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Electroreduction of carbon dioxide into useful fuels helps to reduce fossil-fuel consumption and carbon dioxide emissions, but activating carbon dioxide requires impractically high overpotentials; here a metal atomic layer combined with its native oxide that requires low overpotentials to reduce carbon dioxide is developed, adapted from an existing cobalt-based catalyst. Efficient electroreduction of CO 2 The production of useful fuels from carbon dioxide through electroreduction would be a clean way of replacing fossil fuels and reducing carbon dioxide emissions. Shan Gao et al . have turned cobalt, a metal generally considered not active for this reaction, into a very efficient electrocatalyst by synthesizing it in the form of four-atom-thick layers. This finding, and the observation that partial oxidation of the surface boosts activity further, points to a general strategy for turning otherwise unreactive metals into efficient electroreduction catalysts. Electroreduction of CO 2 into useful fuels, especially if driven by renewable energy, represents a potentially ‘clean’ strategy for replacing fossil feedstocks and dealing with increasing CO 2 emissions and their adverse effects on climate 1 , 2 , 3 , 4 . The critical bottleneck lies in activating CO 2 into the CO 2 •− radical anion or other intermediates that can be converted further, as the activation usually requires impractically high overpotentials. Recently, electrocatalysts based on oxide-derived metal nanostructures have been shown 5 , 6 , 7 , 8 to enable CO 2 reduction at low overpotentials. However, it remains unclear how the electrocatalytic activity of these metals is influenced by their native oxides, mainly because microstructural features such as interfaces and defects 9 influence CO 2 reduction activity yet are difficult to control. To evaluate the role of the two different catalytic sites, here we fabricate two kinds of four-atom-thick layers: pure cobalt metal, and co-existing domains of cobalt metal and cobalt oxide. Cobalt mainly produces formate (HCOO − ) during CO 2 electroreduction; we find that surface cobalt atoms of the atomically thin layers have higher intrinsic activity and selectivity towards formate production, at lower overpotentials, than do surface cobalt atoms on bulk samples. Partial oxidation of the atomic layers further increases their intrinsic activity, allowing us to realize stable current densities of about 10 milliamperes per square centimetre over 40 hours, with approximately 90 per cent formate selectivity at an overpotential of only 0.24 volts, which outperforms previously reported metal or metal oxide electrodes evaluated under comparable conditions 1 , 2 , 6 , 7 , 10 . The correct morphology and oxidation state can thus transform a material from one considered nearly non-catalytic for the CO 2 electroreduction reaction into an active catalyst. These findings point to new opportunities for manipulating and improving the CO 2 electroreduction properties of metal systems, especially once the influence of both the atomic-scale structure and the presence of oxide are mechanistically better understood.

The role of oxygen vacancies in carbon dioxide electroreduction remains somewhat unclear. Here we construct a model of oxygen vacancies confined in atomic layer, taking the synthetic oxygen-deficient cobalt oxide single-unit-cell layers as an example. Density functional theory calculations demonstrate the main defect is the oxygen(II) vacancy, while X-ray absorption fine structure spectroscopy reveals their distinct oxygen vacancy concentrations. Proton transfer is theoretically/experimentally demonstrated to be a rate-limiting step, while energy calculations unveil that the presence of oxygen(II) vacancies lower the rate-limiting activation barrier from 0.51 to 0.40 eV via stabilizing the formate anion radical intermediate, confirmed by the lowered onset potential from 0.81 to 0.78 V and decreased Tafel slope from 48 to 37 mV dec −1 . Hence, vacancy-rich cobalt oxide single-unit-cell layers exhibit current densities of 2.7 mA cm −2 with ca. 85% formate selectivity during 40-h tests. This work establishes a clear atomic-level correlation between oxygen vacancies and carbon dioxide electroreduction. The role of oxygen vacancies in carbon dioxide reduction remains somewhat unclear. Here, the authors fabricate vacancy-rich and vacancy-poor Co 3 O 4 single-unit-cell layers, and demonstrate by X-ray absorption and DFT that the material is a promising platform for mechanistic studies of carbon dioxide reduction.

