The three-pillar conception of (social, economic and environmental) sustainability, commonly represented by three intersecting circles with overall sustainability at the centre, has become ...ubiquitous. With a view of identifying the genesis and theoretical foundations of this conception, this paper reviews and discusses relevant historical sustainability literature. From this we find that there is no single point of origin of this three-pillar conception, but rather a gradual emergence from various critiques in the early academic literature of the economic status quo from both social and ecological perspectives on the one hand, and the quest to reconcile economic growth as a solution to social and ecological problems on the part of the United Nations on the other. The popular three circles diagram appears to have been first presented by Barbier (Environ Conserv 14:101, doi: 10.1017/s0376892900011449,
1987
), albeit purposed towards developing nations with foci which differ from modern interpretations. The conceptualisation of three pillars seems to predate this, however. Nowhere have we found a theoretically rigorous description of the three pillars. This is thought to be in part due to the nature of the sustainability discourse arising from broadly different schools of thought historically. The absence of such a theoretically solid conception frustrates approaches towards a theoretically rigorous operationalisation of ‘sustainability’.
A general and simple route to fabricate graphdiyne nanowalls on arbitrary substrates is developed by using a copper envelope catalysis strategy. The GDY/BiVO4 system is but one example of combing the ...unique properites of GDY with those target substrates where GDY improves the photoelectrochemical performance dramatically.
Colloidal quantum dots (QDs) consisting of precious‐metal‐free elements show attractive potentials towards solar‐driven CO2 reduction. However, the inhibition of hydrogen (H2) production in aqueous ...solution remains a challenge. Here, we describe the first example of a carbon–carbon (C−C) coupling reaction to block the competing H2 evolution in photocatalytic CO2 reduction in water. In a specific system taking ZnSe QDs as photocatalysts, the introduction of furfural can significantly suppress H2 evolution leading to CO evolution with a rate of ≈5.3 mmol g−1 h−1 and a turnover number (TON) of >7500 under 24 h visible light. Meanwhile, furfural is upgraded to the self‐coupling product with a yield of 99.8 % based on the consumption of furfural. Mechanistic insights show that the reductive furfural coupling reaction occurs on surface Zn‐sites to consume electrons and protons originally used for H2 production, while the CO formation pathway at surface anion vacancies from CO2 remains.
Reductive carbon–carbon coupling was used to block H2 evolution in CO2 photoreduction in water. Furfural, one of the biomass platform molecules, adsorbs on Zn‐sites consuming electrons and protons originally used for H2 production, but the CO formation pathway at surface anion vacancies remains. Therefore, CO was evolved with a CO/H2 ratio of 265 : 1 in the gas phase and furfural was upgraded to value‐added hydrofuroin.
2+2 Photocycloaddition, for example, the dimerization of chalcones and cinnamic acid derivatives, is a unique strategy to construct cyclobutanes, which are building blocks for a variety of ...biologically active molecules and natural products. However, most attempts at the above 2+2 addition have focused on solid‐state, molten‐state, or host–guest systems under ultraviolet‐light irradiation in order to overcome the competition of facile geometric isomerization of nonrigid olefins. We report a general and simple method to realize the intermolecular 2+2 dimerization reaction of these acyclic olefins to construct cyclobutanes in a highly regio‐ and diastereoselective manner in solution under visible light, which provides an efficient solution to a long‐standing problem.
Circle of light: Visible‐light‐induced energy transfer can be used to construct cyclobutanes from nonrigid olefins in a highly regio‐ and diastereoselective manner through 2+2 photocycloaddition. Chalcones and cinnamic acid derivatives were reacted to give cyclobutanes with high yields at room temperature.
Graphdiyne (GDY), a novel large π-conjugated carbon material, for the first time, is introduced as the hole transfer layer into a photoelectrochemical water splitting cell (PEC). Raman and ...ultraviolet photoelectron spectroscopic studies indicate the existence of relatively strong π–π interactions between GDY and 4-mercaptopyridine surface-functionalized CdSe quantum dots, beneficial to the hole transportation and enhancement of the photocurrent performance. Upon exposure to a Xe lamp, the integrated photocathode produces a current density of nearly −70 μA cm–2 at a potential of 0 V vs NHE in neutral aqueous solution. Simultaneously, the photocathode evolves H2 with 90 ± 5% faradic efficiency over three times and exhibits good stability within 12 h. All of the results indicate that GDY is a promising hole transfer material to fabricate a PEC device for water splitting by solar energy.
Inspired by the cubic Mn4CaO5 cluster of natural oxygen‐evolving complex in Photosystem II, tetrametallic molecular water oxidation catalysts, especially M4O4 cubane‐like clusters (M=transition ...metals), have aroused great interest in developing highly active and robust catalysts for water oxidation. Among these M4O4 clusters, however, copper‐based molecular catalysts are poorly understood. Now, bio‐inspired Cu4O4 cubanes are presented as effective molecular catalysts for electrocatalytic water oxidation in aqueous solution (pH 12). The exceptional catalytic activity is manifested with a turnover frequency (TOF) of 267 s−1 for (LGly‐Cu)4 at 1.70 V and 105 s−1 for (LGlu‐Cu)4 at 1.56 V. Electrochemical and spectroscopic study revealed a successive two‐electron transfer process in the Cu4O4 cubanes to form high‐valent CuIII and CuIIIO. intermediates during the catalysis.
