Electrochemical Active Area Research Articles

Enhanced electrocatalytic performance and exceptional durability facilitate the effective degradation of m-dinitrobenzene wastewaters utilizing a novel SS/PbO2-Y2O3-SiC electrode

The intrinsic toxicity of m-dinitrobenzene (m-DNB) to human health and the environment has made dealing with m-DNB pollution a major concern. Herein, a novel hydrophobic anodic electrode SS/PbO2-Y2O3-SiC doped with Y and SiC was constructed via a simple electrodeposition strategy for efficient degradation of m-DNB. With a dense-uniform structure and hydrophobic surface, such SS/PbO2-Y2O3-SiC electrode exhibits obviously lower activation energy (8.17kJmol−1) and charge transfer resistance (1.15 Ω cm2), higher electrochemical active area (46.14 cm2) and stability (359 d), in comparison to SS/PbO2. The m-DNB removal efficiency of the as-prepared SS/PbO2-Y2O3-SiC anode was significantly increased to 96.4% in 180minutes, and the degradation reaction-order was determined to be 0.9559, which was in accordance with the quasi-first-order reaction kinetics. These are the possible degradation pathways of m-DNB under the action of both cathodic and anodic reactions, according to the GC-MS results. The -NO2 group of m-DNB was first reduced to the -NH2 group at the cathode surface, and then the m-phenylenediamine generated at the cathode was sequentially oxidised by the hydroxyl radicals generated from the anodic electrochemical process, resulting in the generation of H2O and CO2 at the anode surface. Additionally, the Assessment Software Tool (TEST) shows that the SS/PbO2-Y2O3-SiC anode can effectively reduce the risk and harm of m-DNB to the overall environment. This study offers novel perspectives on the development of a highly efficient PbO2 electrode for the degradation of m-DNB pollutants.

Snowflake Iron Oxide Architectures: Synthesis and Electrochemical Applications

The synthesis and characterization of iron oxide nanostructures, specifically snowflake architecture, are investigated for their potential applications in electrochemical sensing systems. A Raman spectroscopy analysis reveals phase diversity in the synthesized powders. The pH of the synthesis affects the formation of the hematite (α-Fe2O3) and goethite (α-FeOOH). Scanning electron microscopy (SEM) images confirm the distinct morphologies of the particles, which are selectively obtained through recrystallization during the elongated reaction time. An electrochemical analysis demonstrates the differing behaviors of the particles, with synthesis pH affecting the electrochemical activity and surface area differently for each shape. Cyclic voltammetry measurements reveal reversible dopamine detection processes, with snowflake iron oxide showing lower detection limits than a mixture of snowflakes and cube-like particles. This research contributes to understanding the relationship between iron oxide nanomaterials’ structural, morphological, and electrochemical properties. It offers practical insights into their potential applications in sensor technology, particularly dopamine detection, with implications for biomedical and environmental monitoring.

Preparation of rGO/CAU-10 anchored PdPbBi composites and their electrocatalytic ethylene glycol properties

An effective method to improve the catalytic performance of electrocatalytic alcohol oxidation by establishing strong interfacial interactions through novel carrier materials and polymetallic alloys. In this paper, novel polyhedral metal–organic framework Al-based [Al(OH)(mBDC)] (CAU-10) composites with PdPbBi trimetallic particles embedded in folded graphene oxide (rGO) modified by a simple hydrothermal reaction were prepared and applied to the electrocatalytic oxidation reaction of ethylene glycol. The results of electrochemical tests showed that the trimetallic catalysts exhibited excellent electrocatalytic activity compared to commercial Pd/C. In particular, PdPbBi@rGO/CAU-10 has the highest peak current density of 241.82 mA cm−2, which is 8.97 times higher than that of Pd/C (26.92 mA cm−2), and the largest electrochemical active area (ECSA) value of 88.12 mA cm−2, which is 2.40 times higher than that of Pd/C (36.75 mA cm−2). This outstanding electrocatalytic activity is mainly attributed to the polyhedral structure of CAU-10 composite carriers and the abundance of oxygen-containing atoms, which is conducive to the homogeneous loading of metals, at the same time, the strong electronic effect between Pd, Pb and Bi and the abundance of oxygen-containing species provide significant enhancement of electrocatalytic activity and stability, which provides an important reference for the development of electrocatalysts for ethylene glycol fuel cells.

