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Volatile organic compounds (VOCs), particularly monoaromatic hydrocarbon compounds (MACHs), pose a potential risk to the atmospheric environment and human health. Therefore, the progressive development of efficient detection methodologies is a pertinent need, which is still a challenge at present. In this study, we present a rapid and sensitive method to detect trace amounts of MACHs using a bifunctional SERS composite substrate. We prepared an Au/SiO2 enhanced layer and a porous Cu(OH)2 adsorption layer via microfluidic-assisted gas-liquid interface self-assembly. The composite substrate effectively monitored changes in benzaldehyde using time-varying SERS spectra, and track-specifically identified various VOCs such as benzene, xylene, styrene, and nitrobenzene. In general, the substrate exhibited a rapid response time of 20 s to gaseous benzaldehyde, with a minimum detection concentration of less than 500 ppt. Further experimental assessments revealed an optimum Cu(OH)2 thickness of the surrounding adsorption layer of 150 nm, which can achieve an efficient SERS response to MACHs. Furthermore, the recoverable and reusable property of the composite substrate highlights its practicality. This study presents a straightforward and efficient approach for detecting trace gaseous VOCs using SERS, with significant implications in the designing of SERS substrates for detecting other VOCs. [ABSTRACT FROM AUTHOR]

Microencapsulating water-soluble ammonium persulfate (APS) cores as gel breakers were of considerable significance for improving the gel breaking efficiency of fracturing fluids in oil fields. The general approach, which was used for synthesizing microcapsules containing water-soluble APS cores, oil-soluble organic solvents as the continuous phase, was usually essential to retain the water-soluble properties of the core materials. From the environmentally friendly view, solventless methods for synthesizing these microcapsules will be more desirable and attractive. Presented in this report is a novel solventless method to fabricate the relevant microcapsules, water-soluble APS as the cores and polypyrrole doped with petroleum resin as the shells. The release pattern of the microcapsules is burst release, and its beginning release time could be precisely controlled by changing the type of doped resins and temperatures, which makes them promising candidates for oil exploration, monomer polymerization, fiber printing, batteries, and grease applications. [ABSTRACT FROM AUTHOR]

The performance of lithium‐metal batteries is severely hampered by uncontrollable dendrite growth and volume expansion on the metal anodes. Inspired by the "blockchain" concept in data mining, here we utilize a conductive polymer‐filled metal–organic framework (MOF) as the lithium host, in which polypyrrole (PPy) serves as the "chain" to interlink Li "blocks" stored in the MOF pores. While the N‐rich PPy guides fast Li+ infiltration/extrusion and serves as the nucleation sites for isotropic Li growth, the MOF pores compartmentalize bulk Li deposition for 3D matrix Li storage, leading to low‐barrier and dendrite‐free Li plating/stripping with superb Coulombic efficiency. The as‐fabricated lithium‐metal anodes operate over 700 cycles at 5 mA cm−2 in symmetric cells, and 800 cycles at 1 C in full cells with a per‐cycle capacity loss of only 0.017 %. This work might open a new chapter for Li‐metal anode construction by introducing the concept of "blockchain" management of Li plating/stripping. [ABSTRACT FROM AUTHOR]

The performance of lithium‐metal batteries is severely hampered by uncontrollable dendrite growth and volume expansion on the metal anodes. Inspired by the "blockchain" concept in data mining, here we utilize a conductive polymer‐filled metal–organic framework (MOF) as the lithium host, in which polypyrrole (PPy) serves as the "chain" to interlink Li "blocks" stored in the MOF pores. While the N‐rich PPy guides fast Li+ infiltration/extrusion and serves as the nucleation sites for isotropic Li growth, the MOF pores compartmentalize bulk Li deposition for 3D matrix Li storage, leading to low‐barrier and dendrite‐free Li plating/stripping with superb Coulombic efficiency. The as‐fabricated lithium‐metal anodes operate over 700 cycles at 5 mA cm−2 in symmetric cells, and 800 cycles at 1 C in full cells with a per‐cycle capacity loss of only 0.017 %. This work might open a new chapter for Li‐metal anode construction by introducing the concept of "blockchain" management of Li plating/stripping. [ABSTRACT FROM AUTHOR]

