Efficient Electron Transfer Pathways Research Articles

Enhancing the oxygen evolution reaction activity of Iron (oxy) hydroxide by increasing reactive sites with morphology modulation

Nonprecious transition metal (oxy)hydroxides play a vital role in accelerating the kinetics of sluggish oxygen evolution reaction (OER). The fast electron transfer from the electrocatalyst material surface to the electrode is key to obtaining improved OER activity in terms of improved reaction kinetics and reduced overpotential. Therefore, it is highly desirable to design electrocatalysts with efficient electron transport properties. Here, an approach of modulation of the morphology of Iron (oxy)hydroxide through the incorporation of Cr is used to obtain high electrocatalytic activity. The incorporation of Cr resulted in the modified morphology of Iron (oxy)hydroxide with the formation of a porous pit-like structure which offers large reactive sites to effectively adsorb the reactants and allow an efficient electron transfer pathway from electrocatalyst to circuit through Ni foam electrode. A 50% Cr incorporated electrocatalyst (Fe5.0Cr5.0 (oxy)hydroxide) exhibits excellent OER activity with an overpotential of 237mV and 297mV at current densities of 10 and 100mAcm─2, respectively owing to fast electron transport from electrocatalyst to substrate due to formation of porous pit-like structure. Furthermore, Fe5.0Cr5.0 electrocatalyst shows high durability of over 100h at 10mAcm─2. The enhanced OER activity is attributed to the effect of Cr incorporation and morphology modulation which helps to modulate the electronic structure as well as electrocatalytic active sites of Fe (oxy)hydroxide. The systematic incorporation and modulation of morphology pave the way for designing future electrocatalysts for various electrochemical activities.

Covalent organic framework with extraordinary intrinsic catalytic activity for electrochemical sensing of iodide ions

Environmental conservation and food safety have aroused enormous concerns owing to their close relationship with human health. Iodide ion (I−) could result in serious diseases in mankind. Thus, it is challenging and essential to develop an effective approach to capture and detect I−. Herein, the TT-COF(Zn) material prepared using 2,3,6,7-tetra (4-formyl phenyl) tetrathiafulvalene (TTF) and 5,10,15,20-tetrakis(para-aminophenyl) porphyrin Zinc (II) (TPZ) as building blocks were designed directly as electrode modified material for electrochemical sensing of I−. Combining the meritsofTPZ and TTF to construct the intrinsic efficient electron-transfer pathways, as well as the advantages of porous channel and single-site catalysis of COF, TT-COF(Zn) material-modified electrode showed excellent electrocatalytic performance towards the redox reaction of I−, which makes it a sensitive sensing platform for the electrochemical quantification of I−. After a series of optimization experiments, the I− sensor demonstrated a wide linear range (0.02–15 mM), low detection limit (3.15 μM), as well as other good sensing features. The proposed sensor also performed well in the determination of I− in real river samples. This work not only offers a simple method to assay I− effectively but also paves a way for the strategical design and synthesis of COFs for electrochemical sensing applications.

Surface C[tbnd]N bonds mediate photocatalytic CO2 reduction into efficient CH4 production in TiO2-decorated g-C3N4 nanosheets

Graphitic carbon nitride (g-C3N4, CN) has garnered considerable attention in the field of photocatalysis due to its favorable band gap and high specific surface area. However, its primary practical limitation lies in the strong radiative recombination of lone pair (LP) electronic states, leading to limited efficiency in separating photogenerated carriers and subsequently diminishing photocatalytic performance. In this study, we devised and synthesized a heterojunction photocatalytic system comprising TiO2 nanosheets supported on modified g-C3N4 (MCN), designated as MCN/TiO2. The presence of CN functional groups on the tri-s-triazine nitrogen captures photogenerated electrons by modifying LP electronic states, resulting in a reduction in the fluorescence emission intensity of g-C3N4. Simultaneously, it forms chemical bonds with the supported TiO2 nanosheets, creating an efficient electron transfer pathway for the accumulation of photogenerated electrons at the active Ti sites. Experimentally, the MCN/TiO2 photocatalytic system exhibited optimal performance in CO2 reduction. The CH4 production rate reached 26.59 μmol g−1 h−1, surpassing that of TiO2 and CN/TiO2 by approximately 8 and 3 times, respectively. Furthermore, this photocatalytic system demonstrated exceptional photostability over five cycles, each lasting 4 h. This research offers a valuable approach for the efficient separation and transfer of photogenerated carriers in composite materials based on g-C3N4.

