Vacancy Ordering in Ultrathin Copper Oxide Films on Cu(111).

Oxide thin films grown on metal surfaces have wide applications in catalysis and beyond owing to their unique surface structures compared to their bulk counterparts. Despite extensive studies, the atomic structures of copper surface oxides on Cu(111), commonly referred to as "44" and "29", have remained elusive. In this work, we demonstrated an approach for the structural determination of oxide surfaces using element-specific scanning tunneling microscopy (STM) imaging enhanced by functionalized tips. This approach enabled us to resolve the atomic structures of "44" and "29" surface oxides, which were further corroborated by noncontact atomic force microscopy (nc-AFM) measurements and Monte Carlo (MC) simulations. The stoichiometry of the "44" and "29" frameworks was identified as Cu23O16 and Cu16O11, respectively. Contrary to the conventional hypothesis, we observed ordered Cu vacancies within the "44" structure manifesting as peanut-shaped cavities in the hexagonal lattice. Similarly, a combination of Cu and O vacancies within the "29" structure leads to bean-shaped cavities within the pentagonal lattice. Our study has thus resolved the decades-long controversy on the atomic structures of "44" and "29" surface oxides, advancing our understanding of copper oxidation processes and introducing a robust framework for the analysis of complex oxide surfaces.

Targeting AQP9 enhanced the anti-TNF therapy response in Crohn's disease by inhibiting LPA-hippo pathway.

Although anti-TNF antibodies are extensively used to treat Crohn's disease (CD), a significant proportion of patients, up to 40%, exhibit an inadequate response to this therapy. Our objective was to identify potential targets that could improve the effectiveness of anti-TNF therapy in CD. Through the integration and analysis of transcriptomic data from various CD databases, we found that the expression of AQP9 was significantly increased in anti-TNF therapy-resistant specimens. The response to anti-TNF therapy in the CD mouse model was significantly enhanced by specifically inhibiting AQP9. Further experiments found that the blockade of AQP9, which is dominantly expressed in macrophages, decreased inflamed macrophage functions and cytokine expression. Mechanistic studies revealed that AQP9 transported glycerol into macrophages, where it was metabolized to LPA, which was further metabolized to LPA, resulting in the activation of the LPAR2 receptor and downstream hippo pathway, finally promoting the expression of cytokines, especially IL23 and IL1ß⊡ Taken together, the expansion of AQP9+ macrophages is associated with resistance to anti-TNF therapy in Crohn's disease. These findings indicated that AQP9 could be a potential target for enhancing anti-TNF therapy in Crohn's disease.

The "Pull Effect" of a Hanging ZnII on Improving the Four-Electron Oxygen Reduction Selectivity with Co Porphyrin.

Due to the challenge of cleaving O-O bonds at single Co sites, mononuclear Co complexes typically show poor selectivity for the four-electron (4e-) oxygen reduction reaction (ORR). Herein, we report on selective 4e- ORR catalyzed by a Co porphyrin with a hanged ZnII ion. Inspired by Cu/Zn-superoxide dismutase, we designed and synthesized 1-CoZn with a hanging ZnII at the second sphere of a Co porphyrin. Complex 1-CoZn is much more effective than its Zn-lacking analogues to catalyze the 4e- ORR in neutral aqueous solutions, giving an electron number of 3.91 per O2 reduction. With spectroscopic studies, the hanging ZnII was demonstrated to be able to facilitate the electron transfer from CoII to O2, through an electronic "pull effect", to give CoIII-superoxo. Theoretical studies further suggested that this "pull effect" plays crucial roles in assisting O-O bond cleavage. This work is significant to present a new strategy of hanging a ZnII to improve O2 activation and O-O bond cleavage.

Anchoring Fe Species on the Highly Curved Surface of S and N Co-Doped Carbonaceous Nanosprings for Oxygen Electrocatalysis and a Flexible Zinc-Air Battery.

