of R-CoSeO 4. Series experiments and density functional theory calculations confirm the anion vacancy in R-CoSeO 4 and heterojunction in Co-Co 0.85 Se can improve the OER and HER activity, respectively. Finally, two binder-free electrodes (R-CoSeO 4 /CC and Co-Co 0.85 Se/CC) are employed as anode and cathode, respectively, to construct a water electrolysis cell, which only needs 1.47 V to achieve 10 mA cm−2 in 1 M KOH. [ABSTRACT FROM AUTHOR]

[Display omitted] • The crystalline V-doped CoO nanosheets were obtained by cathode electrochemical reconstruction of amorphous VCoO. • The crystallineV-doped CoO exhibited better HER active than amorphous VCoO. • Nanosheets structure could provide abundant active sites. • Vanadium doping effectively increased the intrinsic activity of CoO (1 1 1) and the number of active sites. • The V-doped CoO nanosheets display superb performance for HER at high potential. In the search for nonprecious metal catalysts to achieving active industrial hydrogen evolution reaction (HER), transition metal oxides (TMOs) have been proposed as promising candidates. In various synthetic methods for preparation of TMO electrocatalysts, electrochemical reconstruction, as one of the most efficient and controlled way, attracts much attentions. However, most of reported electrochemical reconstruction is usually carried out on the surface of anode via electrochemical oxidation reaction, and the investigations of cathode electrochemical reconstruction are rarely reported. Here, V-doped CoO nanosheets (V-CoO) are successfully prepared via cathode electrochemical reconstruction of amorphous VCoO. The reconstruction process and principle are studied in detail. Compared with the previous oxides, the obtained V-CoO possesses the promoted HER performance with overpotential of 280 mV at − 100 mA cm−2 and superior durability at − 1.07 V vs. RHE for 20 h. DFT calculations further reveals that vanadium doping effectively improves the intrinsic activity of oxides and HER active sites located at Co side of V-CoO (1 1 1) facet is the favorable H* adsorption site of reconstructed oxides. This work highlights the importance of electrochemical reconstruction on cathode to improve the HER activity of TMOs. [ABSTRACT FROM AUTHOR]

Periodically poled lithium niobate is an important component in mid-infrared lasers due to its perfect nonlinear optical property. However, fabrication of high-power laser based on periodically poled lithium niobate is still a great challenge, because lithium niobate crystal wafer with large thickness for large clear aperture periodically poled lithium niobate is hard to be completely poled due to the high coercive field of commercial congruent lithium niobate (LiNbO 3). In this work, we have successfully grown 3-inch near-stoichiometric LiNbO 3 by efficiently regulation of temperature gradient with the aid of thermal field simulation. Characteristics on the as-grown large size near-stoichiometric LiNbO 3 proved that the [Li]/[Nb] of crystal is around 1:1, and the crystal possesses a typical single domain with high optical homogeneity. Compared with congruent and Mg-doped LiNbO 3 , the near-stoichiometric LiNbO 3 crystal has better piezoelectric performance. The forward and backward coercive fields of the near-stoichiometric LiNbO 3 crystal were 2.90 kV/mm and 2.43 kV/mm, respectively, which were approximately 8 times lower than that for CLN (21 kV/mm). The periodically polarization experiments proved that only 1.36 kV can realize the complete polarization for a 1 mm thick near-stoichiometric LiNbO 3 wafer. The mass-productive near-stoichiometric LiNbO 3 crystals grown in this work will have great applications in high-power mid-infrared solid-state laser. • We have successfully grown 3-inch near-stoichiometric LiNbO 3 single crystal. • Discussion of temperature gradient with the aid of thermal field simulation. • A 1 mm thick periodically poled near-stoichiometric LiNbO 3 was fabricated. [ABSTRACT FROM AUTHOR]