Regulating localized state electron and ordered electron transfer in Cu2Se using Indium element for efficient heterogeneous Fenton-like process

Local electron density at the reaction center atoms is closely related to the H2O2 activation performance of a heterogeneous Fenton-like catalyst. However, the random electron transfer often restricts the oriented electron delivery to the active center. In this study, we proposed that only efficient electrons and their ordered transfer were desirable to boost Cu(II)/Cu(I) cycle for H2O2 activation based on regulation of local electron density and electron transfer efficiency of Cu atoms in Cu2Se. Experimental results and density function theory (DFT) calculation proved that Indium atom can drive electrons to accumulate on Cu active center and provide an efficient electron transfer pathway in CuInSe2 (from Se → Cu to In → Se → Cu). Hence, compared with Cu2Se, more reductive electrons can participate in the H2O2 activation process for CuInSe2, which resulted in much more efficient ofloxacin (OFX) degradation with a TOC removal rate up to 71.5 %. The electron exchange capacity of CuInSe2 was further regulated by changing the atomic ratios of Cu and In elements including CuInSe2, Cu1.5In0.5Se2 and Cu1.75In0.25Se2. CuInSe2 had the lowest electron exchange capacity and exhibited the highest reaction activity with a radical transformation efficiency from H2O2 of 9.83 × 10-4, in contrast, the value for Cu1.75In0.25Se2 was 2.78 × 10-4. We provided a new insight for improving the heterogeneous Fenton catalytic performance.

Heterostructure design of one-dimensional ZnO@CoNi/C multilayered nanorods for high-efficiency microwave absorption

Dimensional design and heterogeneous interface engineering are promising approaches for the fabrication of superior absorbers with high loss performance and a wide effective bandwidth. Therein, ZnO nanorods were successfully synthesized and combined with CoNi nanosheets by hydrothermal method, and PDA was then encapsulated on the surface of the material to form a unique one dimensional (1D) core-sheath structure. The extensive defects and residual functional groups are present in the calcined material, as well as the multiple heterogeneous interfaces enhance the dielectric loss induced by polarization. Simultaneously, the 1D structure wrapped with PDA offers an efficient pathway for electron transfer, hence facilitating the enhancement of conductive loss. In addition, the CoNi-LDHs sheet layer stacked on the surface not only causes multiple scattering and reflections of electromagnetic waves, but also provides magnetic losses to optimize the impedance matching. Finally, radar cross section (RCS) simulations further reveal that the composite can dissipate electromagnetic energy in practical applications. Consequently, the 1D multilayer ZnO@CoNi/C composite exhibits an optimal reflection loss of −55 dB with a thickness of 2.3 mm and an effective absorption bandwidth (EAB) value of 6.8 GHz when the filling ratio is only 20 wt%. In summary, this paper provides a new direction for the fabrication of 1D multilayer nonhomogeneous interfacial absorbers with excellent performance.

