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Abstract Efficient catalysis of ammonia borane (AB) holds potential for realizing controlled energy release from hydrogen fuel and addressing cost challenges faced by hydrogen storage. Here, we report that amorphous domains on metallic Fe crystal structures (R-Fe2O3 Foam) can achieve AB catalytic performances and stability (turnover frequency (TOF) of 113.6 min−1, about 771 L H2 in 900 h, and 43.27 mL/(min·cm2) for 10×10 cm2 of Foam) that outperform reported benchmarks (most

Abstract Carbon-based metal-free catalysts are promising green catalysts for photocatalysis and electrocatalysis due to their low cost and environmental friendliness. A key challenge in utilizing these catalysts is identifying their active sites, given their poor crystallinity and complex structures. Here we demonstrate the key structure of the double-bonded conjugated carbon group as a metal-free active site, enabling efficient O2 photoreduction to H2O2 through a cascaded water oxidation − O2 reduction process. Using ethylenediaminetetraacetic acid as a precursor, we synthesized various carbon-based photocatalysts and analyzed their structural evolution. Under the polymerization conditions of 260 °C to 400 °C, an N-ethyl-2-piperazinone-like structure was formed on the surface of the catalyst, resulting in high photocatalytic H2O2 photoproduction (2884.7 μmol g−1h−1) under visible light. A series of control experiments and theoretical calculations further confirm that the double-bond conjugated carbonyl structure is the key and universal feature of the active site of metal-free photocatalysts.

Abstract The coupled green energy and chemical production by photocatalysis represents a promising sustainable pathway, which poses great challenges for the multifunction integration of catalytic systems. Here we show a promising green photocatalyst design using Cu-ZnIn2S4 nanosheets and carbon dots as building units, which enables the integration of reaction, mass transfer, and separation functions in the nano-space, mimicking a nanoreactor. This function integration results in great activity promotion for benzyl alcohol oxidation coupled H2 production, with H2/benzaldehyde production rates of 45.95/46.47 mmol g−1 h−1, 36.87 and 36.73 times to pure ZnIn2S4, respectively, owning to the enhanced charge accumulation and mass transfer according to in-situ spectroscopies and computational simulations of the built-in electrical field. Near-unity selectivity of benzaldehyde is achieved via the effective separation enabled by the Cu(II)-mediated conformation flipping of the intermediates and subsequent π-π conjugation. This work demonstrates an inspiring proof-of-concept nanoreactor design of photocatalysts for coupled sustainable systems.

AbstractEutrema deltoideum (Hook. f. et Thoms.) has been recognized as a potentially important vegetable and medicinal resource. In this study, we present the complete chloroplast genome of E. deltoideum and conduct a phylogenetic analysis. The chloroplast genome is 154,051 bp long and consists of a large single-copy (LSC) region of 84,149 bp, two inverted repeat (IR) regions of 26,065 bp each, and a small single-copy (SSC) region of 17,772 bp. It contains 132 complete genes, including 87 protein-coding genes, 8 ribosomal RNA genes, and 37 tRNA genes. Additionally, we identified 78 simple sequence repeats (SSRs). The phylogenetic tree reveals that E. deltoideum is closely related to E. heterophyllum, and the Eutrema genus is monophyletic. This study provides valuable information about E. deltoideum and enhances our understanding of its taxonomic classification.

A unique optimized of core–shell structural B4C nanopowder, sintering aid additive of Si, and high-pressure sintering technique has been used to process nanocrystalline B4C–SiC ceramics with enhanced mechanical properties. C-coated B4C nanopowder was initially uniformly mixed with micron Si of different content by ball-milling. B4C–SiC composites with a homogenous distribution of SiC in B4C matrix were subsequently obtained by sintering the mixed powders at 6 GPa and 1600 °C. The added Si reacted with submicron amorphous carbon layer and amorphous carbon nanoshell to form dispersed SiC nanocrystals and Si–C phase filled at B4C grain boundaries and pores, respectively. The prepared composite had the most outstanding mechanical properties when the Si content in the precursor was 15 wt%, with a hardness reaching 37.8 GPa and a fracture toughness reaching 7.3 MPa·m1/2. Microstructural characterizations indicated that the multi deflection of nanoscale crack caused by intergranular fracture, the covalent bonding of Si–C phase at the grain boundary, and the abundant nanotwin substructure were jointly responsible for the superior performance in hardness and fracture toughness.

