Selective sulfur conversion with surface engineering of electrocatalysts in a lithium-sulfur battery

The sluggish kinetics of multiphase sulfur conversion with homogeneous and heterogeneous electrochemical processes,causing the“shuttle effect”of soluble polysulfide species(PSs),is the challenges in terms of lithium-sulfur batteries(LSBs).In this paper,a Mn_(3)O_(4-x) catalyst,which has much higher activity for heterogeneous reactions than for homogeneous reactions(namely,preferentialactivity catalysts),is designed by surface engineering with rational oxygen vacancies.Due to the rational design of the electronic structure,the Mn_(3)O_(4-x) catalyst prefers to accelerate the conversion of Li2S4 into Li_(2)S_(2)/Li_(2)S and optimize Li_(2)S deposition,reducing the accumulation of PSs and thus suppressing the“shuttle effect.”Both density functional theory calculations and in situ X-ray diffraction measurements are used to probe the catalytic mechanism and identify the reaction intermediates of MnS and Li_(y)Mn_(z)O_(4-x) for fundamental understanding.The cell with Mn_(3)O_(4-x) delivers an ultralow attenuation rate of 0.028% per cycle over 2000 cycles at 2.5 C.Even with sulfur loadings of 4.93 and 7.10mg cm^(-2) in a lean electrolyte(8.4μL mg s^(-1)),the cell still shows an initial areal capacity of 7.3mAh cm^(-2).This study may provide a new way to develop preferential-activity heterogeneous-reaction catalysts to suppress the“shuttle effect”of the soluble PSs generated during the redox process of LSBs.

Electrochemical Carbon Dioxide Reduction to Ethylene:From Mechanistic Understanding to Catalyst Surface Engineering

Electrochemical carbon dioxide reduction reaction(CO_(2)RR)provides a promising way to convert CO_(2)to chemicals.The multicarbon(C_(2+))products,especially ethylene,are of great interest due to their versatile industrial applications.However,selectively reducing CO_(2)to ethylene is still challenging as the additional energy required for the C–C coupling step results in large overpotential and many competing products.Nonetheless,mechanistic understanding of the key steps and preferred reaction pathways/conditions,as well as rational design of novel catalysts for ethylene production have been regarded as promising approaches to achieving the highly efficient and selective CO_(2)RR.In this review,we first illustrate the key steps for CO_(2)RR to ethylene(e.g.,CO_(2)adsorption/activation,formation of~*CO intermediate,C–C coupling step),offering mechanistic understanding of CO_(2)RR conversion to ethylene.Then the alternative reaction pathways and conditions for the formation of ethylene and competitive products(C_1 and other C_(2+)products)are investigated,guiding the further design and development of preferred conditions for ethylene generation.Engineering strategies of Cu-based catalysts for CO_(2)RR-ethylene are further summarized,and the correlations of reaction mechanism/pathways,engineering strategies and selectivity are elaborated.Finally,major challenges and perspectives in the research area of CO_(2)RR are proposed for future development and practical applications.

Attapulgite nanorods assisted surface engineering for separator to achieve high-performance lithium–sulfur batteries

Lithium-sulfur(Li-S)batteries have been recognized as one of the most promising candidates for nextgeneration portable electronic devices,owing to their extremely high energy density and low cost.However,the dissolution of lithium polysulfides(LiPSs)and consequent"shuttle effect"seriously hinder the practical deployment of Li-S batteries.Herein,multi-metal oxide nanorods named attapulgite are proposed as multifunctional ionic sieve to immobilize LiPSs and further promote the regulation of LiPSs.Attapulgite,consisting of Al,Mg,Fe,Si and O ions,possesses more polar sites to immobilize LiPSs in comparison with single metal oxides.In addition,the catalytic nature(Fe ions)of attapulgite avails the LiPSs conversion reaction,which is further confirmed by the linear sweep voltammetry and electrochemical impedance spectroscopy.Benefited from the synergistic effect of multi-metal oxide and conductive carbon,the Li-S battery with the modified separator delivers remarkable discharge capacities of 1059.4 mAh g-1 and 792.5 mAh g-1 for the first and 200th cycle at 0.5 C,respectively.The work presents an effective way to improve the electrochemical performance of Li-S batteries by employing attapulgite nanorods assisted separator surface engineering.