Lifetime evaluation and material failure analysis of a PEMFC prepared using commercial materials

ABSTRACT Hydrogen fuel cells are vital for green energy to replace traditional energy. However, their lifetime is an important factor limiting their development. In this study, commercial materials were used to prepare proton exchange membrane fuel cells (PEMFCs), and pure oxygen was used as the cathode gas to accelerate their lifetime evaluation. The components of the membrane electrode assembly were characterized, and significant thinning was observed in the local proton exchange membrane (PEM). Therefore, the uniformity of the internal conditions of the fuel cell is the key to ensure a long lifetime. The hydrophilicity of the gas diffusion layers increased as the carbon disorder increased via the adsorption of hydrophilic chain segments produced by PEM degradation. The growth of platinum particles in the catalyst layer reduced the electrochemical active area of the catalyst, but the reduction rate slowed and then stabilized. This study of the lifetime of PEMFCs and changing properties of commercial materials clarifies the existing problems of fuel cells and contributes to the development of long-life fuel cells.

CuS nanoparticle/TiO2 nanosheets heterojuncture boosting paired electrosynthesis of formate

There is still a gap in research on the use of TiO2 as a multiphase catalyst for electrocatalysis. This paper explores the boosting effect of TiO2 nanosheets (NSs) in CuS/TiO2 NSs bifunctional catalysts which enhances their electrocatalytic formate production in both anodic methanol oxidation reaction (MOR) and cathodic carbon dioxide reduction reaction (CO2R). The boosting effect of TiO2 nanosheet is ascribed to the in-built CuS/TiO2 heterojunctions which have abundant heterointerface boundaries, adjusted electrolyte/catalyst environment, improved electrochemical active area as well as facile electron transfer. The cathodic CO2RR with CuS/TiO2 NSs showed a formate Faraday efficiency (FE formate) of 75 % at −0.9 V (vs. RHE), while the anodic MOR exhibited 97 % FE formate at 1.7 V (vs. RHE). Particularly, paired electrolysis of formate was realized in an H-type cell through simultaneous cathodic CO2RR and anodic MOR, achieving a total FE formate of 168.7 % at 10 mA cm−2.

Exploring electrochemical kinetic behaviors and interfacial charge transfer of pure and Ni-doped ZnFe2O4 nanoparticles-based sensing nanoplatform for ultra-sensitive detection of chloramphenicol

ZnFe2O4 (ZFO) nanomaterial was doped with a divalent transition metal cation of Ni2+ (NixZn1-xFe2O4, x=0, 0.2, 0.4, and 0.8) and characterized by various analytical techniques. Powder X-ray diffraction revealed the formation of a single-phase cubic spinel structure, while the stabilization of crystal structure for Ni2+-doped samples was observed. The average crystalline size, d-spacing, and lattice parameters increased with increasing in Ni2+ concentration within NixZn1-xFe2O4, due to differences in the ionic radius, the cation distribution at A-B sites, and the creation of surface oxygen vacancies within ZFO structure. From electrochemical measurements, NixZn1-xFe2O4-based electrodes showed excellent enhancements in charge transfer ability and conductivity with the highest rate constant (0.018 ms−1), the lowest peak-to-peak separation (206 mV), the lowest Rct (118 Ω), and the largest electrochemical active area (0.248 cm2), compared to that of bare SPE. Among them, Ni0.8Zn0.2Fe2O4/SPE provided outstanding electrochemical behaviors and achieved the best sensing performance with the widened concentration linear range from 0.25 to 50 μM and a rather low detection limit of 0.2 μM for chloramphenicol detection. The most important reason for this positive advance comes from the unique synergistic effects of Ni doping into the ZFO host structure. The excellent enhancements in adsorption capacity (Г) (1.4 times higher), number of oxygen vacancies, charge transfer rate constant (approximately 1.15 times higher), and catalytic rate constant (30 times greater) were recorded at Ni-doped ZFO-based electrodes, compared to pure ZFO-based electrode. Furthermore, the detailed hypotheses and possible mechanisms explaining these impressive enhancements were explored. Our work provides insight into the correlation between the Ni-doping and electrochemical characteristics, which has implications for tailoring the electrochemical performance of spinel ferrites across diverse applications and the design of novel spinel ferrite nanomaterials.