Inhibiting solubility challenges: Carbon nanotube encapsulation of stable transition metal oxides for electrochemical energy storage and conversion applications

Transition metal oxides (TMO) are commonly used catalyst materials for electrolytic water splitting. However, their solubility in alkaline electrolytes presents a significant challenge, reducing their catalytic activity. To address this issue, we have developed a technique to synthesize carbon nanotube (CNT) encapsulated Fe2O3, effectively inhibiting the dissolution of Fe2O3. The formation of Fe2O3@CNT not only provides an efficient pathway for electron transfer, but also increases its active surface area. The results demonstrate that the excellent catalytic performance of Fe2O3@CNT in both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), with overpotentials of 249 mV and 208 mV, respectively. Moreover, the CNT encapsulation technique exhibits universality, as evidenced by Co3O4@CNT, which displays a specific capacitance of 1800 F g−1 at 1 A g−1, and retains 125.5 % of its initial capacitance after 9000 cycles in a two-electrode system. Overall, our study highlights the role of CNT encapsulation in promoting the catalytic and energy storage performance of TMO, revealing a novel approach to enhancing their stability.

Tuning charge transfer between size-controlled Pt cluster and N vacancy engineered ultrathin g-C3N4 for efficient photocatalytic hydrogen evolution

Rational design and development of metal-cluster co-catalysts with regulated charge transfer interface is an effective strategy to fabricate highly active photocatalysis. Here, Pt clusters are elaborately incorporated onto N vacancy engineered ultrathin g-C3N4 (vUCN) by a facile photo-deposition method. The targeted vUCN-300Pt with cluster size of 1.1 nm and dispersion density of 104 μg m−2 exhibits an optimal photocatalytic rate of 862.4 μmol h−1 g−1, which is approximate 40 times and 5.3 times higher than that of pristine g-C3N4 and vUCN. The inherent reason for the superior property lies on the efficient electron transfer pathway, in which electrons are effectively migrated to the surface assisted by the ultrathin structure and appropriate N vacancies, and subsequently directed towards the neighboring Pt cluster. Additionally, the light absorption ability and the proton reduction kinetics are both promoted under the collaborative optimization of the band-gap structure by Pt cluster and vUCN. Afterwards the Pt site with reduced Gibbs free energy could serve as a highly active medium for combining H* and the transferred electron to achieve efficient H2 evolution. The relevance of these findings provides useful guideline for tuning the reactive metal-support interaction (RMSI) between Pt cluster and g-C3N4-based catalysts.

Porphyrin-based covalent organic framework with self-accelerated M−N4 bimetallic active sites for enhanced electrochemical detection of trace hydrogen peroxide

The ultrasensitive detection of trace hydrogen peroxide (H2O2) has been a fascinating research topic owing to its significant application in environmental monitoring, food safety, and scientific research. In this study, bimetallic porphyrin-based covalent organic framework composites (MWCNTs@Mn/Fe-COF) was prepared by in situ polymerization of Mn porphyrin (MnPor) and Fe porphyrin (FePor) on multi-walled carbon nanotubes (MWCNTs), and a biomimetic enzyme electrochemical sensor was constructed for determination of trace H2O2. The unique topological structure features of COF and the high conductivity of MWCNTs not only ensured highly independent M−N4 electrochemical active sites, but also guaranteed efficient electron transfer pathways. Especially, the introduction of Mn sites formed a self-accelerated redox cycling between valence states, which significantly improved the electrocatalytic efficiency. Taking advantage of the above advantages, the MWCNTs@Mn/Fe-COF based sensor achieved ultrasensitive detection of H2O2 with a low detection limit of 2 nM. Moreover, the developed sensor has been successfully used to measure trace H2O2 induced by lab-equipped ultrasonic cleaners and in disinfector and apple juice. The constructed sensor in this study has potential application value in the rapid detection of trace H2O2 in real samples, which opened up a new way for the synthesis of bimetallic analog enzymes and the construction of ultra-sensitive electrochemical sensors.