Cu4O4 cubanes show exceptional activity for electrocatalytic water oxidation in aqueous solution, with a turnover frequency of 267 s−1 for (LGly‐Cu)4 at 1.70 V and 105 s−1 for (LGlu‐Cu)4 at 1.56 V, respectively. The unique cuboidal structure and high catalytic performance is reminiscent of the natural Mn4CaO5 clusters in PS II.
Currently, knowledge about the impact of high‐grain (HG) feeding on rumen microbiota and metabolome is limited. In this study, a combination of the 454 pyrosequencing strategy and the mass ...spectrometry‐based metabolomics technique was applied to investigate the effects of increased dietary grain (0%, 25% and 50% maize grain) on changes in whole ruminal microbiota and their metabolites using goat as a ruminant model. We observed a significant influence of HG feeding in shaping the ruminal bacterial community structure, diversity and composition, with an overall dominance of bacteria of the phylum Firmicutes along with a low abundance of Bacteriodetes in the HG group. High‐grain feeding increased the number of ciliate and methanogens, and decreased the density of anaerobic fungi and the richness of the archaeal community. The metabolomics analysis revealed that HG feeding increased the levels of several toxic, inflammatory and unnatural compounds, including endotoxin, tryptamine, tyramine, histamine and phenylacetate. Correlation analysis on the combined datasets revealed some potential relationships between ruminal metabolites and certain microbial species. Information about these relationships may prove useful in either direct (therapeutic) or indirect (dietary) interventions for ruminal disorders due to microbial compositional shifts, such as ruminal acidosis.
The catalytic nature of semiconducting quantum dots (QDs) for photocatalytic hydrogen (H2) evolution can be thoroughly aroused, not because of coupling with external cocatalysts, but through ...partially covering controlled amount of ZnS shell on the surface. Specifically, CdSe QDs, with an optimal coverage of ZnS (≈46%), can produce H2 gas with a constant rate of ≈306.3 ± 21.1 µmol mg−1 h−1 during 40 h, thereby giving a turnover number of ≈(4.4 ± 0.3) × 105, which is ≈110‐fold to that of unmodified CdSe QDs under identical conditions. The performance of H2 evolution is comparable to or even better than the commonly used external cocatalysts, e.g., metal complexes, noble metals assisted photosystems. Mechanistic insights indicate that the dramatically enhanced activity and stability of bare QDs for photocatalytic H2 production are derived from (i) inhibiting exciton annihilation at trap states, (ii) preventing the photo‐oxidation of core frameworks, and (iii) retaining tunneling efficiencies of photogenerated electrons and holes to reactive sites with partial ZnS coverage.
The self‐catalytic nature of semiconducting quantum dots (QDs) for photocatalytic H2
evolution can be thoroughly aroused by a simple surface engineering method, which not only eliminates the reliance on external cocatalysts in designing artificial photocatalysts, but also provides privileges in making QD‐based devices practically viable.
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•Li-B isotopes analysis is a useful method to determine the source of ore-forming elements in Li-rich salt lakes.•The occurrence of secondary mineral precipitation leading to a ...decline in the values of δ7Li and δ11B.•Magnesite deposited at Lakko Co (sulfate type), influences the B isotope value, while having no effect on Li isotope value.•Hydrochemistryand Li-B isotopes reveal rock weatheringand geothermal fluids as potential B and Li sources in the Lakko Co.
A comprehensive comprehension of the origin and ore-forming process of lithium brine deposits is imperative prior to engaging in lithium resource exploration, development and utilization. Nevertheless, the provenance of lithium in salt lakes has always been controversial. The lithium and boron (Li and B) isotopes, which serve as discerning geochemical tracers, can facilitate the monitoring of geological processes and sources. In this study, we investigated the hydrochemistry, Li and B isotope characteristics of surface brine and recharge river samples collected from the Lakko Co on the Qinghai-Tibet Plateau in China. The dissolved Li concentrations range from 0.11 to 590.8 mg/L, δ7Li and δ11B values exhibit a range of 0.75∼8.11 ‰ and -18.29∼-4.01 ‰, respectively. Concentrations of elements such as Rb, and Cu are relatively high and exhibit a strong correlation with Li. Ions composition and content ratios indicate the deep origin of Li and B. The analysis of δ7Li and δ11B suggests that, apart from hot spring, weathering of surrounding rocks also contributes to the presence of Li and B. Besides, variations in δ11B values within the lake brine analysis may be attributed to the deposition of water Magnesite at the lake bottom. The findings suggest that the recharge water system and hot springs serve as the primary source of Li and B in Lakko Co. Additionally, the interaction between water and rock in the deep crust as well as chemical weathering in the shallow environment, significantly contribute to formation of Li-rich fluids. The transportation process is characterized by the precipitation of secondary mineral, resulting in an increase of δ7Li and δ11B. Furthermore, the presence of water Magnesite in the lake brine leads to fluctuations in δ11B. This investigation of the lake contributes to a more comprehensive understanding of the origins and mechanisms involved in the transportation and storage of lithium in lithium-rich salt lakes.
Hydrothermally synthesized single-crystalline hematite (α-Fe2O3) nanorods were investigated as an anode material for Li-ion batteries. Electrodes prepared with this material exhibited initial ...reversible capacities of 908 mAh g–1 at 0.2 C rate and 837 mAh g–1 at 0.5 C rate, and these capacities were completely retained after numerous cycles. The α-Fe2O3 nanorods average ∼40 nm in diameter and ∼400 nm in length providing a short path for lithium-ion diffusion and effective accommodation of the strain generated from volume expansion during the lithiation/delithiation process.
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