• Phytic acid was used to controllably prepare heterostructural electrocatalyst. • HCHO-based water electrolysis saves 320 mV to reach 50 mA cm−2 than without HCHO. • The conversion of HCHO to CH 3 OH was realized with hydrogen sources from water. • This electrocatalytic system could be applied to detect HCHO widely in wastewater. Herein, we report the linearly distributed NiCo-NiCoP nanoparticles embedded into P-doped carbon nanotubes (NiCo-NiCoP@PCT) which are synthesized via the chelation of phytic acid (PA) on the surface of Ni-Co-precursor nanowires and the subsequent thermal reduction. The PA is used not only as chelating agent to form Ni-Co@PA coating but also as solid phosphorus source to safely synthesize heterostructured NiCo-NiCoP. The as-prepared NiCo-NiCoP@PCT used as bifunctional electrodes exhibit superiorly electrocatalytic performance toward both hydrogen evolution reaction (HER) with a low overpotential of 135 mV at 10 mA cm−2 and anodic oxidation reaction of formaldehyde (FOR) with an ultra-low overpotential of 1.18 V to acquire 10 mA cm−2. Besides, when a two-electrode cell is constructed by using NiCo-NiCoP@PCT as anode and cathode, the current density of formaldehyde-based water electrolysis (50 mA cm−2) is 6.25 times bigger than that of conventional water splitting (8 mA cm−2) at the same voltage of 1.76 V. In addition, methanol (CH 3 OH) is produced simultaneously by hydrogenation reduction reaction of formaldehyde at the cathode, which realized the upgraded conversion of HCHO to small molecular fuel by electrocatalytic reduction. Therefore, it is demonstrated that the two-electrode electrolyzer not only realize the oxidative degradation and upgraded conversion of formaldehyde-based wastewater, but also reduce the energy consumption of water splitting for hydrogen generation. This work presents a new idea of controllable preparation for multifunctional phosphide electrodes and a novel construction of electrochemical cell to realize efficient hydrogen energy preparation and environmental management. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hierarchical CoNi 2 S 4 /WS 2 /Co 9 S 8 (NiCoWS) frameworks were constructed. • NiCoWS featured with highly exposed active multi-heterointerfaces. • NiCoWS exhibited robust electrocatalytic performance toward all-pH HER. • The synergy among geometric, electronic, and interfacial structures was achieved. Water dissociation, hydroxyl desorption, and hydrogen recombination are three major prerequisites for all-pH hydrogen evolution reaction (HER). Herein, a multi-interfacial engineering in hierarchical CoNi 2 S 4 /WS 2 /Co 9 S 8 (NiCoWS) hybrid frameworks was developed. The NiCoWS is composed of highly exposed active sites and abundant heterogeneous interfaces. The NiCoWS exhibits small overpotentials of 70 mV, 61 mV, and 146 mV at 10 mA cm−2 in alkaline, acid, and neutral medium, respectively, for HER. The robust performance of NiCoWS should originate from the collective synergy of special morphological, electronic, and interfacial structures. The hierarchical nanosheet framework can facilitate the transport of charge/mass as well as the exposure of more active interface sites. Density functional theory (DFT) calculations verify that the multi-interfacial engineering in NiCoWS can endow the electrocatalyst with enhanced electrical conductivity and favorable adsorption energies of H*, H 2 O* and H...OH*. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hybrid nanostructure of RuO 2 and NiMoO was fabricated via highly matched lattices. • Integrated NiMoO works like a turbo through optimizing the intermediates adsorption. • RuO 2 -NiMoO exhibits enhanced electrocatalytic activity for overall water splitting. • The synergy among geometric, electronic, and interfacial structures is crucial. Cooperative promotions of intrinsic activity, active sites amount, and mass transfer/charge transport in electrocatalytic process are highly depending on the fundamental understanding of reaction mechanism and the systematic and elaborate designing of morphological, electronic, and interfacial structure of electrocatalyst. Herein, a hybrid nanostructure of RuO 2 strongly coupled with structurally controllable NiMoO wafer arrays was elaborately fabricated via highly matched lattices for superior alkaline water electrolysis through optimizing the adsorption energies of the key intermediates at the interface based on synergistic electronic, geometric, and interfacial effects. The incorporation of Mo ion can adjust the electronic structure of host NiO x endowing the resultant NiMoO with suitable H and O intermediate binding energy for active species transfer between the interfaces. The ratio of O/C on the surface of flexible carbon cloth was well tuned through O 2 -plasma to achieve the desired geometric structure of NiMoO wafers with features of rich porosity and abundant active site. The RuO 2 nanoparticles are homogeneously distributed on the surface of porous NiMoO wafers via highly matched lattices, thereby offering efficient interfacial synergy. Consequently, the hybrid nanostructure of Ru species and NiMoO exhibits greatly enhanced bifunctional electrocatalytic activities toward both HER and OER for overall water splitting. The integrated NiMoO wafer works like a turbo for engineering robust Ru-based bifunctional electrocatalyst. The finding may provide insights for the rational design of advanced nanocomposite catalysts for various energy conversion applications. [ABSTRACT FROM AUTHOR]