Oxygen reduction reaction (ORR) is of critical significance in the advancement of fuel cells and zinc-air batteries. The iron-nitrogen (Fe-Nx ) sites exhibited exceptional reactivity towards ORR. However, the task of designing and controlling the local structure of Fe species for high ORR activity and stability remains a challenge. Herein, we have achieved successful immobilization of Fe species onto the highly curved surface of S, N co-doped carbonaceous nanosprings (denoted as FeNS/Fe3 C@CNS). The induction of this twisted configuration within FeNS/Fe3 C@CNS arose from the assembly of chiral templates. For electrocatalytic ORR tests, FeNS/Fe3 C@CNS exhibits a half-wave potential (E1/2 ) of 0.91 V in alkaline medium and a E1/2 of 0.78 V in acidic medium. The Fe single atoms and Fe3 C nanoparticles are coexistent and play as active centers within FeNS/Fe3 C@CNS. The highly curved surface, coupled with S substitution in the coordination layer, served to reduce the energy barrier for ORR, thereby enhancing the intrinsic catalytic activity of the Fe single-atom sites. We also assembled a wearable flexible Zn-air battery using FeNS/Fe3 C@CNS as electrocatalysts. This work provides new insights into the construction of highly curved surfaces within carbon materials, offering high electrocatalytic efficacy and remarkable performance for flexible energy conversion devices.

Creating and Stabilizing an Oxidized Pd Surface under Reductive Conditions for Photocatalytic Hydrogenation of Aromatic Carbonyls.

Photocatalysis provides an eco-friendly route for the hydrogenation of aromatic carbonyls to O-free aromatics, which is an important refining process in the chemical industry that is generally carried out under high pressure of hydrogen at elevated temperatures. However, aromatic carbonyls are often only partially hydrogenated to alcohols, which readily desorbs and are hardly further deoxygenated under ambient conditions. Here, we show that by constructing an oxide surface over the Pd cocatalyst supported on graphitic carbon nitride, an alternative hydrogenation path of aromatic carbonyls becomes available via a step-wise acetalization and hydrogenation, thus allowing efficient and selective production of O-free aromatics. The PdO surface allows for optimum adsorption of reactants and intermediates and rapid abstraction of hydrogen from the alcohol donor, favoring fast acetalization of the carbonyls and their consecutive hydrogenation to O-free hydrocarbons. The photocatalytic hydrogenation of benzaldehyde into toluene shows a high selectivity of >90% and a quantum efficiency of ∼10.2% under 410 nm irradiation. By adding trace amounts of HCl to the reaction solution, the PdO surface remains stable and active for long-term operation at high concentrations, offering perspective for practical applications.

Chiral Carbon Dots Derived from Serine with Well-Defined Structure and Enantioselective Catalytic Activity.

Carbon dots (C-Dots), with unique properties from tunable photoluminescence to biocompatibility, show wide applications in biotechnology, optoelectronic device and catalysis. Chiral C-Dots are expected to have strongly chirality-dependent biological and catalytic properties. For chiral C-Dots, a clear structure and quantitative structure-property relationship need to be clarified. Here, chiral C-Dots were fabricated by electrooxidation polymerization from serine enantiomers. The oxidized serine has a reversed chiral configuration to serine, which leads to the chiral C-Dots possessing inverse handedness compared with their raw materials. Electron circular dichroism spectrum, together with other diverse characterization techniques and theoretical calculations, confirmed that these chiral C-Dots (2-7 nm) have a well-defined primary structure of polycyclic dipeptide and possess a spatial structure with a c-axis of hexagonal symmetry and two cyclic dipeptides as the spatial structural unit. These chiral C-Dots also show enantioselective catalytic activity on DOPA enantiomers oxidation.

High Valence State Sites as Favorable Reductive Centers for High-Current-Density Water Splitting.