Sluggish separation and migration kinetics of the photogenerated carriers account for the low-efficiency of CO 2 photoreduction into CH 4 . Design and construction two-dimensional (2D) in-plane heterostructures demonstrate to be an appealing approach to address above obstacles. Herein, we fabricate 2D in-plane heterostructured Ag 2 S-In 2 S 3 atomic layers via an ion-exchange strategy. Photoluminescence spectra, time-resolved photoluminescence spectra, and photoelectrochemical measurements firmly affirm the optimized carrier dynamics of the In 2 S 3 atomic layers after the introduction of in-plane heterostructure. In-situ Fourier transform infrared spectroscopy spectra and density functional theory (DFT) calculations disclose the in-plane heterostructure contributes to CO 2 activation and modulates the adsorption strength of CO* intermediates to facilitate the formation of CHO* intermediates, which are further protonated to CH 4 . In consequence, the in-plane heterostructure achieves the CH 4 evolution rate of 20 µmol·g −1 ·h −1 , about 16.7 times higher than that of the In 2 S 3 atomic layers. In short, this work proves construction of in-plane heterostructures as a promising method for obtaining high-efficiency CO 2 -to-CH 4 photoconversion properties.

Regulating the selectivity of CO 2 photoreduction is particularly challenging. Herein, we propose ideal models of atomic layers with/without element doping to investigate the effect of doping engineering to tune the selectivity of CO 2 photoreduction. Prototypical ZnCo 2 O 4 atomic layers with/without Ni-doping were first synthesized. Density functional theory calculations reveal that introducing Ni atoms creates several new energy levels and increases the density-of-states at the conduction band minimum. Synchrotron radiation photoemission spectroscopy demonstrates that the band structures are suitable for CO 2 photoreduction, while the surface photovoltage spectra demonstrate that Ni doping increases the carrier separation efficiency. In situ diffuse reflectance Fourier transform infrared spectra disclose that the CO 2 ·− radical is the main intermediate, while temperature-programed desorption curves reveal that the ZnCo 2 O 4 atomic layers with/without Ni doping favor the respective CO and CH 4 desorption. The Ni-doped ZnCo 2 O 4 atomic layers exhibit a 3.5-time higher CO selectivity than the ZnCo 2 O 4 atomic layers. This work establishes a clear correlation between elemental doping and selectivity regulation for CO 2 photoreduction, opening new possibilities for tailoring solar-driven photocatalytic behaviors.

Carbon dioxide electroreduction usually suffers from low catalytic activities and debatable reaction mechanisms at present. That may be primarily ascribed to the high energy barrier for carbon dioxide activation over the conventionally fabricated catalysts and the infeasibility of traditional characterization techniques for unveiling the evolution of active sites and reactive intermediates. Two-dimensional (2D) materials, which possess the active sites with high proportion, high activity and high uniformity, can act as ideal models to manipulate the active sites and understand structure-property relationship. In this review, we overview the boosted carbon dioxide activation by the intrinsic peculiar electronic states of 2D catalysts and the charge localization effect induced by chemical modification of two-dimensional catalysts. We also summarize the recognition of the structural evolutions for active sites in two-dimensional catalysts by means of in situ X-ray diffraction pattern and in situ X-ray absorption spectroscopy. Moreover, we emphasize the detection of the reactive intermediates on active sites in two-dimensional catalysts via in situ Raman spectroscopy and in situ Fourier transform infrared spectroscopy. Finally, we end this review with an outlook on the unresolved issues and future development of carbon dioxide electroreduction.

The conversion of carbon dioxide (CO2) into value‐added chemicals and renewable fuels is a promising approach to mitigate climate change and promote the development of sustainable energy systems. However, despite the broad range of products, including CO, formic acid and multi‐carbon hydrocarbons, the large‐scale implementation of CO2 conversion technologies is still hindered by low catalytic efficiency and high energy consumption. This review introduces recent advances in catalytic materials design, emphasizing the structure–property relationships that govern the performance of highly efficient catalysts across various CO2 conversion processes, including photocatalysis, electrocatalysis, CO2 hydrogenation, photothermal conversion, non‐thermal plasma techniques, and biological methodologies. By examining the synergies among catalyst architectures, key intermediates, catalytic mechanisms and reactor designs, this review explores the potential for tailored CO2 conversion processes with optimized reaction pathways to achieve specific catalytic products, and also provides a roadmap for the development of efficient, scalable CO2 conversion technologies to facilitate the transition to a circular carbon economy. This review systematically outlines recent advances in the catalytic strategies for converting CO₂ into valuable products, including photocatalysis, electrocatalysis, CO2 hydrogenation, photothermal catalysis, non‐thermal plasma, and biocatalytic processes. It highlights catalyst design, mechanistic insights, and pathway optimization for targeted products, providing a roadmap towards scalable technologies for a circular carbon economy.