Rational Design of Covalent Multiheme Cytochrome‐Carbon Dot Biohybrids for Photoinduced Electron Transfer

AbstractBiohybrid systems can combine inorganic light‐harvesting materials and whole‐cell biocatalysts to utilize solar energy for the production of chemicals and fuels. Whole‐cell biocatalysts have an intrinsic self‐repair ability and are able to produce a wide variety of multicarbon chemicals in a sustainable way with metabolic engineering. Current whole‐cell biohybrid systems have a yet undefined electron transfer pathway between the light‐absorber and metabolic enzymes, limiting rational design. To enable engineering of efficient electron transfer pathways, covalent biohybrids consisting of graphitic nitrogen doped carbon dots (g‐N‐CDs) and the outer‐membrane decaheme protein, MtrC from Shewanella oneidensis MR‐1 are developed. MtrC is a subunit of the MtrCAB protein complex, which provides a direct conduit for bidirectional electron exchange across the bacterial outer membrane. The g‐N‐CDs are functionalized with a maleimide moiety by either carbodiimide chemistry or acyl chloride activation and coupled to a surface‐exposed cysteine of a Y657C MtrC mutant. MtrC∼g‐N‐CD biohybrids are characterized by native and denaturing gel electrophoresis, chromatography, microscopy, and fluorescence lifetime spectroscopy. In the presence of a sacrificial electron donor, visible light irradiation of the MtrC∼g‐N‐CD biohybrids results in reduced MtrC. The biohybrids may find application in photoinduced transmembrane electron transfer in S. oneidensis MR‐1 for chemical synthesis in the future.

Primary charge separation in native and plant pheophytin a-modified reaction centers of Chloroflexus aurantiacus: Ultrafast transient absorption measurements at low temperature

Ultrafast transient absorption (TA) spectroscopy was used to study electron transfer (ET) at 100 K in native (as isolated) reaction centers (RCs) of the green filamentous photosynthetic bacterium Chloroflexus (Cfl.) aurantiacus. The rise and decay of the 1028 nm anion absorption band of the monomeric bacteriochlorophyll a molecule at the BA binding site were monitored as indicators of the formation and decay of the P+BA− state, respectively (P is the primary electron donor, a dimer of bacteriochlorophyll a molecules). Global analysis of the TA data indicated the presence of at least two populations of the P⁎ excited state, which decay by distinct means, forming the state P+HA− (HA is a photochemically active bacteriopheophytin a molecule). In one population (~65 %), P⁎ decays in ~2 ps with the formation of P+HA− via a short-lived P+BA− intermediate in a two-step ET process P⁎ → P+BA−→ P+HA−. In another population (~35 %), P⁎ decays in ~20 ps to form P+HA− via a superexchange mechanism without producing measurable amounts of P+BA−. Similar TA measurements performed on chemically modified RCs of Cfl. aurantiacus containing plant pheophytin a at the HA binding site also showed the presence of two P⁎ populations (~2 and ~20 ps), with P⁎ decaying through P+BA− only in the ~2 ps population. At 100 K, the quantum yield of primary charge separation in native RCs is determined to be close to unity. The results are discussed in terms of involving a one-step P⁎ → P+HA− superexchange process as an alternative highly efficient ET pathway in Cfl. aurantiacus RCs.

In situ growth of a cobalt porphyrin-based covalent organic framework on multi-walled carbon nanotubes for ultrasensitive real-time monitoring of living cell-released nitric oxide.

Nitric oxide (NO), as a critical transcellular messenger, participates in a variety of physiological and pathological processes. However, its real-time detection still faces challenges due to its short half-life and trace amounts. Here, MWCNTs@COF-366-Co was prepared by in situ growth of a cobalt porphyrin-based covalent organic framework (COF-366-Co) on multi-walled carbon nanotubes (MWCNTs), and a unique biosensing platform for ultrasensitive real-time NO determination was established. Remarkably, MWCNTs@COF-366-Co contains plenty of atomically arranged M-N4 active sites for electrocatalysis, which provides more efficient electron transfer pathways and resolves the random arrangement issue of active sites. COF-366-Co with a high surface area contains a large number of exposed active M-N4 sites, providing faster NO transport/diffusion and more efficient electron transfer pathways. Due to the synergy of atomic-level periodic structural features of COF-366-Co and high conductivity of MWCNTs, the MWCNTs@COF-366-Co electrochemical biosensor exhibited excellent NO determination performance in a wide range from 0.09 to 400 μM, with high sensitivity (8.9 μA μM-1 cm-2) and a low limit of detection (16 nM). Moreover, the biosensor has been successfully used to sensitively monitor NO molecules released from human umbilical vein endothelial cells (HUVECs). This research not only designed a multifunctional intelligent biosensor platform, but also provided a broad prospect for continuous dynamic monitoring of the activity of living cells and their released metabolites.