Sucrose-based reticulated vitreous carbon modified with N-doped TiO2 as an adsorbent and photocatalyst: Enhanced removal of methyl orange from aqueous solutions

A novel and low-cost 3D reticulated vitreous carbon (RVC) was synthesized and modified with (N-TiO2) to obtain an RVC/N-TiO2 composite, which was employed to remove methyl orange in an aqueous solution. This material was synthesized using the sacrificial template method and impregnated with an environmentally friendly sucrose resin, followed by N-TiO2 impregnation by dip-coating technique. SEM-EDS characterization confirmed the uniform covering of the TiO2, and XRD, Raman, and XPS evinced the presence of anatase and rutile polymorphs in the film and the N-doping, respectively. N-TiO2 coating onto RVC provides a higher specific surface area and electrochemical active area, boosting the wettability and the adsorption capacity. Additionally, this film favoured the photoelectrochemical response of the composite and the generation of •OH radicals. The adsorption, desorption, and photocatalytic studies demonstrated that >95 % decolorization of MO was achieved in 30 min without light irradiation and that >95.5 % degradation was attained in 120 min under visible light. The foam demonstrated reusability for over five cycles of adsorption/desorption of MO, with a capacity to recover up to 99 % of the dye after the first cycle and up to 94.07 % after the fifth cycle. Meanwhile, the minimal desorption of the dye (2.5 %) after illumination confirmed the photocatalytic degradation. This indicates that the process was not merely adsorption but also photocatalytic degradation.

Band structure regulation for improving the photoinduced cathodic protection performance of TiO2/ZnxIn2S3+x heterojunctions

The degree of band matching is crucial for the photoelectric conversion performance of heterojunctions. In this work, TiO2/ZnxIn2S3+x (TO/ZIS-X, X=1, 2, 3, 4) heterostructures and their electrochemical and photoelectrochemical tests were studied. According to the energy band analysis of a series of TO/ZIS-X, it is found that I-type heterojunction can be formed between TO and ZIS-1, while Z-type heterojunction would be formed between TO and ZIS-2, ZIS-3 and ZIS-4. The photoinduced potential drop associated with current density of TO/ZIS-2 in 3.5 wt% NaCl are 505.82 mV and 18.61 μA·cm−2, respectively. This result is much higher than those of homogeneous TO and single-phase ZIS-X. The desirable photoelectrochemical cathodic protection performance of the photoelectrode is owing to the loading of ZnxIn2S3+x, which broadens the light absorption threshold and improves the electrochemical activity area. Besides, the construction of Z-type heterojunction retains the photogenerated electrons/holes with strong reduction/oxidation ability, which greatly promotes the photoelectrochemical cathodic protection capability on 316 L stainless steel.

Size-Dependence of the Electrochemical Activity of Platinum Particles in the 1 to 2 Nanometer Range

Monodisperse Pt nanoparticles supported on carbon (Pt/C) were prepared via an impregnation method. By changing the concentration of the platinum precursor in the initial reagent mixture, the average particle size (d) could be controlled to within a narrow range of less than 2 nm. The specific activity (SA) of these materials, when applied to the oxygen reduction reaction (ORR), increased rapidly with d in the range below 1.8 nm, with a maximum SA at d = 1.3 nm. This value is approximately four times that of a commercial Pt/CB catalyst. The electrochemical active area, ECAA (electrochemical surface area (ECSA)/specific surface area (SSA) × 100), decreased drastically from 100% with decreases in d below 1.3 nm. In this study, we present a correlation between SA and ECAA as a means of determining the appropriate d for polymer electrolyte fuel cells (PEFCs) and propose an optimal size.

Efficient electrochemical oxidation of antibiotic wastewater using a graphene-loaded PbO2 membrane anode: Mechanisms and applications

This paper aims to develop a flow-through electrochemical system with a series of graphene nanoparticles loaded PbO2 reactive electrochemical membrane electrodes (GNPs-PbO2 REMs) on porous Ti substrates with pore sizes of 100, 150, 300 and 600 μm, and apply them to treat antibiotic wastewater. Among them, the GNPs-PbO2 with Ti substrate of 150 μm (Ti-150/GNPs-PbO2) had superior electrochemical degradation performance over the REMs with other pore sizes due to its smaller crystal size, larger electrochemical active specific area, lower charge-transfer impedance and larger oxygen evolution potential. Under the relatively optimized conditions of initial pH of 5, current density of 15 mA cm−2, and membrane flux of 4.20 m3 (m2·h)−1, the Ti-150/GNPs-PbO2 REM realized 99.34% of benzylpenicillin sodium (PNG) removal with an EE/O of 6.52 kWh m−3. Its excellent performance could be explained as the increased mass transfer. Then three plausible PNG degradation pathways in the flow-through electrochemical system were proposed, and great stability and safety of Ti-150/GNPs-PbO2 REM were demonstrated. Moreover, a single-pass Ti-150/GNPs-PbO2 REM system with five-modules in series was designed, which could consistently treat real antibiotic wastewater in compliance with disposal requirements of China. Thus, this study evidenced that the flow-through electrochemical system with the Ti-150/GNPs-PbO2 REM is an efficient alternative for treating antibiotic wastewater.