• High-potency bifunctional oxygen catalyst is enabled by rational catalyst design. • Low-cost natural guar gum is used to mass produce the catalyst. • ZAB performances of the catalyst competitive to Pt/C + RuO 2 were demonstrated. • Active sites are validated through post-reaction and operando characterizations. The development of bifunctional OER and ORR catalysts for reversible energy storage is challenging due to the requirement of both catalytic activity and stability in a broad potential range. Under the circumstance, rational catalyst design based on fundamental understanding of redox-active sites becomes particularly meaningful. Herein, we report a facile and low-cost approach utilizing natural guar gum to fabricate a high-performance bifunctional catalyst in mass scale incorporating both the CoP and Co-N-C moieties to afford simultaneous OER and ORR activities that are comparable to RuO 2 and Pt/C, respectively. Through exquisitely performed control studies, post-reaction analyses, and operando investigations, the OER and ORR active sites are validated as per initial catalyst design. Rechargeable Zinc-air batteries are further demonstrated manifesting energy efficiency, cycling stability, and high power density. This study marks the power of rational catalyst design by contriving redox-targeting moieties into hierarchical carbon scaffold to impart the desired functionalities. [ABSTRACT FROM AUTHOR]

Electrocatalytic conversion of carbon dioxide into high‐value multicarbon (C2+) chemical feedstocks offers a promising avenue to liberate the chemical industry from fossil‐resource dependence and eventually close the anthropogenic carbon cycle but is severely impeded by the lack of high‐performance catalysts. To break the linear scaling relationship of intermediate binding and minimize the kinetic barrier of CO2 reduction reactions, ternary Cu–Au/Ag nanoframes were fabricated to decouple the functions of CO generation and C−C coupling, whereby the former is promoted by the alloyed Ag/Au substrate and the latter is facilitated by the highly strained and positively charged Cu domains. Thus, C2H4 production in an H‐cell and a flow cell occurred with high Faradic efficiencies of 69±5 and 77±2 %, respectively, as well as good electrocatalytic stability and material durability. In situ IR and DFT calculations unveiled two competing pathways for C2H4 generation, of which direct CO dimerization is energetically favored. [ABSTRACT FROM AUTHOR]

Electrocatalytic conversion of carbon dioxide into high‐value multicarbon (C2+) chemical feedstocks offers a promising avenue to liberate the chemical industry from fossil‐resource dependence and eventually close the anthropogenic carbon cycle but is severely impeded by the lack of high‐performance catalysts. To break the linear scaling relationship of intermediate binding and minimize the kinetic barrier of CO2 reduction reactions, ternary Cu–Au/Ag nanoframes were fabricated to decouple the functions of CO generation and C−C coupling, whereby the former is promoted by the alloyed Ag/Au substrate and the latter is facilitated by the highly strained and positively charged Cu domains. Thus, C2H4 production in an H‐cell and a flow cell occurred with high Faradic efficiencies of 69±5 and 77±2 %, respectively, as well as good electrocatalytic stability and material durability. In situ IR and DFT calculations unveiled two competing pathways for C2H4 generation, of which direct CO dimerization is energetically favored. [ABSTRACT FROM AUTHOR]

• Weak intermolecular interaction results in low decomposition temperature. • Low temperature pyrolysis leads to less ripen of nickel particles. • Ni(OH) 2 islands formed spontaneously on the surface of less ripened Ni. • Ni/Ni(OH) 2 heterojunctions are responsible for the high performance of HER. • The HER kinetics of active Ni has a V-shaped pyrolysis temperature dependence. Pyrolysis of coordination compounds to synthesize efficient non-noble metal based electrocatalysts has been regarded as a useful tactic, but few efforts have been made in correlating the inter/intra-molecular interactions of the precursor complexes to the electrocatalytic properties of the final pyrolytic products. Herein, three coordination complexes with varied inter/intra-molecular interactions, including Ni(DMG), Ni(BDC), and Ni(BDC-NH 2) are employed as the precursors to fabricate metallic nickel particles for catalyzing HER in alkaline conditions. It is found the complex with a weaker inter/intra-molecular interaction requires a lower hydrogen-assisted decomposition temperature, which in turn produces less-ripened nickel particles but exhibiting higher electrochemical activity, evidenced by the V-shaped temperature dependence of HER kinetics. The best catalyst of Ni(DMG) 250 presents an overpotential of only 85 mV to reach 10 mA cm−2, close to that of commercial Pt/C, and is ascribed to a tandem reaction scheme on the Ni/Ni(OH) 2 heterojunctions formed on the highly active nickel surface. [ABSTRACT FROM AUTHOR]