Atomic-level insights into surface engineering of semiconductors for photocatalytic CO_(2) reduction

Photocatalytic conversion of CO_(2)into solar fuels provides a bright route for the green and sustainable development of human society.However,the realization of efficient photocatalytic CO_(2)reduction reaction(CO_(2)RR)is still challenging owing to the sluggish kinetics or unfavorable thermodynamics for basic chemical processes of CO_(2)RR,such as adsorption,activation,conversion and product desorption.To overcome these shortcomings,recent works have demonstrated that surface engineering of semiconductors,such as introducing surface vacancy,surface doping,and cocatalyst loading,serves as effective or promising strategies for improved photocatalytic CO_(2)RR with high activity and selectivity.The essential reason lies in the activation and reaction pathways can be optimized and regulated through the reconstruction of surface atomic and electronic structures.Herein,in this review,we focus on recent research advances about rational design of semiconductor surface for photocatalytic CO_(2)RR.The surface engineering strategies for improved CO_(2)adsorption,activation,and product selectivity will be reviewed.In addition,theoretical calculations along with in situ characterization techniques will be in the spotlight to clarify the kinetics and thermodynamics of the reaction process.The aim of this review is to provide deep understanding and rational guidance on the design of semiconductors for photocatalytic CO_(2)RR.

Improving the activity and stability of Ni-based electrodes for solid oxide cells through surface engineering:Recent progress and future perspectives

Solid oxide cells(SOCs)have attracted great attention in the past decades because of their high conversion efficiency,low environmental pollution and diversified fuel options.Nickel-based catalysts are the most widely used fuel electrode materials for SOCs due to the low price and high activity.However,when hydrocarbon fuels are employed,nickel-based electrodes face serious carbon deposition challenges,leading to a rapid decline of cell performance.Great efforts have been devoted to understanding the occurrence of the coking reaction,and to improving the stability of the electrodes in hydrocarbon fuels.In this review,we summarize recent research progress of utilizing surface modification to improve the stability and activity of Ni-based electrodes for SOCs by preventing carbon coking.The review starts with a briefly introduction about the reaction mechanism of carbon deposition,followed by listing several surface modification technologies and their working principles.Then we introduce representative works using surface modification strategies to prevent carbon coking on Ni-based electrodes.Finally,we highlight future direction of improving electrode catalytic activity and anti-coking performance through surface engineering.

Surface engineering of 1D nanocatalysts for value-added selective electrooxidation of organic chemicals

Electrolytic water splitting by renewable energy is a technology with great potential for producing hydrogen(H_(2))without carbon emission,but this technical route is hindered by its huge energy(electricity)cost,which is mainly wasted by the anode oxygen evolution reaction(OER)while the value of the anode product(oxygen)is very limited.Replacing the high-energy-cost OER with a selective organic compound electrooxidation carried out at a relatively lower potential can reduce the electricity cost while producing value-added chemicals.Currently,H_(2) generation coupled with synthesis of value-added organic compounds faces the challenge of low selectivity and slow generation rate of the anodic products.One-dimensional(1D)nanocatalysts with a unique morphology,well-defined active sites,and good electron conductivity have shown excellent performance in many electrocatalytic reactions.The rational design and regulation of 1D nanocatalysts through surface engineering can optimize the adsorption energy of intermediate molecules and improve the selectivity of organic electrooxidation reactions.Herein,we summarized the recent research progress of 1D nanocatalysts applied in different organic electrooxidation reactions and introduced several different fabrication strategies for surface engineering of 1D nanocatalysts.Then,we focused on the relationship between surface engineering and the selectivity of organic electrooxidation reaction products.Finally,future challenges and development prospects of 1D nanocatalysts in the coupled system consisting of organic electrooxidation and hydrogen evolution reactions are briefly outlined.