Mn incorporated RuO2 nanocrystals as an efficient and stable bifunctional electrocatalyst for oxygen evolution reaction and hydrogen evolution reaction in acid and alkaline

The development of efficient and stable bifunctional overall water-splitting is a crucial goal for clean and renewable energy, which is a challenging task. Herein, we report an Mn-incorporated RuO2 (Mn-RuO2) catalyst for highly efficient electrocatalytic oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in acid and alkaline media. Benefiting from a more electrochemical active area with the incorporation of Mn, the Mn-RuO2 required an overpotential of 200 mV to attain a current density of 10 mA/cm2 for OER in acid. DFT result indicates that the doping of Mn into RuO2 can enhance the OER activity. An acidic overall water-splitting electrolyzer with good stability constructed by bifunctional Mn-RuO2 only requires a cell voltage of 1.50 V to afford 10 mA/cm2 and can operate stably for 50 h at 50 mA/cm2, which is better than the state-of-the-art Ru-based catalyst. Additionally, the Mn-RuO2 exhibits excellent HER and OER activity in alkaline media, and it shows superior activity and durability for overall water-splitting, only needing a cell voltage of 1.49 V to attain 10 mA/cm2. The present work provides an efficient approach to designing and constructing efficient Ru-based electrocatalysts for overall water-splitting.

A “two cooking with one fish” strategy for modulating both polyaniline cathode and zinc anode towards enhanced kinetics and cycling stability for aqueous zinc ion batteries

The adverse stability of both polyaniline (PANI) and Zn anode remains a challenge to the long−term cyclability and rate capability of aqueous Zn−PANI batteries. Herein, a “two–cooking with one fish” strategy is presented to modulate both PANI cathode and Zn anode, in which nanoscale graphene sheets in cathode can promote ordered growth of PANI array, being conducive to provide large electrochemical active area and efficient transport pathways and alleviate volume variation during repeated charging/discharging process. Meanwhile, the honeycomb–like structure of graphene sheets as protective layer can accelerate zinc ion transport kinetics and suppress side reactions and zinc dendrite growth. Consequently, the optimized G/Zn symmetric cell delivers a remarkable lifespan over 1000 h at 1 mA cm−2 with 1 mAh cm−2. Furthermore, the assembled PANI/G/CC||G/Zn battery could deliver a specific capacity of 265.8 mAh g−1 at 0.2 A g−1, excellent rate capability (145.5 mAh g−1 at 20 A g−1), a maximum energy density of 246.9 W h kg−1 and power density of 8675.9 W kg−1, and especially capacity retention of 91.1 % after 10000 cycles. Combining with additional merits of low cost, eco–friendliness, and safe operation, our design will shed light on resolving the issues on cyclability and rate capability of aqueous Zn−PANI batteries.

Highly sensitive methyl parathion electrochemical sensor designed from expired mung bean-derived porous carbon embellished with cerium oxide nanoparticles

Methyl parathion (MP) is one kind of highly toxic, efficient, and broad-spectrum organic phosphorus insecticides, which may prevent and control various pests on crops. However, the unscientific usage of MP has caused serious harm to humans and ecological environment. It is very necessary to design a sensitive and selective MP analysis method to ensure the food safety and life health. In this work, we reported a low-cost and environmental-friendly strategy to prepare the expired mung bean derived porous carbon (EMBPC) with interconnected carbon conductive network and large specific surface area, which was further decorated by cerium oxide (CeO2) nanoparticles. EMBPC possessed good conductivity property and electrochemical active area, which effectively boosted the charge transfer efficiency. CeO2 nanoparticles with good biocompatibility and high catalytic capacity promoted the efficient adsorption of MP on the surface of sensing electrode due to the affinity of CeO2 nanoparticles towards the phosphate groups of MP. Furthermore, EMBPC with porous carbon conductive structure could effectively make up for the inherent disadvantage of CeO2 nanoparticles in the term of electrical conductivity. The fabricated EMBPC@CeO2/GCE sensor showed highly sensitive MP detection property with low limit of detection (LOD) of 9.028 nM. The satisfactory repeatability, reproducibility, and anti-interference ability could be achieved at the fabricated MP electrochemical sensor. For the detection of MP in food samples, the EMBPC@CeO2/GCE sensor showed satisfactory recovery rates of 95.25–112.31 % and low RSD of 1.76–4.05 %, which suggested the good application prospect of the EMBPC@CeO2/GCE sensor.

