Plasma-assisted synthesis of porous bismuth nanosheets for electrocatalytic CO_(2)-to-formate reduction

The electrochemical carbon dioxide reduction(eCO_(2)RR)to formate,driven by clean energy,is a promising approach for producing renewable chemicals and high-value fuels.Despite its potential,further development faces challenges due to limitations in electrocatalytic activity and durability,especially for nonnoble metal-based catalysts.Here,naturally abundant bismuth-based nanosheets that can effectively drive CO_(2)-to-formate electrocatalytic reduction are prepared using the plasma-activated Bi_(2)Se_(3) followed by a reduction process.Thus-obtained plasma-activated Bi nanosheets(P-BiNS)feature ultrathin structures and high surface areas.Such nanostructures ensure the P-BiNS with outstanding eCO_(2)RR catalytic performance,highlighted by the current density of over 80 mA cm^(-2) and a formate Faradic efficiency of>90%.Furthermore,P-BiNS catalysts demonstrate excellent durability and stability without deactivation following over 50h of operation.The selectivity for formate production is also studied by density functional theory(DFT)calculations,validating the importance and efficacy of the stabilization of intermediates(^(*)OCHO)on the P-BiNS surfaces.This study provides a facile plasma-assisted approach for developing high-performance and low-cost electrocatalysts.

Discharge plasma for prebiotic chemistry: Pathways to life’s building blocks

Discharge plasmas, recognized as unique platforms for investigating the origins of chemical life, have garnered extensive interest for their potential to simulate prebiotic conditions. This paper embarks on a comprehensive overview of recent advancements in the plasma-enabled synthesis of life’s building blocks, charting the complex environmental parameters believed to have surrounded life’s inception. This discussion elaborates on the fundamental mechanisms of discharge plasmas and their likely role in fostering conditions necessary for the origin of life on early Earth. We consider a variety of chemical reactions facilitated by plasma, specifically the synthesis of vital organic molecules - amino acids, nucleobases, sugars, and lipids. Further, we delve into the impact of plasmas on prebiotic chemical evolution. We expect this review to open new horizons for future investigations in plasma-related prebiotic chemistry that could offer valuable insights for unraveling the mysteries of life's origin.

A plausible pathway to prebiotic peptides via amino acid amides on the primordial Earth

The prebiotic synthesis of peptides prior to ribosome-catalyzed processes remains an enigma.The synthesis of abiotic peptides from amino acids(AAs)is primarily constrained by high activation energies and unfavorable thermodynamics,necessitating the identification of plausible prebiotic alternatives for synthesizing prebiotic peptides.Here we present a plausible pathway to the formation of prebiotic peptides,wherein oligopeptides,oligopeptide amides,and cyclic oligopeptides can be directly synthesized from amino acid amides(AA-NH2)under wet–dry cycle conditions without the need for any enhancers.The subsequent investigation revealed that AA-NH2 demonstrated more favorable thermodynamic reaction effects than AAs in peptide formation.In contrast to the polymerization of AAs,the process of peptide formation through the polymerization of AA-NH2 was significantly simplified.Additionally,AA-NH2 was discovered to function as a“bridge”for the formation of peptides from AAs,thereby facilitating their participation in the synthesis of intricate peptide structures.On the basis of these findings,a plausible mechanism for the prebiotic origin network of peptides under primordial Earth conditions has been proposed.Overall,this research presents a plausible pathway for the generation of prebiotic peptides and peptide libraries within prebiotic environments.

Plasma-electrified up-carbonization for low-carbon clean energy

Low-value,renewable,carbon-rich resources,with different biomass feedstocks and their derivatives as typical examples,represent virtually inexhaustive carbon sources and carbon-related energy on Earth.Upon conversion to higher-value forms(referred to as“up-carbonization”here),these abundant feedstocks provide viable opportunities for energy-rich fuels and sustainable platform chemicals production.However,many of the current methods for such up-carbonization still lack sufficient energy,cost,and material efficiency,which affect their economics and carbon-emissions footprint.With external electricity precisely delivered,discharge plasmas enable many stubborn reactions to occur under mild conditions,by creating locally intensified and highly reactive environments.This technology emerges as a novel,versatile technology platform for integrated or stand-alone conversion of carbon-rich resources.The plasma-based processes are compatible for integration with increasingly abundant and cost-effective renewable electricity,making the whole conversion carbon-neutral and further paving the plasma-electrified upcarbonization to be performance-,environment-,and economics-viable.Despite the chief interest in this emerging area,no review article brings together the state-of-the-art results from diverse disciplines and underlies basic mechanisms and chemistry underpinned.As such,this review aims to fill this gap and provide basic guidelines for future research and transformation,by providing an overview of the application of plasma techniques for carbon-rich resource conversion,with particular focus on the perspective of discharge plasmas,the fundamentals of why plasmas are particularly suited for upcarbonization,and featured examples of plasma-enabled resource valorization.With parallels drawn and specificity highlighted,we also discuss the technique shortcomings,current challenges,and research needs for future work.