The transcriptome of the preimplantation mouse embryo has been previously annotated by short-read sequencing, with limited coverage and accuracy. Here we utilize a low-cell number transcriptome based on the Smart-seq2 method to perform long-read sequencing. Our analysis describes additional novel transcripts and complexity of the preimplantation transcriptome, identifying 2280 potential novel transcripts from previously unannotated loci and 6289 novel splicing isoforms from previously annotated genes. Notably, these novel transcripts and isoforms with transcription start sites are enriched for an active promoter modification, H3K4me3. Moreover, we generate a more complete and precise transcriptome by combining long-read and short-read data during early embryogenesis. Based on this approach, we identify a previously undescribed isoform of Kdm4dl with a modified mRNA reading frame and a novel noncoding gene designated XLOC_004958 . Depletion of Kdm4dl or XLOC_004958 led to abnormal blastocyst development. Thus, our data provide a high-resolution and more precise transcriptome during preimplantation mouse embryogenesis. Until now, the transcriptome of preimplantation mouse embryos has only been analysed by short-read sequencing. Here, the authors perform long-read sequencing to provide a more detailed transcriptome of the preimplantation mouse embryo, identifying various novel transcripts, for example Kdm4dl.

Antibacterial peptide has been widely developed in cultivation industry as feed additives. However, its functions in reducing the detrimental impacts of soybean meal (SM) remain unknown. In this study, we prepared nano antibacterial peptide CMCS-gcIFN-20H (C-I20) with excellent sustained-release and anti-enzymolysis, and fed mandarin fish ( Siniperca chuatsi ) with a SM diet supplemented with different levels of C-I20 (320, 160, 80, 40, 0 mg/Kg) for 10 weeks. 160 mg/Kg C-I20 treatment significantly improved the final body weight, weight gain rate and crude protein content of mandarin fish and reduced feed conversion ratio. 160 mg/Kg C-I20-fed fish maintained appropriate goblet cells number and mucin thickness, as well as improved villus length, intestinal cross-sectional area. Based on these advantageous physiological changes, 160 mg/Kg C-I20 treatment effectively reduced multi-type tissue (liver, trunk kidney, head kidney and spleen) injury. The addition of C-I20 did not change the muscle composition and muscle amino acids composition. Interestingly, dietary 160 mg/Kg C-I20 supplementation prevented the reduction in myofiber diameter and change in muscle texture, and effectively increased polyunsaturated fatty acids (especially DHA + EPA) in muscle. In conclusion, dietary C-I20 in a reasonable concentration supplementation effectively alleviates the negative effects of SM by improving the intestinal mucosal barrier. The application of nanopeptide C-I20 is a prospectively novel strategy for promoting aquaculture development.

This study aims to systematically evaluate the effect of breathing exercises on the low back pain (LBP). The studies of relevant randomized controlled trials (RCTs) testing the effect of breathing exercises on LBP were selected after strict screening from the establishment of PubMed, EMBASE, Cochrane Library, Web of Science, CBM, and CNKI databases until September 2022. The studies included were then independently assessed for risk bias by two investigators. The PRISMA 2020 statement was followed in this study. 11 RCTs involving 383 patients were included in this analysis. Results showed that the effective rate of LBP patients after breathing exercises was significantly higher than those in the control group, and the VAS (Visual Analogue Score) and ODI (Oswestry Disability Index) scores of LBP patients were significantly lower than those in the control group [VAS: MD = −0.50, 95% CI (−0.88, −0.11), I2 = 76%, p = 0.0009; ODI: MD = −2.46, 95% CI (−3.41, −1.52), I2 = 20%, p = 0.28]. The results of subgroup showed that the duration of treatment had little effect on the effect of breathing exercises, and breathing exercises alone could also have a positive effect on LBP. However, there were methodological limitations in the included studies, future studies should ensure blinded outcome assessors and full reporting to reduce bias risks. Because this review is a study of breathing exercises as an intervention without any adverse events, all studies did not involve safety assessments. The results indicated that breathing exercises have a positive effect on alleviating LBP, but due to the lack of methodological rigor and some limitations of the included studies, more critical RCTs are still needed in the future to verify the precision of this conclusion. The protocol was registered in PROSPERO (No. CRD42022345561). •Breathing exercise is a safe therapy with no adverse events.•Breathing exercises can alleviate low back pain.•Breathing exercises can be used as a complementary therapy for patients with low back pain in the future.•A total of 11 studies with 458 patients were included in this review.

A Correction to this paper has been published: https://doi.org/10.1038/s41467-021-22148-6