Electrochemical water splitting is a promising approach for producing sustainable and clean hydrogen. Typically, high valence state sites are favorable for oxidation evolution reaction (OER), while low valence states can facilitate hydrogen evolution reaction (HER). However, here we proposed a high valence state of Co3+ in Ni9.5 Co0.5 -S-FeOx hybrid as the favorable center for efficient and stable HER, while structural analogues with low chemical states showed much worse performance. As a result, the Ni9.5 Co0.5 -S-FeOx catalyst could drive alkaline HER with an ultra-low overpotential of 22 mV for 10 mA cm-2 , and 175 mV for 1000 mA cm-2 at the industrial temperature of 60 °C, with an excellent stability over 300 h. Moreover, this material could work for both OER and HER, with a low cell voltage being 1.730 V to achieve 1000 mA cm-2 for overall water splitting at 60 °C. X-ray absorption spectroscopy (XAS) clearly identified the high valence Co3+ sites, while in situ XAS during HER and theoretical calculations revealed the favorable electron capture at Co3+ and suitable H adsorption/desorption energy around Co3+ , which could accelerate the HER. The understanding of high valence states to drive reductive reactions may pave the way for the rational design of energy-related catalysts.

Influence of Molecular Configurations on the Desulfonylation Reactions on Metal Surfaces.

On-surface synthesis is a powerful methodology for the fabrication of low-dimensional functional materials. The precursor molecules usually anchor on different metal surfaces via similar configurations. The activation energies are therefore solely determined by the chemical activity of the respective metal surfaces. Here, we studied the influence of the detailed adsorption configuration on the activation energy on different metal surfaces. We systematically studied the desulfonylation homocoupling for a molecular precursor on Au(111) and Ag(111) and found that the activation energy is lower on inert Au(111) than on Ag(111). Combining scanning tunneling microscopy observations, synchrotron radiation photoemission spectroscopy measurements, and density functional theory calculations, we elucidate that the phenomenon arises from different molecule-substrate interactions. The molecular precursors anchor on Au(111) via Au-S interactions, which lead to weakening of the phenyl-S bonds. On the other hand, the molecular precursors anchor on Ag(111) via Ag-O interactions, resulting in the lifting of the S atoms. As a consequence, the activation barrier of the desulfonylation reactions is higher on Ag(111), although silver is generally more chemically active than gold. Our study not only reports a new type of on-surface chemical reaction but also clarifies the influence of detailed adsorption configurations on specific on-surface chemical reactions.

External validation of different difficulty scoring systems of laparoscopic liver resection for hepatocellular carcinoma.

BACKGROUND: Several difficulty scoring systems (DSSs) have been proposed for evaluating difficulty of laparoscopic liver resection (LLR) and no study has validated their performance in a hepatocellular carcinoma (HCC)-only cohort at the same time. METHODS: All cases with HCC that underwent LLR from January 2015 to December 2020 in our center were retrospectively collected. Performance of the IWATE-DSS, Halls-DSS, Hasegawa-DSS, and Kawaguchi-DSS in predicting perioperative outcomes was evaluated. Subgroup analyses were conducted to compare perioperative outcomes between surgeons on the learning curve and surgeons that have gone through the learning curve. RESULTS: For all four DSSs, there were significant distributions of applying bleeding control, surgical time, estimated blood loss, postoperative major complications, and postoperative hospital stay among different groups of each DSS (P all < 0.05). Conversion to laparotomy or not was significantly distributed in different groups of the IWATE-DSS (P = 0.006) and Halls-DSS (P = 0.022), while it was not in the Hasegawa-DSS (P = 0.056) and Kawaguchi-DSS (P = 0.183). Trend tests showed that the conversion rates increased with higher DSS points in the IWATE-DSS (P < 0.001) and the Kawaguchi-DSS (P = 0.021), while not in the Halls-DSS (P = 0.064) and the Hasegawa-DSS (P = 0.068). In the medium and advanced/expert difficulty-level subgroups defined by the IWATE-DSS, there were larger estimated blood loss (P in medium-difficulty group = 0.009; P in the advanced/expert difficulty group = 0.004) and longer postoperative hospital stay (P in the medium-difficulty group = 0.012; P in the advanced/expert group = 0.035) in the learner-performed cases. CONCLUSIONS: All DSSs performed well in predicting applying bleeding control, surgical time, estimated blood loss, postoperative major complications, and postoperative hospital stay, while only the IWATE-DSS was able to predict whether conversion to laparotomy or not for HCC patients underwent LLR. The IWATE-DSS was also able to help surgeons on the LLR learning curve choose cases and guide clinical practices.