Ultrasound-assisted degradation of organophosphorus pesticide methidathion using CuFe2O4@SiO2-GOCOOH as a magnetic separable sonocatalyst.

Water contamination by pesticides is a critical environmental issue, necessitating the development of sustainable and efficient degradation methods. This study focuses on synthesizing and evaluating a novel heterogeneous sonocatalyst for degrading pesticide methidathion. The catalyst consists of graphene oxide (GO) decorated CuFe2O4@SiO2 nanocomposites. Comprehensive characterization using various techniques confirmed the superior sonocatalytic activity of the CuFe2O4@SiO2-GOCOOH nanocomposite compared to CuFe2O4@SiO2 alone. The enhanced performance is attributed to the combined effects of GO and CuFe2O4@SiO2, including increased surface area, enhanced adsorption capabilities, and efficient electron transfer pathways. Reaction parameters such as time, temperature, concentration, and pH significantly influenced the degradation efficiency of methidathion. Longer reaction times, higher temperatures, and lower initial pesticide concentrations favored faster degradation and higher efficiency. Optimal pH conditions were identified to ensure effective degradation. Remarkably, the catalyst demonstrated excellent recyclability, indicating its potential for practical implementation in pesticide-contaminated wastewater treatment. This research contributes to the development of sustainable methods for environmental remediation, highlighting the promising potential of the graphene oxide decorated CuFe2O4@SiO2 nanocomposite as an effective heterogeneous sonocatalyst for pesticide degradation.

Surface active-site engineering in NiCoSe2/nitrogen-doped carbon dodecahedrons for efficient triiodide reduction in photovoltaics

Constructing Pt-free counter electrode (CE) catalysts with considerable catalytic activity, conductivity, and electrochemical stability are greatly significant for improving the overall power conversion efficiency (PCE) of dye-sensitized solar cells (DSSCs). In this work, we focus on the uniformly distributing Ni and Co elements into layered hydroxide polyhedrons that stemmed from ZIF-67 to transform an active-site enriched composite of NiCoSe2 encapsulated by the derived nitrogen-doped carbon dodecahedrons (NiCoSe2/NC) through the simple pyrolysis procedure. Benefitting from the evenly distributed catalytic sites, unique structure, and positively synergy, the resultant NiCoSe2/NC displays excellent catalytic activity in triiodide reduction reaction (IRR). Consequently, DSSCs fabricated with the optimized NiCoSe2/NC yielded an impressive PCE of 9.92 %, superior to that of the traditional Pt-based devices (8.17 %). The intrinsic mechanism for superior IRR performance of NiCoSe2/NC was mainly ascribed to the favorable adsorption energy (Ead) for capturing I3−, the highly reactive metal catalytic sites at the interface, the efficient electron-transfer pathway, and the enhanced bonding interaction between I 5p and 3d states of the dual metals, as revealed by DFT calculation. It is worthy expecting to provide an extensible pathway for developing a cost-effective composite with profitable structure to guide the synthesis of efficient catalysts in catalytic fields.

Beads‐on‐string hierarchical structured electrocatalysts for efficient oxygen reduction reaction