• The patterned Ni@NCNTs/NF-L is prepared by laser processing and calcination reaction. • The Ni@NCNTs/NF-L serves as photothermal conversion layer and HER electrocatalyst. • Under light illumination, the voltage of Electrolyzer-TE is reduced dramatically. • A Self-drive Electrolyzer-TE hybrid device for water splitting has been realized. For efficient conversion from solar energy to hydrogen energy, the integrated system between light absorbing unit and water splitting unit is in the spotlight. Herein, we presented a bifunctional Ni@NCNTs/NF-L as both photothermal conversion layer integrated with thermoelectric generator (TE) and efficient hydrogen evolution reaction (HER) electrocatalyst to reducing the potential, realizing the integration system for overall water splitting. The Ni nanoparticles embedded into N -doped carbon nanotubes (Ni@NCNTs/NF-L) with various patterns are prepared by controllable laser processing and gas-solid calcination reaction. Furthermore, iron nickel oxides nanoparticles on NiFe alloys foil (NiFe-L) are obtained by laser ablation, which are applied for the oxygen evolution reaction (OER) electrode to establish two electrode electrolyzer of (−) Ni@NCNTs/NF-L/TE // NiFe-L (+) for overall water splitting. Integrating with one TE, the voltage of water splitting at the current-density of 50 mA cm−2 reduced from 1.947 V to 1.213 V under the standard AM 1.5 G illumination. The integrated thermoelectric device plays a doubtless role to realize solar energy driving overall water splitting with integration and patterning fabrication in large-scale. [ABSTRACT FROM AUTHOR]

• Photocatalysis of CdS/MoS 2 /Mo was improved by 89% in magnetic field. • In situ micro-potential drives photo-induced charge separation in suspension. • Hybrid nanostructure combines photocatalyst, co-catalyst and micro-potential. Building a persistently active potential in photocatalyst is always important but difficult for the high-performance photocatalysis. Based on the idea that electromagnetic induction effect can derive an in-situ micro-potential on a micro-conductor, a nanostructured hybrid CdS/MoS 2 /Mo photocatalyst is designed and synthesized by a one-step hydrothermal process. By replacing the commercial magnetic stirrer with the magnetic field strengthened one, the H 2 evolution efficiency of the CdS/MoS 2 /Mo hybrid microstructures is improved by 89% illuminated at 100 mW·cm−2 Xe lamp illumination. The in situ micro-potential in the metallic Mo sheet which is derived from the electromagnetic induction during the relative motion in the magnetic field should play the key role in the enhancement of the photocatalysis. This type of hybrid nanostructure can combine with the photocatalyst, the co-catalyst, and the carrier separation effect of the micro-potential, which can extend the application of the external field in the enhancement of photocatalytic performance, especially for magnetic field application with low extra energy consumption. [ABSTRACT FROM AUTHOR]