Estrogen receptor-negative/progesterone receptor-positive and her-2-negative breast cancer might no longer be classified as hormone receptor-positive breast cancer.

BACKGROUND: The single progesterone receptor (PR)-positive phenotype (estrogen receptor (ER)-/PR + , sPR positive) is an infrequent and independent biological entity. However, the prognosis of patients with sPR-positive and her-2-negative phenotype is still controversial, and it is not always easy to decide treatment strategies for them. METHODS: Patients during 2010-2014 were identified from Surveillance, Epidemiology, and End Results (SEER) database. The Kaplan-Meier method was used to evaluate cancer-specific survival (CSS). The propensity score matching (PSM) method was used to balance differences of characteristics in groups. The Life-Table method was used to calculate 5-year CSS rates and the annual hazard rate of death (HRD). RESULTS: A total of 97,527 patients were included, and only 745 (0.76%) patients were sPR-positive phenotype. The majority of sPR-positive breast cancer were basal-like subtype. Survival analysis showed that the sPR-positive breast cancer had similar prognosis comparing to double hormonal receptor-negative (ER-/PR-, dHoR-negative) breast cancer, and had the highest HRD during the initial 1-2 years of follow-up, then maintained the HRD of almost zero during the late years of follow-up. CONCLUSIONS: The patients with sPR-positive and her-2-negative breast cancer, similar to dHoR-negative breast cancer, had a worse survival, and could benefit from chemotherapy significantly. However, the escalating endocrine therapy was not recommended for sPR-positive patients. The patients with sPR positive should be excluded from future clinical trials concerning endocrine therapy.

First report of Taxus media branch blight caused by Neopestalotiopsis clavispora in China.

Taxus media Rehder is a high-value tree species and can be used for landscape afforestation and medicinal purposes considering its beautiful shape and secondary metabolite paclitaxel. In May 2019, branch blight of T. media was observed in plantations in Hangzhou, Zhejiang province, China. The lesions were brown, necrotic and sunken, and the branches were withering. Plants from five plantations were surveyed, and the disease incidence was 60%. Necrotic tissues from 5 plans from each plantation were cut into small pieces (5×5 mm), surface disinfected with 75% alcohol for 30 s and 2% sodium hypochlorite solution for 2-3 min, washed twice with sterile water, then dried on sterile filter paper. Branch pieces were aseptically transferred to potato dextrose agar (PDA) plates and incubated at 25℃ in the dark for 3 days. Five purified fungal cultures were obtained and the representative isolate (LA-01) that grew slightly more vigorously under the same condition was selected for morphological characterization and DNA sequence comparison. The colony was initially white and cottony, with circular growth, undulated edge, wavy surface and pale beige on the back. The conidia were long spindle-shaped, straight or slightly curved, 21-27 × 6-8 µm (n=50) in overall shape. They contained 5 cells with those at the apex and base hyaline. The second and third cells from the apex were darker (brown) than the fourth cell from the apex (pale brown). Two or three (most frequently observed) hyaline appendages were apparent at the apex, 16-31 µm in length. Morphological characteristics of the obtained isolate were consistent with those in the genus of Neopestalotiopsis (Solart et al. 2018). DNA of LA-01 was extracted from fresh mycelia using Minibest Universal Genomic DNA Extraction Kit (Takara, Toyoto, Japan) according to the manufacturer's instructions. The partial regions from the internal transcribed spacer (ITS), ß-tubulin gene (TUB2), and translation elongation factor subunit 1-a gene (TEF1) were amplified and sequenced using universal primer pairs ITS5/ITS4, BT2A/BT2B, and EF1-526F/EF1-1567R (Maharachchikumbura et al. 2012), respectively. The resulting nucleotide sequences were individually subjected to BLAST searches in GenBank. The nucleotide sequences of ITS (MZ148633, 554 bp), TUB2 (MZ286974, 473 bp ), TEF1 (MZ286975, 1030 bp) of the isolate LA-01 showed 99.64% similarity to ITS sequence (MW512858.1), 99.35% similarity to TUB2 sequence (MH423961.1), 98.18% similarity to TEF1 sequence (KU096881.1). The multi-locus phylogenetic tree was constructed based on the combined ITS-TUB2-TEF1 sequences using MEGA 7 using the neighbor-joining method, indicating that LA-01 represents Neopestalotiopsis clavispora. Inoculation was done on branches of ten T. media plants in the field to verify the pathogenicity of LA-01. Two healthy branches of each plant were surface sterilized with 75% ethanol allowed to dry, and two small wounds on each branch were obtained by puncturing with a sterilized needle. One wound was inoculated with 5-mm-diameter PDA discs excised from 7-day-old cultures, and wrapped with parafilm; the other inoculated with sterile PDA plugs as control, and wrapped with parafilm. Disease symptoms developed on all N. clavispora-inoculated wounds 3 days after inoculation. The yellow brown lesions became apparent 20 days later, whereas the control wounds remained asymptomatic. The fungus N. clavispora was reisolated from the diseased lesions using the same methods above, fulfilling Koch's postulates. Previously, the species was reported to cause leaf spot disease on another Taxus tree species T. chinensis in China (Wang et al. 2019). This is the first report of T. media branch blight caused by N. clavispora worldwide. Special attention should be paid to the damage it may cause to T. media producers, and precautionary monitoring on T. media population will be a significant part of the conservation efforts in China.