AbstractRational design of hierarchically structured electrocatalysts is particularly important for electrocatalytic oxygen reduction reaction (ORR). Here, ZIF‐67 crystals are stringed on core–shell Ag@C nanocables using a coordination‐modulated process. Upon pyrolysis, Ag@C strings of Co nanoparticles embedded with three‐dimensional porous carbon with beads‐on‐string hierarchical structures are developed. Due to the advantages of the rich electrochemical active sites of Co‐based “beads” and the efficient electron transfer pathways via Ag@C “strings,” the resultant NH3–Ag@C@Co–N–C‐700 catalyst shows an improved electrocatalytic activity toward ORR. NH3–Ag@C@Co–N–C‐700 shows a high onset potential of 0.99 V versus RHE, a high half‐wave potential of 0.88 V versus RHE, and a large limiting current of 5.8 mA cm−2, which are better than those of commercial Pt/C electrocatalysts. Additionally, the NH3–Ag@C@Co–N–C‐700 catalyst shows high stability and preeminent methanol tolerance, which makes NH3–Ag@C@Co–N–C‐700 a promising catalyst for oxygen electrocatalysis in fuel cell applications.

Customized exogenous ferredoxin functions as an efficient electron carrier

Ferredoxin (Fdx) is regarded as the main electron carrier in biological electron transfer and acts as an electron donor in metabolic pathways of many organisms. Here, we screened a self-sufficient P450-derived reductase PRF with promising production yield of 9OHAD (9α-hydroxy4-androstene-3,17-dione) from AD, and further proved the importance of [2Fe–2S] clusters of ferredoxin-oxidoreductase in transferring electrons in steroidal conversion. The results of truncated Fdx domain in all oxidoreductases and mutagenesis data elucidated the indispensable role of [2Fe–2S] clusters in the electron transfer process. By adding the independent plant-type Fdx to the reaction system, the AD (4-androstene-3,17-dione) conversion rate have been significantly improved. A novel efficient electron transfer pathway of PRF + Fdx + KshA (KshA, Rieske-type oxygenase of 3-ketosteroid-9-hydroxylase) in the reaction system rather than KshAB complex system was proposed based on analysis of protein–protein interactions and redox potential measurement. Adding free Fdx created a new conduit for electrons to travel from reductase to oxygenase. This electron transfer pathway provides new insight for the development of efficient exogenous Fdx as an electron carrier.Graphical

The ZnO–Au-Titanium oxide nanotubes (TiNTs) composites photocatalysts for CO2 reduction application

The presence of gold nanoparticles (Au) on the zinc oxide (Zn)-titanium oxide nanotubus (TiNTs) composites to form the Z-scheme type photocatalysts has been investigated for photocatalytic reduction of CO2 to methanol. In this study, the commercial titanium dioxide powder (P-25) was first treated under a strong basic environment and applied a hydrotherrmal method to systhsize TiNTs, and calcined to use as a support. Then, various ratios of ZnO and TiNTs from 0.1 to 0.5 were also prepared by hydrothermal method to form TiNTs-ZnO-X (TZ-X, X is equal to the ZnO/TiNTs weight ratio) composites, and 1 to 5 wt % of Au were impregnated on the TiNTs-ZnO support to form the ZnO–Au-TiNTs composite photocatalysts.The catalysts will be characterized by x-ray diffraction spectroscopy (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–visible spectroscopy (UV–Vis) and photoluminescence spectroscopy (PL) techniques to determine the structures and morphology of the ZnO–Au-TiNTs composites. The catalytic results have revealed that the TZ-0.20–2 wt% Au catalyst has the best photocatalysis activity with a 7777.1μmole/(g-cat) (hr) CH3OH production yield.The formation of the ZnO–Au-TiNTs Z-scheme type heterostructure results in an efficient electron transfer pathway and electron-hole separation inside the composite catalyst which lead to a highly efficient CO2 reduction and excellent improvement in methanol yield.

Electrochemical detection of DNA by formation of efficient electron transfer pathways through adsorbing gold nanoparticles to DNA modified electrodes

The high-performance detection of nucleic acids is increasingly important in the early and accurate disease diagnosis. Herein, we describe a unique label-free electrochemical DNA biosensor, which is based on gold nanoparticles (GNPs) mediated electron transfer through a DNA monolayer modified gold electrode surface. We observed that the different states of DNA monolayers (single-strand DNA or triple-helix DNA) and the different sizes of GNPs have a significant effect on the electron transfer by the DNA modified gold electrodes. This DNA biosensing strategy avoids the complicated fabrication process of the DNA capture probes and minimizes the steps of electrode pre-treatment. Under optimal conditions, this method can sensitively and accurately detect the target DNA ranging from 10 pM to 100 nM with a detection limit of 1.47 pM.