Surface engineering with ionic polymers on membranes for boron removal

Removal of boric acid from seawater and wastewater using reverse osmosis membrane technologies is imperative and yet remains inadequately addressed by current commercial membranes.Existing research efforts performed post-modification of reverse osmosis membranes to enhance boron rejection,which is usually accompanied by substantial sacrifice in water permeability.This study delves into the surface engineering of low-pressure reverse osmosis membranes,aiming to elevate boron removal efficiency while maintaining optimal salt rejection and water permeability.Membranes were modified by the self-polymerization and co-deposition of dopamine and polystyrene sulfonate at varying ratios and concentrations.The surfaces became smoother and more hydrophilic after modification.The optimum membrane exhibited a water permeability of 9.2±0.1 L·m^(-2)·h^(-1)·bar^(-1),NaCl rejection of 95.8%±0.3%,and boron rejection of 49.7%±0.1%and 99.6%±0.3%at neutral and alkaline pH,respectively.The water permeability is reduced by less than 15%,while the boron rejection is 3.7 times higher compared to the blank membrane.This research provides a promising avenue for enhancing boron removal in reverse osmosis membranes and addressing water quality concerns in the desalination process.

Spontaneous hierarchical surface engineering of minerals through coupled dissolution-precipitation chemistry

Peculiar hierarchical microstructures in creatures inspire modern material design with distinct functionalities.Creatures can effortlessly construct sophisticated yet long-range ordered microstructure across bio-membrane through ion secretion and precipitation.However,microstructure biomimicry in current technology generally requires elaborate,point-by-point fabrication.Herein,a spontaneous yet controllable strategy is developed to achieve surface microstructure engineering through a natural surface phenomenon similar to ion secretion-precipitation,that is,coupled dissolution-precipitation.A series of hierarchical microstructures on mineral surfaces in fluids with tunable morphology,orientation,dimension,and spatial distribution are achieved by simply controlling initial dissolution and fluid chemistry.In seawater,long-range ordered film of vertically aligned brucite flakes forms through interfacial dissolution,nucleation,and confinement-induced orientation of flakes with vertically grown{110}plane,on the edge of which,fusiform aragonite epitaxially precipitates.With negligible initial surface dissolution,prismatic aragonite epitaxially grows on a calcite polyhedron-packed surface.By tuning fluid chemistry,closely packed calcite polyhedron and loosely packed calcite micro-pillars are engineered through rapid and retarded precipitation,respectively.Surprisingly,the spontaneously grown microstructures resemble those deliberately created by human or found in nature,and tremendously modulate surface functionality.These findings open new possibilities for facile and customizable engineering of microstructural surfaces,hierarchical heterostructures,and biomimetic materials.

Rational surface charge engineering of haloalkane dehalogenase for boosting the enzymatic performance in organic solvent solutions

Biocatalysis in organic solvents(OSs)has numerous important applications,but native enzymes in OSs often exhibit limited catalytic performance.Herein,we proposed a computation-aided surface charge engineering strategy to improve the catalytic performance of haloalkane dehalogenase DhaA in OSs based on the energetic analysis of substrate binding to the DhaA surface.Several variants with enhanced OS resistance were obtained by replacing negative charged residues on the surface with positive charged residue(Arg).Particularly,a four-substitution variant E16R/E93R/E121R/E257R exhibited the best catalytic performance(five-fold improvement in OS resistance and seven-fold half-life increase in 40%(vol)dimethylsulfoxide).As a result,the overall catalytic performance of the variant could be at least 26 times higher than the wild-type DhaA.Fluorescence spectroscopy and molecular dynamics simulation studies revealed that the residue substitution mainly enhanced OS resistance from four aspects:(a)improved the overall structural stability,(b)increased the hydrophobicity of the local microenvironment around the catalytic triad,(c)enriched the hydrophobic substrate around the enzyme molecule,and(d)lowered the contact frequency between OS molecules and the catalytic triad.Our findings validate that computationaided surface charge engineering is an effective and ingenious rational strategy for tailoring enzyme performance in OSs.