Sustainable Ammonia Synthesis from Nitrogen and Water by One-Step Plasma Catalysis

Sustainable ammonia synthesis at ambient conditions that relies on renewable sources of energy and feedstocks is globally sought to replace the Haber-Bosch process.Here,using nitrogen and water as raw materials,a nonthermal plasma catalysis approach is demonstrated as an effective powerto-chemicals conversion strategy for ammonia production.By sustaining a highly reactive environment,successful plasma-catalytic production of NH_(3) was achieved from the dissociation of N_(2) and H_(2)O under mild conditions.Plasma-induced vibrational excitation is found to decrease the N_(2) and H_(2)O dissociation barriers,with the presence of matched catalysts in the nonthermal plasma discharge reactor contributing significantly to molecular dissociation on the catalyst surface.Density functional theory calculations for the activation energy barrier for the dissociation suggest that ruthenium catalysts supported on magnesium oxide exhibit superior performance over other catalysts in NH_(3) production by lowering the activation energy for the dissociative adsorption of N_(2) down to 1.07 eV.The highest production rate,2.67 mmol gcat.^(-1) h^(-1),was obtained using ruthenium catalyst supported on magnesium oxide.This work highlights the potential of nonthermal plasma catalysis for the activation of renewable sources to serve as a new platform for sustainable ammonia production.

Corrigendum to“Reactive oxygen species in plasma against E.coli cells survival rate”

Recently, we found some errors in Fig. 3 of the article Chin. Phys. B 24 085201 (2015). Upon a thorough examination of the raw data materials, we confirm that the image error did not impact any of the findings and conclusions of the paper. Based on this, we have made corrections to the original article.

Design and characteristics investigation of a miniature low-temperature plasma spark discharge device

Atmospheric pressure low-temperature plasma is a promising tool in biomedicine applications including blood coagulation,bacterial inactivation,sterilization,and cancer treatment,due to its high chemical activity and limited thermal damage.It is of great importance to develop portable plasma sources that are safe to human touch and suitable for outdoor and household operation.In this work,a portable and rechargeable low-temperature plasma spark discharge device(130 mm×80 mm×35 mm,300 g)was designed.The discharge frequency and plume length were optimized by the selection of resistance,capacitance,electrode gap,and ground electrode aperture.Results show that the spark plasma plume is generated with a length of 12 mm and a frequency of 10 Hz at a capacitance of 0.33μF.resistance of 1 MΩ,electrode gap of 2 mm,and ground electrode aperture of 1.5 mm.Biological tests indicate that the plasma produced by this device contains abundant reactive species,which can be applied in plasma biomedicine,including daily sterilization and wound healing.

Bacterial nanocellulose assembly into super-strong and humidity-responsive macrofibers

Cellulose macrofibers (MFs) are gaining increasing interest as natural and biodegradable alternatives to fossil-derived polymers for both structural and functional applications. However, simultaneously achieving their exceptional mechanical performance and desired functionality is challenging and requires complex processing. Here, we reported a one-step approach using a tension-assisted twisting (TAT) technique for MF fabrication from bacterial cellulose (BC). The TAT stretches and aligns BC nanofibers pre-arranged in hydrogel tubes to form MFs with compactly assembled structures and enhanced hydrogen bonding among neighboring nanofibers. The as-prepared BC MFs exhibited a very high tensile strength of 1 057 MPa and exceptional lifting capacity (over 340 000 when normalized by their own weight). Moreover, due to the volume expansion of BC nanofibers upon water exposure, BC MFs quickly harvested energy from environmental moisture to untwist the bundled networks, thus generating a torsional spinning with a peak rotation speed of 884 r/(min·m). The demonstrated rapid and intense actuation response makes the MFs ideal candidates for diverse humidity-response-based applications beyond advanced actuators, remote rain indicators, intelligent switches, and smart curtains.