A new catalyst, atomic isolated Ru SAs on N-doped Mo 2 C NSs were fabricated by an anti-Ostwald ripening method (Ru SAs/N-Mo 2 C NSs), exhibited superior HER activity with a mass activity of 7-fold greater than that of 20 wt% Pt/C at an overpotential of 100 mV vs. RHE. • A simple and versatile anti-Ostwald ripening method was employed to fabricate the Ru SAs/N-Mo 2 C NSs. • The mass activity of Ru SAs/N-Mo 2 C NSs was 7-fold greater than 20 wt% Pt/C at an overpotential of 100 mV. • The Ru SAs/N-Mo 2 C NSs possessed the robust HER catalytic stability at high current densities. • The enhanced HER mechanism of the Ru SAs/N-Mo 2 C NSs was revealed by density function theory calculations. The irreversible sintering of supported ruthenium (Ru) catalyst in the preparation process has seriously affected its hydrogen evolution reaction (HER) activity and stability. Herein, ultrathin nitrogen-doped molybdenum carbide nanosheets (N-Mo 2 C NSs) is used as a versatile support to stabilize Ru single atoms (SAs) sites via the anti-Ostwald ripening. Ru SAs are dispersed into the N-Mo 2 C NSs matrix via the strong bonding between the Ru atoms and Mo 2 C NSs regulated by N doping. The atomic isolated Ru SAs are confirmed by spherical aberration correction transmission electron microscopy (AC HAADF-STEM) and X-ray absorption fine structure (XAFS) measurements. Ru SAs/N-Mo 2 C NSs exhibits outstanding HER performance, with a small overpotential of 43 mV at 10 mA/cm2, and robust catalytic stability in 1.0 M KOH. Importantly, Ru SAs/N-Mo 2 C NSs possesses a higher mass activity of 6.44 A/mg Ru than that of 20 wt% Pt/C (0.91 A/mg Pt) at the overpotential of 100 mV. Theoretical calculations further reveal that the high HER activity of Ru SAs/N-Mo 2 C NSs is derived from the synergistically accelerated the dissociation of H 2 O and the optimized H adsorption strength in Mo-Ru interface. This result provides a new direction for the rational designing monatomic electrocatalysts for HER via support interaction effect. [ABSTRACT FROM AUTHOR]

• A in-situ growth of CNTs strategy is used to trigger perovskite electrocatalysts. • The optimal perovskite exhibits a remarkably enhanced catalytic performance on HER. • The interaction between CNTs and perovskite modifies the electrochemical activity. The naturally scarce and costly precious metal as catalysts for electrochemical water electrolysis have prevent the large-scale applications in the transition of this technology. Therefore, it is emergency to explore for much cheaper and superior active scalable materials in making this technology to be more promising. The perovskite oxides, with rich constitutions and structures, can be easily to tune of the electrocatalytic applications by tailoring compositions. Herein, a highly efficient catalyst composed of nitrogen-doped carbon coated multi-metals core decorated Ruddlesden-Popper type structure (Pr 0.4 Sr 0.6) 3 (Fe 0.85 Nb 0.15) 2 O 7 (NC-CF-PSFN) compounds is synthesized via a in situ growth of carbon nanotubes treatment that trigger their catalytic activities. The optimal electrocatalyst exhibits a significantly enhanced electrocatalytic activity for hydrogen evolution reaction (HER) by affording an overpotential of 124 mV at the current density of 10 mA cm−2, an onset potential of –12 mV vs. RHE, accompanied by an outstanding durability in acidic media, outperforming that of perovskite-based catalysts. The optimized internal/external interaction between the complex carbon and perovskite phases would contribute to modify its electrochemical performance. This protocol highlights a novel strategy to prepare excellent perovskite materials for applications in energy generation and storage. [ABSTRACT FROM AUTHOR]