Abstract Despite the accumulating evidence linking the development of Alzheimer’s disease (AD) to the aggregation of Aβ peptides and the emergence of Aβ oligomers, the FDA has approved very few anti-aggregation-based therapies over the past several decades. Here, we report the discovery of an Aβ peptide aggregation inhibitor: an ultra-small nanodot called C3N. C3N nanodots alleviate aggregation-induced neuron cytotoxicity, rescue neuronal death, and prevent neurite damage in vitro. Importantly, they reduce the global cerebral Aβ peptides levels, particularly in fibrillar amyloid plaques, and restore synaptic loss in AD mice. Consequently, these C3N nanodots significantly ameliorate behavioral deficits of APP/PS1 double transgenic male AD mice. Moreover, analysis of critical tissues (e.g., heart, liver, spleen, lung, and kidney) display no obvious pathological damage, suggesting C3N nanodots are biologically safe. Finally, molecular dynamics simulations also reveal the inhibitory mechanisms of C3N nanodots in Aβ peptides aggregation and its potential application against AD.

Abstract The oxygen evolution reactions in acid play an important role in multiple energy storage devices. The practical promising Ru-Ir based catalysts need both the stable high oxidation state of the Ru centers and the high stability of these Ru species. Here, we report stable and oxidative charged Ru in two-dimensional ruthenium-iridium oxide enhances the activity. The Ru0.5Ir0.5O2 catalyst shows high activity in acid with a low overpotential of 151 mV at 10 mA cm−2, a high turnover frequency of 6.84 s−1 at 1.44 V versus reversible hydrogen electrode and good stability (618.3 h operation). Ru0.5Ir0.5O2 catalysts can form more Ru active sites with high oxidation states at lower applied voltages after Ir incorporation, which is confirmed by the pulse voltage induced current method. Also, The X-ray absorption spectroscopy data shows that the Ru-O-Ir local structure in two-dimensional Ru0.5Ir0.5O2 solid solution improved the stability of these Ru centers.

Highlights A bimetallic lanthanum-nickel oxysulfide based on a La2O2S prototype was developed as a precatalyst for the electrochemical alkaline oxygen evolution reaction (OER). The in situ, ex situ, and theoretical investigations demonstrated that the precatalyst underwent a deep OER-driven reconstruction into a porous heterostructure where NiOOH nanodomains were uniformly separated and confined by La(OH)3 barrier. Oxyanion (SO4 2−) was steadily adsorbed on the surface of this in situ reconstructed NiOOH/La(OH)3 heterostructure, enabling it for enhanced OER activity and durability.

Well-defined metastable phase nanostructures are a core issue for catalyst design. Here, the authors report metastable monoclinic phase IrO2 nanoribbons obtained via a molten-alkali mechanochemical method, which exhibit intrinsic high performance towards the acidic oxygen evolution reaction.

The construction of well-ordered nanoarrays, particularly invoking metastable material phases, remains a challenge. Here, authors prepared a well-ordered, rhodium nanoarray on two-dimensional, metastable rhodium oxide to enhance hydrogen evolution electrocatalysis.

Abstract Vacancy engineering is deemed as one of the powerful protocols to tune the catalytic activity of electrocatalysts. Herein, Se‐vacancy with charge polarization is created in the NiSe2 structure (NiSe2‐VSe) via a sequential phase conversion strategy. By a combined analysis of the Rietveld method, transient photovoltage spectra (TPV), in situ Raman and density functional theory (DFT) calculation, it is unequivocally discovered that the presence of charge‐polarized Se‐vacancy is beneficial for stabilizing the structure, decreasing the electron transfer kinetics, as well as optimizing the free adsorption energy of reaction intermediate during two‐electron oxygen reduction reaction (2e− ORR). Benefiting from these merits, the as‐prepared NiSe2‐VSe delivered the highest selectivity of 96% toward H2O2 in alkaline media, together with a selectivity higher than 90% over the wide potential range from 0.25 to 0.55 V, ranking it in the top level among the previously reported transition metal‐based electrocatalysts. Most notably, it also displayed admirable stability with only a slight selectivity decay after 5000 cycles of accelerated degradation test (ADT).