In situ surface engineering enables high interface stability and rapid reaction kinetics for Ni-rich cathodes

Layered oxide cathodes with high Ni content promise high energy density and competitive cost for Li-ion batteries(LIBs).However,Ni-rich cathodes suffer from irreversible interface reconstruction and undesirable cracking with severe performance degradation upon long-term operation,especially at elevated temperatures.Herein,we demonstrate in situ surface engineering of Ni-rich cathodes to construct a dual ion/electron-conductive NiTiO 3 coating layer and Ti gradient doping(NC90–Ti@NTO)in parallel.The dual-modification synergy helps to build a thin,robust cathode–electrolyte interface with rapid Li-ion transport and enhanced reaction kinetics,and effec-tively prevents unfavorable crystalline phase transformation during long-term cycling under harsh environments.The optimized NC90–Ti@NTO delivers a high reversible capacity of 221.0 mAh g^(-1) at 0.1C and 158.9 mAh g^(-1) at 10C.Impressively,it exhibits a capacity retention of 88.4%at 25?C after 500 cycles and 90.7%at 55?C after 300 cycles in a pouch-type full battery.This finding provides viable clues for stabilizing the lattice and interfacial chemistry of Ni-rich cathodes to achieve durable LIBs with high energy density.

Promotion of reactive oxygen species activated by nanosilver surface engineering for resistant bacteria-infected skin tissue therapy

Nanosilver has been regarded as a promising alternative to traditional antibiotics for fighting pathogenassociated infections due to its efficacy toward a broad spectrum of pathogens.However,bacterial resistance to nanosilver has emerged recently.In this contribution,a surface engineering strategy based on N-halamine chemistry to address bacterial resistance to nanosilver was proposed.Using 1,3-dichloro-5,5-dimethylhydantoin(DCDMH)as an N-halamine source,AgCI nanodots were deposited on the surface of Ag nano wires(Ag NWs)via in situ redox reaction to prepare AgCl-on-Ag NWs.After in vitro and in vivo tests,AgCl-on-Ag NWs effectively inactivated two antibiotic-resistant bacteria,ampicillinresistant Escherichia coli(AREC)and methicillin-resistant Staphylococcus aureus(MRSA)with the minimum bactericidal concentration(MBC)as low as 10μg·ml~(-1)and exhibited good biosafety against normal cells.The experimental and theoretical tests demonstrated that AgCl-onAg NWs worked on AREC and MAS A by generating high level of reactive oxygen species under visible light irradiation,coupled with the sustained Ag ion release.Meanwhile,the antibacterial mechanism of AgCl-on-Ag NWs against MRSA was verified at the gene level by transcriptome analysis(RNA sequencing).Moreover,the fullthickness defect model verified that AgCl-on-Ag NWs reduced inflammatory cell infiltration and dramatically accelerated wound healing.This work provides a synergistic mechanism based on nanosilver surface engineering to eradicate the resistant bacteria that can alleviate drug resistance and develop an innovative approach for the treatment of bacterial infections.

Surface engineering towards high-energy carbon cathode for advanced aqueous zinc-ion hybrid capacitors

Opportunities coexist with challenges for the development of carbon-based cathodes with a high energy density applied for zinc ion hybrid capacitors(ZIHCs).In the present study,a facile and effective surface engineering approach is demonstrated to greatly improve the energy storage ability of commercial carbon paper(CP)in ZIHC.Benefiting from the introduced oxygen functional groups,larger surface area and improved surface wettability upon air calcination,the assembled aqueous ZIHC with the functionalized carbon paper(FCP)exhibits a much higher areal capacity of 0.22 mAh/cm^(2)at 1 mA/cm^(2),outperforming the counterpart with blank CP by over 5000 times.More importantly,a superior energy density and power density of 130.8μWh/cm^(2)and 7460.5μW/cm^(2),are respectively delivered.Furthermore,more than 90%of the initial capacity is retained over 10000 cycles.This surface engineering strategy to improve the energy storage capability is potentially applicable to developing a wide range of high-energy carbon electrode materials.

