Glycine-β-cyclodextrin-assisted cometabolism of phenanthrene and pyrene by Pseudomonas stutzeri DJP 1 from marine sediment

Cometabolic degradation is currently an effective and extensively way to remove high molecular weight polycyclic aromatic hydrocarbons(HMW-PAHs).Unfortunately,due to low bio-accessibility and high biotoxicity,the cometabolic degradation rate of HMW-PAHs is limited.Glycine-β-cyclodextrin(GCD)was obtained through amino modification ofβ-cyclodextrin(BCD)and added to cometabolic system of phenanthrene(PHE)and pyrene(PYR)to assist PYR biodegradation.Results show that the addition of GCD(100 mg/L)effectively improved the removal rate of PYR(20 mg/L)by 42.3%.GCD appeared to increase the bio-accessibility and reduce the biotoxicity of PHE and PYR,and then promoted the growth of Pseudomonas stutzeri DJP1 and stimulated the elevation of dehydrogenase(DHA)and catechol 12 dioxygenase(C12O)activities.The phthalate metabolic pathway was accelerated,which improved the cometabolic degradation.This study provided a new reference for the cometabolic degradation of HMW-PAHs.

Understanding carbon footprint:An evaluation criterion for achieving sustainable development

Excessive greenhouse gas emissions lead to global warming,which poses a critical challenge for human society.Worldwide consensus that carbon emissions must be reduced to achieve sustainable development has raised research interest on the topic of carbon footprint,an assessment standard for measuring greenhouse gas emissions.To shed light on this important topic,we introduce carbon footprint-related international standards and domestic policies,and conduct quantitative and qualitative analyses to provide a comprehensive overview of the current carbon footprint literature.Specifically,through a bibliometric analysis of 13203 carbon foot-print publications circulated over the past decade,we quantify the publication volume,influence,and collaboration networks of countries/regions,institutions,and journals.The results show that publications on carbon footprint have been increasing since 2013,and more so after 2017.Regarding domain influence,China and its academic institutions show a strong influence.In addition,a cluster analysis of the keywords of all publications shows seven categories,encompassing carbon footprint accounting methods and research priorities.Furthermore,a qualitative analysis of the research methods and subjects related to carbon footprint reveals the need to increase communication and collaboration among different disciplines and countries/regions to strengthen the construction of carbon footprint systems.Accordingly,this study identifies popular topics and development trends in the carbon footprint literature to provide research direction for promoting green and low-carbon transformation of the social economy to achieve sustainable development.

Applying machine-learning screening of single transition metal atoms anchored on N-dopedγ-graphyne for carbon monoxide electroreduction toward C_(1)products

Carbon monoxide electroreduction(COER)has been a key part of tandem electrolysis of carbon dioxide(CO_(2)),in which searching for high catalytic performance COER electrocatalysts remains a great challenge.Herein,by means of density functional theory(DFT)computations,we explored the potential of a series of transition metal atoms anchored on N-dopedγ-graphyne(TM@N-GY,TM from Ti to Au)as the COER electrocatalysts.We found that the final product selectivity of these single-atom catalysts depended on the position of the metal atom in the periodic table,with metals in the front and middle of each periodic period exhibiting high selectivity for CH_(4),while metals in the back producing CH_(3)OH.Machine learning(ML)found that metal atomic number was intrinsic to the difference in COER performance of these single-atom catalysts(SACs).The free energy changes showed that Mn@N-GY and Ni@N-GY exhibited outstanding COER catalytic performance for producing CH_(4)and CH_(3)OH,respectively.Our results provide theoretical and experimental guidance for designing efficient COER catalysts to generate C_(1)products.

Room-temperature liquid metal synthesis of nanoporous copper-indium heterostructures for efficient carbon dioxide reduction to syngas

Nanoporous metals show promising performances in electrochemical catalysis.In this paper,we report a self-supporting bimetallic porous heterogeneous indium/copper structure synthesized with a eutectic gallium-indium(EGaIn)material on a copper substrate.This nanoporous copper-indium heterostructure catalyst exhibits excellent performance in the reduction of carbon dioxide to syngas.The ratio of H_(2)/CO is tunable from 0.47 to 2.0 by changing working potentials.The catalyst is highly stable,showing 96%maintenance of the current density after a 70-h continuous test.Density functional theory calculations reveal that the indium/copper interface induces charge redistribution within the copper surface,leading to the formation of two distinct active sites,namely,Cu^(δ)and Cu0,and enabling a high-performance generation of CO and H_(2).This work provides a new strategy for obtaining self-supporting nanoporous metal electrode catalysts.

Outer delocalized electron aggregation of bromide bridged core–shell CuBr@C for hydrogen evolution reaction

Modulation of the surface electron distribution is a challenging problem that determines the adsorption ability of catalytic process.Here,we address this challenge by bridging the inner and outer layers of the core–shell structure through the bridge Br atom.Carbon shell wrapped copper bromide nanorods(CuBr@C)are constructed for the first time by chemical vapour deposition with hexabromobenzene(HBB).HBB pyrolysis provides both bridge Br atom and C shells.The C shell protects the stability of the internal halide structure,while the bridge Br atom triggers the rearrangement of the surface electrons and exhibits excellent electrocatalytic activity.Impressively,the hydrogen evolution reaction(HER)activity of CuBr@C is significantly better than that of commercial N-doped carbon nanotubes,surpassing commercial Pt/C at over 200 mA·cm^(−2).Density functional theory(DFT)calculations reveal that bridge Br atoms inspire aggregation of delocalized electrons on C-shell surfaces,leading to optimization of hydrogen adsorption energy.