Intracorporeal reinforcement with barbed suture is associated with low anastomotic leakage rates after laparoscopic low anterior resection for rectal cancer: a retrospective study.

BACKGROUND: Anastomotic leakage (AL) is one of most severe postoperative complications following low anterior resection (LAR) for rectal cancer, and has an adverse impact on postoperative recovery. The occurence of AL is associated with several factors, while few studies explored the role of intracorporeal barbed suture reinforcement in it. METHODS: Consecutive cases underwent laparoscopic LAR for rectal cancer from Mar. 2018 to Feb. 2021 in our center were retrospectively collected. Cases were classified into the intracorporeal barbed suture reinforcement group and the control group according to whether performing intracorporeal reinforcement with barbed suture, and AL incidences were compared between two groups. Propensity score matching (PSM) was then performed based on identified risk factors to reduce biases from covariates between two groups. AL incidences in the matched cohort were compared. RESULTS: A total of 292 cases entered into the study, and AL incidences were significantly lower in the intracorporeal barbed suture reinforcement group compared with the control group (10.00% vs 2.82%, P = 0.024). Sex, BMI, preoperative adjuvant chemoradiotherapy and anastomotic level were chose for PSM analyses based on previous studies. In the matched cohort, the AL incidences were still significantly lower in the intracorporeal barbed suture reinforcement group (10.57% vs 2.44%, SD = 0.334). CONCLUSIONS: Intracorporeal barbed suture reinforcement is associated with low AL incidences after laparoscopic LAR for rectal cancer, which is a potential procedure for reducing AL and worthy of application clinically.

Two-Dimensional Palladium-Copper Alloy Nanodendrites for Highly Stable and Selective Electrochemical Formate Production.

Pd is the only metal that can catalyze electrochemical CO2 reduction to formate at close-to-zero overpotential. It is unfortunately subjected to severe poisoning by trace CO as the side product and suffers from deteriorating stability and selectivity with increasing overpotential. Here, we demonstrate that alloying Pd with Cu in the form of two-dimensional nanodendrites could enable highly stable and selective formate production. Such unique bimetallic nanostructures are formed as a result of the rapid in-plane growth and suppressed out-of-plane growth by carefully controlling a set of experimental parameters. Thanks to the combined electronic effect and nanostructuring effect, our alloy product catalyzes CO2 reduction to formate with remarkable stability and selectivity under the working potential as cathodic as -0.4 V. Our results are rationalized by computational simulations, evidencing that Cu atoms weaken the *CO adsorption and stabilize the *OCHO adsorption on neighboring Pd atoms.

Electronic Modulation of Hierarchical Spongy Nanosheets toward Efficient and Stable Water Electrolysis.