Surface engineering and the application of laser-based processes to stents-A review of the latest development

Late in-stent thrombus and restenosis still represent two major challenges in stents’design.Surface treatment of stent is attracting attention due to the increasing importance of stenting intervention for coronary artery diseases.Several surface engineering techniques have been utilised to improve the biological response in vivo on a wide range of biomedical devices.As a tailorable,precise,and ultra-fast process,laser surface engineering offers the potential to treat stent materials and fabricate various 3D textures,including grooves,pillars,nanowires,porous and freeform structures,while also modifying surface chemistry through nitridation,oxidation and coatings.Laser-based processes can reduce the biodegradable materials’degradation rate,offering many advantages to improve stents’performance,such as increased endothelialisation rate,prohibition of SMC proliferation,reduced platelet adhesion and controlled corrosion and degradation.Nowadays,adequate research has been conducted on laser surface texturing and surface chemistry modification.Laser texturing on commercial stents has been also investigated and a promotion of performance of laser-textured stents has been proved.In this critical review,the influence of surface texture and surface chemistry on stents performance is firstly reviewed to understand the surface characteristics of stents required to facilitate cellular response.This is followed by the explicit illustration of laser surface engineering of stents and/or related materials.Laser induced periodic surface structure(LIPSS)on stent materials is then explored,and finally the application of laser surface modification techniques on latest generation of stent devices is highlighted to provide future trends and research direction on laser surface engineering of stents.

Accurate construction of cell membrane biomimetic graphene nanodecoys via purposeful surface engineering to improve screening efficiency of active components of traditional Chinese medicine

Biomimetic nanoengineering presents great potential in biomedical research by integrating cell membrane(CM) with functional nanoparticles. However, preparation of CM biomimetic nanomaterials for custom applications that can avoid the aggregation of nanocarriers while maintaining the biological activity of CM remains a challenge. Herein, a high-performance CM biomimetic graphene nanodecoy was fabricated via purposeful surface engineering, where polyethylene glycol(PEG) was used to modifying magnetic graphene oxide(MGO) to improve its stability in physiological solution, so as to improve the screening efficiency to active components of traditional Chinese medicine(TCM). With this strategy, the constructed PEGylated MGO(PMGO) could keep stable at least 10 days, thus improving the CM coating efficiency. Meanwhile, by taking advantage of the inherent ability of He La cell membrane(HM) to interact with specific ligands, HM-camouflaged PMGO showed satisfied adsorption capacity(116.2 mg/g) and selectivity. Finally, three potential active components, byakangelicol, imperatorin,and isoimperatorin, were screened from Angelica dahurica, whose potential antiproliferative activity were further validated by pharmacological studies. These results demonstrated that the purposeful surfaceengineering is a promising strategy for the design of efficient CM biomimetic nanomaterials, which will promote the development of active components screening in TCM.

Surface engineering of synthetic nanopores by atomic layer deposition and their applications

In the past decade, nanopores have been developed extensively for various potential applications, and their performance greatly depends on the surface properties of the nanopores. Atomic layer deposition （ALD） is a new technology for depositing thin films, which has been rapidly developed from a niche technology to an established method. ALD films can cover the surface in confined regions even in nanoscale conformally, thus it is proved to be a powerful tool to modify the surface of the synthetic nanopores and also to fabricate complex nanopores. This review gives a brief introduction on nanopore synthesis and ALD fundamental knowledge, and then focuses on the various aspects of synthetic nanopores processing by ALD and their applications, including single-molecule sensing, nanofiuidic devices, nanostructure fabrication and other applications.

Materials and surface engineering to control bacterial adhesion and biofilm formation： A review of recent advances

Bacterial adhesion to surfaces and subsequent biofilm formation are a leading cause of chronic infections and biofouling. These processes are highly sensitive to environmental factors and present a challenge to research using traditional approaches with uncontrolled surfaces. Recent advances in materials research and surface engineering have brought exciting opportunities to pattern bacterial cell clusters and to obtain synthetic biofilms with well-controlled cell density and morphology of cell clusters. In this article, achievements in this field directions. we will review the recent and comment on the future