Direct Electrochemical Protonation of Metal Oxide Particles.

Metal oxides with surface protonation exhibit versatile physical and chemical properties suitable for use in many fields. Here, we develop an electrochemical route to directly protonize the physically assembled oxide particles, such as TiO2, Nb2O5, and WO3, in a Na2SO4 neutral electrolyte, which is a result of electrochemically induced oxygen vacancies reacting with water molecules. With no need of electric connection among particles or between particles and conductive substrate, the electrochemical protonation follows a bottom-up particle-by-particle surface protonation mechanism due to the fact that the protonation inducing high surface conductivity creates an efficient electron transfer pathway among particles. Our results show that electrochemical protonation of particles provides a chance to finely functionalize the surface of a single particle by only adjusting electrode potentials. Such a facile, cost-efficient, and green route is easy to run for a large-scale production and unlocks the potential of semiconductor oxides for various applications.

One‐dimensional nanomaterial supported metal single‐atom electrocatalysts: Synthesis, characterization, and applications

AbstractMetal single‐atom catalysts (MSACs) have attracted considerable attention in the field of electrocatalysis due to their maximized atomic utilization, high activity, and superior selectivity. As a class of supported catalyst, the type of support material plays a key role in stabilizing metal single atoms (MSAs) and improving the overall catalytic performance. One‐dimensional (1D) nanomaterials are regarded as ideal supports for MSACs owing to many of their unique advantages, such as controllable surface physicochemical properties, large specific surface area, efficient electron transfer pathway, and great flexibility in element selection. Therefore, recently developed MSACs supported by various types of 1D nanostructured substrates have shown fascinating electrocatalytic performance towards a wide range of electrochemical reactions and demonstrated great potential in practical applications. In this review, we summarize recent progress of 1D nanomaterial supported MSACs, from material synthesis, characterization, and theoretical calculation to their performance in five different kinds of electrochemical applications. In particular, the major synthetic strategies of these advanced MSACs and their catalytic performance and mechanisms in various electrocatalytic reactions are extensively discussed. Finally, the remaining challenges and future prospects of 1D nanomaterial supported MSACs are provided.

Nitrogen-doped carbonaceous scaffold anchored with cobalt nanoparticles as sulfur host for efficient adsorption and catalytic conversion of polysulfides in lithium-sulfur batteries

The effective inhibition of lithium polysulfides (LiPSs) and promotion of their conversion in the redox processes is indispensable to achieve the long cycle stability and excellent rate performance of lithium-sulfur (Li-S) batteries. Especially, the generally slow electrocatalytic sulfur redox kinetics and large interfacial Li2S nucleation energy barriers have hindered the widespread application of Li-S batteries. Herein, a robust three-dimensional sulfur carrier (denoted as Co-NCNT) is well-constructed using the potassium citrate derived porous carbon sheets as substrate and the catalytic growth nitrogen-doped porous carbon nanotubes as vertical scaffolds. Such a rationally designed structure guarantees efficient electron transfer pathways and ions diffusion channels. More importantly, it is conducive to the adsorption/catalytic conversion of intermediate lithium polysulfides and the nucleation of Li2S. Due to these merits, the S@Co-NCNT cathode achieves an initial discharge capacity up to 1072.7 mAh g−1 at 1.0 C, and it can retain a high capacity of 482.9 mAh g−1 with a capacity attenuation rate of only 0.045% per cycle after 1000 cycles. Upon a high sulfur loading of 5.87 mg cm−2, the S@Co-NCNT electrode can still reach an initial capacity of 739.5 mAh g−1 at 0.3 C. Particular emphasis is that our work broadens the way to prepare well-designed carbonaceous materials sulfur host for long-life Li-S batteries.