• Metallic Ni 3 Mo 3 N porous microrods showed a low overpotential of 44.6 mV to attain a current density of 10 mA cm−2 and superstability at a large current density of 1100 mA cm−2 for 50 h. • Density functional theory (DFT) calculations clarified that the Ni 3 Mo 3 N electrocatalyst possesses various HER catalytic active sites with suitable ΔG H* values (more than ten sites) due to the metallic semiconductor structure with special electronic structure. • The constructed NC/Ni 3 Mo 3 N/NF||NiMoO 4 ·xH 2 O/NF only needed a voltage of 1.58 V to attain a current density of 50 mA cm−2, which was better than that of 20 wt% Pt/C||RuO 2 (1.71 V), and has high potential for large-scale industrial applications. The low onset potential and large current density of electrocatalysts has always been important target for hydrogen evolution reaction (HER). In especial, the large current density (larger than 1000 mA cm−2) is an important criterion for the evaluation of electrocatalysts for industrial application. Usually, the number of catalytic sites in electrocatalyst limits the current density for HER. To overcome these problems, bimetallic nitride is controllably synthesized, and the corresponding catalytic sites are regulated by a bimetallic effect. Herein, an inexpensive electrocatalyst consisting of N-doped carbon-coated porous Ni 3 Mo 3 N microrods (NC/Ni 3 Mo 3 N/NF) is cultured on nickel foam using a hydrothermal reaction and subsequent nitriding process. The designed electrocatalyst consisting of porous NC/Ni 3 Mo 3 N microrods displays efficient catalytic activity for hydrogen evolution reaction (HER), with a small overpotential of 136 mV to achieve a cathodic current density of 100 mA cm−2. Density functional theory (DFT) calculations clarified that the Ni 3 Mo 3 N electrocatalyst possesses various HER catalytic active sites with suitable ΔG H* values (more than ten sites) due to the metallic semiconductor structure with special electronic structure. It is important that NC/Ni 3 Mo 3 N/NF possess perfect superstability for HER, with a large current density of 1100 mA cm−2 for 50 h. Lastly, NC/Ni 3 Mo 3 N/NF and NiMoO 4 ·xH 2 O/NF are hired as the cathode and anode, respectively, to assemble the two-electrode electrolytic cell, thereby achieving excellent overall water splitting performance with a voltage of 1.58 V at 50 mA cm−2 in 1 M KOH aqueous solution. [ABSTRACT FROM AUTHOR]

• Saccharomycetes are used as green phosphorus source to produce metal phosphides. • Interface phosphating for solid-solid contact can efficiently utilize phosphorus. • Graphitizing & migration of metal-catalyzed carbon matrix to form hollow structure. • The Ni/Ni 3 P heterostructure can weaken strong Ni–H bonding to obtain small Δ G H*. • Achieve hydrogen production from wastewater treatment at low input voltages. The development of new, clean and efficient catalytic materials for hydrogen evolution reaction (HER) has become extremely unstoppable. Herein, the heterostructural Ni-Ni 3 P nanoparticles embedded into N\P co-doped carbon shells on 3D graphene frameworks (Ni-Ni 3 P@NPC/rGO) was synthesized via an in situ phosphatization of nickel well-integrated with the structure engineering of carbon matrix derived from saccharomycetes. The in-situ phosphating process of nickel using P source provided by saccharomycetes is particularly simple, economical and environmentally friendly. In addition, the as-prepared Ni-Ni 3 P@NPC/rGO exhibits superior bifunctional electrocatalytic performance toward both HER (extremely low overpotential of 113 mV at 20 mA cm–2) and urea degradation reaction (UDR, only 1.38 V to attain 50 mA cm–2). Furthermore, a two-electrode electrolyzer employing the 3D block electrode (Ni-Ni 3 P@NPC/rGO/GFB) couple on both cathode and anode, can produce higher current density with lower voltage in urea-based wastewater splitting less than pure water splitting (saved 448 mV to deliver 500 mA g–1). [ABSTRACT FROM AUTHOR]