Abstract Electrochemical cell can overcome the inherent intermittence of the renewable energy sources, thus showing great potentials in applications ranging from electrical energy storage to future smart grid. However, the current electrochemical cells could not achieve the “total green” feature by fully utilizing the clean and abundant O2/H2O redox couples due to the enormous overpotentials for both oxygen reduction reaction (ORR) and oxygen release reaction (OER). Herein, we report a “total green” electrochemical composite film cell based on carbon dots (CDots), which can realize both ORR and OER in the acid environment. The in‐air voltage generation (0.95 V, with a maximum power of 5.3 μW) relies on the multiple‐electron‐transfer redox chemical reaction between the two active components inside the composite film, that is, ORR/OER of CDots and the redox reaction of polyaniline (PANI) on the electrode and the resulting proton concentration gradient. Interestingly, the cell can be self‐recovered at low load, recharged by adding H2O2, or electrocharged at high load. We anticipate that current study may open up new opportunities for designing and developing total‐green energy storage and conversion systems for diverse applications.

Abstract Positively charged Pt can work as the active center for hydrogen evolution reaction (HER) but the corresponding design of state‐of‐the‐art electrocatalysts at high current densities has never been realized. Here the application of positively charged Pt in an effective Fe‐PtNiPO nanoreactor for highly efficient and stable HER is demonstrated. Synchrotron radiation X‐ray absorption spectroscopy confirms the formation of internal positively charged Pt and the in situ experiments reveal the quick charge transfer in the nanoreactor. Ni‐based materials around Pt are used to tune the electronic structure and promote the water dissociation to form locally enriched H+, while a porous Fe shell can both prevent the loss of active material and allow the efficient material transport. All the beneficial compositions work together to form an effective nanoreactor for HER. As a result, the Fe‐PtNiPO nanoreactor shows a low overpotential of 19 mV to achieve 10 mA cm−2 and exhibits a high mass activity of 10.93 A mgPt−1 (at 100 mV). Most importantly, it only needs an ultra‐low overpotential of 193 mV to achieve a high current density of 1000 mA cm−2 with an excellent stability over 300 h, which represents one of the best electrocatalysts for alkaline HER and might be used for large‐scale industrial application in the future.

The alloying of noble metals with Cu is one of the most effective strategies for improving catalytic performance and reducing cost in electrocatalytic carbon dioxide reduction reactions (CO2RR). Previous works usually focused on the influence of morphology and composition on the catalytic activity, but lacked the study of the valence state ratio of metals and the electron transfer behavior on alloys. In this work, PdCu−2 alloy (Pd/Cu molar ratio is 1:2) was obtained by a simple one-step solvothermal method, which can effectively convert CO2 to CO with a maximum Faradaic efficiency (FE) of 85% at −0.9 V (vs. RHE). Then, the effect of the chemical state of Pd and Cu on the catalytic performance was investigated. The X-ray photoelectron spectroscopy (XPS) shows that the binding energy of Pd in PdCu alloy has a negative shift, which has affected the adsorption of key intermediates. When the proportion of oxidized state and zero-valent metal in the alloy is about 1:2, the PdCu alloy shows the best catalytic activity. In addition, the transient photovoltage (TPV) measurements further demonstrate that due to the introduction of Cu, the electron transfer rate of PdCu−2 becomes the slowest, which helps the accumulation of electrons on PdCu−2 and leads to the improvement of catalytic performance for electrocatalytic CO2RR. This work can provide more insights into the alloy catalysts of electrocatalytic CO2RR.