Surface engineering on segmented copper-iron nanowires arrays

Surface engineering that could modulate the surface shape to be endowed with the high specific surface ratio,abundant chemical dangling bonds and improved defects exposure is highly desired and needs further exploring.Here,we report a facile strategy of surface engineering on decorating the controllable segmented copper-iron nanowires arrays(Cu-Fe NWs)with their respective hydroxides.Specifically,the pristine segmented Cu-Fe NWs are firstly synthesized via sequentially electrodepositing Cu NWs and Fe NWs inside the nanochannels of anode aluminum oxide(AAO)template.Subsequently,the surface and interface of Cu-Fe NWs are wet-chemically etched,in which the metallic Cu and Fe are partially converted into Cu(OH)_(x)nano-fibrous roots(NFRs)and FeO(OH)_(y)nanoparticles(NPs),and finally decorate around the respective outer-surface of Cu NWs and Fe NWs segments.As one case of the applications in hydrogen evolution reaction(HER),our surface-modified Cu-Fe NWs exhibit improved catalytic activity compared with Fe NWs.

In-situ selective surface engineering of graphene micro-supercapacitor chips

Surface modification of graphene oxide(GO)is a powerful strategy to develop its energy density for electrochemical energy storage.However,pre-modified GO always exhibits unsatisfactory hydrophilia and its ink-relevant utilization is extremely limited.Although GO ink is widely utilized in fabricating micro energy storage devices via extrusion-based 3D-printing,simultaneously obtaining satisfactory hydrophilia and high energy density still remains a challenge.In this work,an in-situ surface engineering strategy was employed to enhance the performance of GO micro-supercapacitor chips.Three dimensionally printed GO micro-supercapacitor chips were treated with pyrrole monomer to achieve selective and spontaneous anchoring of polypyrrole on the microelectrodes without affecting interspaces between the finger electrodes.The interface-reinforced graphene scaffolds were edge-welded and exhibited a considerably improved specific capacitance,from 13.6 to 128.4 mF·cm^(-2).These results are expected to provide a new method for improving the performance of micro-supercapacitors derived from GO inks and further strengthen the practicability of 3D printing techniques in fabricating energy storage devices.

Interface and surface engineering of black phosphorus: a review for optoelectronic and photonic applications

Since being rediscovered as an emerging 2D material,black phosphorus(BP),with an extraordinary energy structure and unusually strong interlayer interactions,offers new opportunities for optoelectronics and photonics.However,due to the thin atomic body and the ease of degradation with water and oxides,BP is highly sensitive to the surrounding environment.Therefore,high-quality engineering of interfaces and surfaces plays an essential role in BP-based applications.In this review,begun with a review of properties of BP,different strategies of interface and surfaces engineering for high ON-OFF ratio,enhanced optical absorption,and fast optical response are reviewed and highlighted,and recent state-of-the-art advances on optoelectronic and photonic devices are demonstrated.Finally,the opportunities and challenges for future BP-related research are considered.

Engineering homotype heterojunctions in hard carbon to induce stable solid electrolyte interfaces for sodium-ion batteries

Developing effective strategies to improve the initial Coulombic efficiency(ICE)and cycling stability of hard carbon(HC)anodes for sodium-ion batteries is the key to promoting the commercial application of HC.In this paper,homotype heterojunctions are designed on HC to induce the generation of stable solid electrolyte interfaces,which can effectively increase the ICE of HC from 64.7%to 81.1%.The results show that using a simple surface engineering strategy to construct a homotypic amorphous Al_(2)O_(3) layer on the HC could shield the active sites,and further inhibit electrolyte decomposition and side effects occurrence.Particularly,due to the suppression of continuous decomposition of NaPF 6 in ester-based electrolytes,the accumulation of NaF could be reduced,leading to the formation of thinner and denser solid electrolyte interface films and a decrease in the interface resistance.The HC anode can not only improve the ICE but elevate its sodium storage performance based on this homotype heterojunction composed of HC and Al_(2)O_(3).The optimized HC anode exhibits an outstanding reversible capacity of 321.5mAhg^(−1) at 50mAg^(−1).The cycling stability is also improved effectively,and the capacity retention rate is 86.9%after 2000 cycles at 1Ag^(−1) while that of the untreated HC is only 52.6%.More importantly,the improved sodium storage behaviors are explained by electrochemical kinetic analysis.