The energy conversion efficiency of water electrolysis is determined by the activity of selected catalysts. Ideal catalysts should possess not only porous architecture for high-density assembly of active sites but also a subtle electronic configuration for the optimized activity at each site. In this context, the development of stable porous hosting materials that allow the incorporation of various metal elements is highly desirable for both experimental optimization and theoretical comparison/prediction. Herein, MOF-derived spongy nanosheet arrays constructed by assembly of carbon encapsulated hetero-metal doped Ni2 P nanoparticles is presented as a superior bifunctional electrocatalyst for water splitting. This hierarchical structure can be stably retained when secondary metal dopants are introduced, providing a flexible platform for electronic modulation. The catalytic origin of activity enhancement via metal (Fe, Cr, and Mn) doping is deciphered through experimental and theoretical investigations. Combining the advantages in both morphological and electronic structures, the optimized catalyst NiMn-P exhibits remarkable activity in both hydrogen and oxygen evolution in the alkaline media, with an ultrasmall cell voltage of 1.49 V (at 10 mA cm-2 ) and high durability for at least 240 h.

Bamboo Tar as a Novel Fungicide: Its Chemical Components, Laboratory Evaluation, and Field Efficacy Against False Smut and Sheath Blight of Rice and Powdery Mildew and Fusarium Wilt of Cucumber.

The application of agricultural and forest residues can benefit the environment and the economy; however, they also generate a large amount of byproducts. In this study, bamboo tar (BT), a waste product of bamboo charcoal production, was dissolved in natural ethanol and the surfactant alkyl glucoside to manufacture a 50% (wt/wt) BT emulsifiable concentrate (BTEC) biopesticide. BTEC was screened for fungicidal activity against pathogens. The greatest activity was seen against Ustilaginoidea virens with a half-maximal effective concentration (EC50) value of 6 mg/liter. Four phytopathogenic fungi, Podosphaera xanthii, Rhizoctonia solani, Fusarium oxysporum, and Botrytis cinerea, showed EC50 values of <60 mg/liter. Greenhouse tests in vivo showed 2,000 mg/liter BTEC had a 78.4% protective effect against U. virens, and replicated treatments had an 80.6% protective effect. In addition, replicated 2-year field trials were conducted in two geographic locations with four plant diseases: false smut (U. virens), rice sheath blight (Thanatephorus cucumeris [Frank] Donk), cucumber powdery mildew (P. xanthii), and cucumber Fusarium wilt (F. oxysporum). Results showed that 1,000 to 2,000 mg/liter BTEC significantly inhibited these diseases. Gas chromatography-mass spectrometry analysis showed that the total phenolic mass fractions of two BT samples were 45.39 and 48.26%. Eleven components were detected, and their percentage content was as follows (from high to low): 2,6-dimethoxyphenol > 2- or 4-ethylphenol > 2- or 4-methylphenol > phenol > 4-ethylguaiacol > dimethoxyphenol > 4-methylguaiacol > 4-propenyl-2,6-dimethoxyphenol > 2,4-dimethylphenol. Some of the phenolic compounds identified from the tar might be fungicidally active components. BT is a biochar waste, which has potential as a biofungicide and has promise in organic agriculture. The value of this tar may not be because of any fundamental physical differences from other synthetic fungicides but rather caused by reduced production expenses and more efficient use of waste products.

Revealing the Correlation between Catalytic Selectivity and the Local Coordination Environment of Pt Single Atom.

Single atom catalysts (SACs) have recently attracted great attention in heterogeneous catalysis and have been regarded as ideal models for investigating the strong interaction between metal and support. Despite the huge progress over the past decade, the deep understanding on the structure-performance correlation of SACs at a single atom level still remains to be a great challenge. In this study, we demonstrate that the variation in the coordination number of the Pt single atom can significantly promote the propylene selectivity during propyne semihydrogenation (PSH) for the first time. Specifically, the propylene selectivity greatly increases from 65.4% to 94.1% as the coordination number of Pt-O increases from ∼3.4 to ∼5, whereas the variation in the coordination number of Pt-O slightly influences the turnover frequency values of SACs. We anticipate that the present work may deepen the understanding on the structure-performance of SACs and also promote the fundamental research in single atom catalysis.