Carbon dots (CDs), as a unique zero-dimensional member of carbon materials, have attracted numerous attentions for their potential applications in optoelectronic, biological, and energy related fields. Recently, CDs as catalysts for energy conversion reactions under multi-physical conditions such as light and/or electricity have grown into a research frontier due to their advantages of high visible light utilization, fast migration of charge carriers, efficient surface redox reactions and good electrical conductivity. In this review, we summarize the fabrication methods of CDs and corresponding CD nanocomposites, including the strategies of surface modification and heteroatom doping. The properties of CDs that concerned to the photo- and electro-catalysis are highlighted and detailed corresponding applications are listed. More importantly, as new non-contact detection technologies, transient photo-induced voltage/current have been developed to detect and study the charge transfer kinetics, which can sensitively reflect the complex electron separation and transfer behavior in photo-/electro-catalysts. The development and application of the techniques are reviewed. Finally, we discuss and outline the major challenges and opportunities for future CD-based catalysts, and the needs and expectations for the development of novel characterization technologies.

Simultaneous electrochemical reduction of CO2 and H+/H2O is an attractive renewable route to produce syngas mixtures. Here, the authors introduce a ternary Co3O4-CDots-C3N4 electrocatalyst that couples hydrogen evolution and CO2 reduction catalysts and achieves cheap, stable and tunable production of syngas.

Summary: The efficient conversion of carbon dioxide (CO2) into useful chemicals has important practical significance for environmental protection. Until now, direct fixation of atmospheric CO2 needs first extraction from the atmosphere, an energy-intensive process. Silicon (or Si-H surface), Earth-abundant, low-cost and non-toxic, is a promising material for heterogeneous CO2 chemical fixation. Here we report one-step fixing of CO2 directly from the atmosphere to a paraformaldehyde-like polymer by Si-H surface at room temperature. With the assistance of HF, commercial silicon powder was used as a heterogeneous reducing agent, for converting gaseous CO2 to a polymer of fluorine substituted polyoxymethylene and hydroxyl substituted polyoxymethylene alternating copolymer (F-POM). Making use of the Si-H surface toward the fixation of atmospheric gaseous CO2 is a conceptually distinct and commercially interesting strategy for making useful chemicals and environmental protection. : Chemistry; Surface Chemistry; Global Carbon Cycle; Energy Sustainability Subject Areas: Chemistry, Surface Chemistry, Global Carbon Cycle, Energy Sustainability

The original HTML version of this Article omitted to list Yeshayahu Lifshitz as a corresponding author and incorrectly listed Shuit-Tong Lee as a corresponding author. Correspondingly, the original PDF version of this Article incorrectly stated that “Correspondence and requests for materials should be addressed to X.J. (email: xin.jiang@uni-siegen.de), or to Y.L. (email: yangl@suda.edu.cn), or to S.-T.L. (email: shayli@technion.ac.il), or to Z.K. (email: zhkang@suda.edu.cn)”, instead of the correct “Correspondence and requests for materials should be addressed to X.J. (email: xin.jiang@uni-siegen.de), or to Y. Liu (email: yangl@suda.edu.cn), or to Y. Lifshitz (email: shayli@technion.ac.il), or to Z.K. (email: zhkang@suda.edu.cn)”. This has now been corrected in the PDF and HTML versions of the Article.

Expansins are unique plant cell wall proteins that are involved in cell wall modifications underlying many plant developmental processes. In this work, we investigated the possible biological role of the root-specific α-expansin gene OsEXPA8 in rice growth and development by generating transgenic plants. Overexpression of OsEXPA8 in rice plants yielded pleiotropic phenotypes of improved root system architecture (longer primary roots, more lateral roots and root hairs), increased plant height, enhanced leaf number and enlarged leaf size. Further study indicated that the average cell length in both leaf and root vascular bundles was enhanced, and the cell growth in suspension cultures was increased, which revealed the cellular basis for OsEXPA8-mediated rice plant growth acceleration. Expansins are thought to be a key factor required for cell enlargement and wall loosening. Atomic force microscopy (AFM) technology revealed that average wall stiffness values for 35S::OsEXPA8 transgenic suspension-cultured cells decreased over six-fold compared to wild-type counterparts during different growth phases. Moreover, a prominent change in the wall polymer composition of suspension cells was observed, and Fourier-transform infrared (FTIR) spectra revealed a relative increase in the ratios of the polysaccharide/lignin content in cell wall compositions of OsEXPA8 overexpressors. These results support a role for expansins in cell expansion and plant growth.