Recent applications in dielectric barrier discharge and radio frequency plasmas‐engineered transition metal electrocatalysts for water splitting

Hydrogen generated by water electrolysis is considered as one of the most promising protocols to partly replace the roles of traditional fossil fuels.However,high‐performance electrocatalyst satisfied with the industrial requirement still faces significant challenges.Low‐temperature plasma contains numerous high‐energy ions,electrons and other reactive species,which can provide a highly reactive environment for tuning the physio‐chemical structures of catalysts through plasma milling,etching,doping and/or deposi-tion.It is well‐known that high‐temperature micro‐filaments contained in plasmas can cause some special modifications of the catalyst surface,thus effectively adjusting the physio‐chemical structure of latterly engineered compounds.Therefore,low‐temperature plasma technologies,especially the dielectric barrier discharge(DBD)and radio frequency(RF)plasmas,can be considered as a green and sustainable strategy for engineering high‐performance electrocatalysts for water splitting(hydrogen evolution reaction[HER];oxygen evolution reaction[OER]).Herein,recent progress of DBD and RF plasmas for fabricating and modifying transition metal‐based electrocatalysts(e.g.sulphide,phos-phide,selenide,oxide,hydroxide)for hydrogen evolution reaction or OER is compre-hensively reviewed,and the role of plasma is also discussed.

Power-to-chemicals:sustainable liquefaction of food waste with plasma-electrolysis

The increasing amount of food waste from various industrial,agricultural,and household sources is an environmental burden if managed inappropriately.Numerous waste management approaches have been developed for the disposal of food waste,but still suffer from either high cost,production of toxic by-products,or secondary environmental pollutions.Herein,we report a new and sustainable plasma electrolysis biorefinery route for the rapid and efficient liquefaction of food waste.During the plasma electrolysis process,only the solvent is added to liquefy the waste,and anions in the waste can contribute to catalyzing the biowaste conversion.While liquefying the waste,the highly reactive species produced in the plasma electrolysis process can efficiently reduce the content of O,N,and Cl in the liquefied products and oxidize most of the metals into solid residues.Especially,the removal rate of Na and K elements was greater than 81%,which is significantly higher than using the traditional oil bath liquefaction,resulting in a relatively high-quality biocrude oil with a high heating value of 25.86 MJ·kg^(-1).Overall,this proposed strategy may provide a new sustainable and eco-friendly avenue for the power-to-chemicals valorization of food waste under benign conditions.

Continuous flow removal of acid fuchsine by dielectric barrier discharge plasma water bed enhanced by activated carbon adsorption

Continuous processes which allow for large amount of wastewater to be treated to meet drainage standards while reducing treatment time and energy consumption are urgently needed. In this study, a dielectric barrier discharge plasma water bed system was designed and then coupled with granular activated carbon (GAC) adsorption to rapidly remove acid fuchsine (AF) with high efficiency. Effects of feeding gases, treatment time and initial concentration of AF on removal efficiency were investigated. Results showed that compared to the N2 and air plasmas treatments, O2 plasma processing was most effective for AF degradation due to the strong oxidation ability of generated activated species, especially the OH radicals. The addition of GAC significantly enhanced the removal efficiency of AF in aqueous solution and shorten the required time by 50%. The effect was attributed to the ability of porous carbon to trap and concentrate the dye, increasing the time dye molecules were exposed to the plasma discharge zone, and to enhance the production of OH radicals on/in GAC to boost the degradation of dyes by plasma as well as in situ regenerate the exhausted GAC. The study offers a new opportunity for continuous effective remediation of wastewater contaminated with organic dyes using plasma technologies.

Non-thermal plasma enhances performances of biochar in wastewater treatment and energy storage applications

Surface functionalization or modification to introduce more oxygen-containing functional groups to biochar is an effective strategy for tuning the physicochemical properties and promoting follow-up applications.In this study,non-thermal plasma was applied for biochar surface carving before being used in contaminant removal and energy storage applications.The results showed that even a low dose of plasma exposure could introduce a high number density of oxygen-functional groups and enhance the hydrophilicity and metal affinity of the pristine biochar.The plasma-treated biochar enabled a faster metal-adsorption rate and a 40%higher maximum adsorption capacity of heavy metal ion Pb^(2+).Moreover,to add more functionality to biochar surface,biochar with and without plasma pre-treatment was activated by KOH at a temperature of 800℃.Using the same amount of KOH,the plasma treatment resulted in an activated carbon product with the larger BET surface area and pore volume.The performance of the treated activated carbon as a supercapacitor electrode was also substantially improved by>30%.This study may provide guidelines for enhancing the surface functionality and application performances of biochar using non-thermal-based techniques.