Highly Curved Nanostructure-Coated Co, N-Doped Carbon Materials for Oxygen Electrocatalysis.

Nitrogen-doped graphene could catalyze the electrochemical reduction and evolution of oxygen, but unfortunately suffers from sluggish catalytic kinetics. Herein, for the first time, we report an onion-like carbon coated Co, N-doped carbon (OLC/Co-N-C) material, which possesses multilayers of highly curved nanostructures that form mesoporous architectures. These unique nanospheres are produced when surfactant micelles are introduced to synthesis precursors. Owing to the combined electronic effect and nanostructuring effect, our OLC/Co-N-C materials exhibit high bifunctional oxygen reduction/evolution reaction (ORR/OER) activity, showing a promising application in rechargeable Zn-air batteries. Experimental results are rationalized by theoretical calculations, showing that the curvature of graphitic carbon plays a vital role in promoting activities of meta-carbon atoms near graphitic N and ortho/meta carbon atoms close to pyridinic N.

Regulating the Local Charge Distribution of Ni Active Sites for the Urea Oxidation Reaction.

In electrochemical energy storage and conversion systems, the anodic oxygen evolution reaction (OER) accounts for a large proportion of the energy consumption. The electrocatalytic urea oxidation reaction (UOR) is one of the promising alternatives to OER, owing to its low thermodynamic potential. However, owing to the sluggish UOR kinetics, its potential in practical use has not been unlocked. Herein, we developed a tungsten-doped nickel catalyst (Ni-WOx ) with superior activity towards UOR. The Ni-WOx catalyst exhibited record fast reaction kinetics (440 mA cm-2 at 1.6 V versus reversible hydrogen electrode) and a high turnover frequency of 0.11 s-1 , which is 4.8 times higher than that without W dopants. In further experiments, we found that the W dopant regulated the local charge distribution of Ni atoms, leading to the formation of Ni3+ sites with superior activity and thus accelerating the interfacial catalytic reaction. Moreover, when we integrated Ni-WOx into a CO2 flow electrolyzer, the cell voltage is reduced to 2.16 V accompanying with ≈98 % Faradaic efficiency towards carbon monoxide.

Bond-Scission-Induced Structural Transformation from Cumulene to Diyne Moiety and Formation of Semiconducting Organometallic Polyyne.

The structural transformation from symmetric cumulene to broken-symmetry polyyne within a one-dimensional (1-D) atomic carbon chain is a signature of Peierls distortion. Direct observation of such a structural transformation with single-bond resolution is, however, still challenging. Herein, we design a molecule with a cumulene moiety (Br2C═C═C═CBr2) and employ STM tip manipulation to achieve the molecular skeleton rearrangement from a cumulene to a diyne moiety (Br-C≡C-C≡C-Br). Furthermore, by an on-surface reaction strategy, thermally induced entire debromination (:C═C═C═C:) leads to the formation of a 1-D organometallic polyyne (-C≡C-C≡C-Au-) with a semiconducting characteristic, which implies that a Peierls-like transition may occur in a rationally designed molecular system with limited length.

Hydrochromic CsPbBr3 Nanocrystals for Anti-Counterfeiting.

Hydrochromic materials that can reversibly change color upon water treatment have attracted much attention owing to their potential applications in diverse fields. Herein, for the first time, we report that space-confined CsPbBr3 nanocrystals (NCs) are hydrochromic. When CsPbBr3 NCs are loaded into a porous matrix, reversible transition between luminescent CsPbBr3 and non-luminescent CsPb2 Br5 can be achieved upon the exposure/removal of water. The potential applications of hydrochromic CsPbBr3 NCs in anti-counterfeiting are demonstrated by using CsPbBr3 NCs@mesoporous silica nanospheres (around 100 nm) as the starting material. Owing to the small particle size and negatively charged surface, the as-prepared particles can be laser-jet printed with high precision and high speed. We demonstrate the excellent stability over repeated transformation cycles without color fade. This new discovery may not only deepen the understanding of CsPbX3 , but also open a new way to design CsPbX3 materials for new applications.