CuO nanostructures on N-doped carbon cloth for flexible enzyme-free glucose sensing

The optimization of sensing material nanostructures can improve the interfacial properties sensing materials, which is an effective tactic for enhancing the sensing performance of materials. In this study, different CuO nanostructures were in situ grown onto N-doped carbon cloth (NCC) by hydrothermal method as modified electrodes for glucose sensor. The use of NCC endowed the electrodes with excellent flexibility and conductivity, and also provided more attachment points for the growth of CuO nanostructures. Meanwhile, CuO nanostructures could be regulated by the addition of organic acid as structural inducers, and the glucose sensing performances of electrodes modified by different CuO nanostructures were studied. The results showed that CuO nanostructures were uniformly grown on NCC, and the optimized CuO nanostructure had a smaller size and a higher electrochemical active area. The modified electrode with the optimized CuO nanostructures exhibited good electrochemical performances, high sensitivity of 6.408 mA cm−2 mM−1, low detection limit of 0.33 μM and excellent stability for glucose sensing. This work presents an effective and simple method for preparing flexible self-supporting electrodes with controllable nanostructures and good interface properties, expanding a potential pathway for the development of flexible glucose sensor.

Electrode microstructure design to improve effective utilization of Fe-N/C catalysts towards oxygen reduction reaction process

Fe-N/C materials have shown intrinsic activities comparable to Pt/C catalysts for oxygen reduction reaction on rotating ring-disk electrodes (RRDE). However, due to the insufficient three-phase interfaces (TPIs) and high oxygen transport resistance (RT), the high intrinsic activity cannot be sufficiently utilized in electrodes, resulting in a gap between the intrinsic catalytic activity on RRDE and the performance in devices. To expand the TPIs and promote oxygen transport, a novel electrode with a transition layer structure is proposed to disperse the active sites. The dispersion degree of active sites is optimized by tuning the solid–liquid interfacial energy between the ink solvent and the substrate. A high electrochemical active area of 1264 cm2 and a low RT of 2.0 s cm−1 are achieved for the electrode prepared by an alcohol-rich ink. The simulation and experimental results demonstrate that the microstructure can benefit the extension of TPIs and facilitate oxygen transport in the air cathode, ultimately achieving efficient utilization of catalytic activities. A maximum power density of 35.4 mW cm−2 is achieved in a membrane-less direct formate fuel cell, surpassing most congeneric devices. Our approach clarifies the relationship between TPI construction, mass transport, and electrode microstructure, which successfully exploits the intrinsic activity on air cathodes and improves the power generation ability.

Preparation of Ti4O7/h‐BN self‐supported ceramic photoelectrode and its photoelectrocatalytic performance for water purification

AbstractThe construction of high‐efficiency self‐supported ceramic photoelectrode based on ideal semiconductor materials is essential for achieving effective degradation of pollutants by photoelectrocatalysis (PEC) technology. Herein, a Ti4O7/h‐BN composite ceramic photoelectrode with a unique microstructure was fabricated by a step‐by‐step calcination process and used in PEC water pollution remediation. The PEC activity of Ti4O7 ceramic photoelectrode could be enhanced by introducing hexagonal boron nitride (h‐BN) nanoparticles on the surface. The most optimized Ti4O7/h‐BN photoelectrode exhibited the decolorization rate of active brilliant blue KN‐R at about 97.79% in 30 min. The PEC activities could remain stable during five degradation cycles. The excellent photoelectrocatalytic performance of Ti4O7/h‐BN ceramic photoelectrode could be attributed to the low Tafel slope, low charge transfer resistance, large electrochemical active area, and excellent photo‐generated carrier separation efficiency. A type‐II heterojunction was formed between the Ti4O7 and h‐BN, which caused more effective carrier separation and enhanced the generation of dominant active species •O2− and h+. This work provided a mature synthesis strategy of Ti4O7/h‐BN self‐supported ceramic photoelectrodes with excellent practical application prospects to achieve superior PEC performance for water purification.

Ti3C2Tx/laser-induced graphene-based micro-droplet electrochemical sensing platform for rapid and sensitive detection of benomyl

The design and fabrication of high-performance electrode devices are highly important for the practical application of electrochemical sensors. In this study, flexible three-dimensional porous graphene electrode devices were first facilely fabricated using common laser ablation technique at room temperature. After then, hydrophilic two-dimensional MXene (Ti3C2Tx) nanosheet was decorated on the surface of the laser-induced graphene (LIG), resulting in disposable Ti3C2Tx/LIG electrode devices. After introducing Ti3C2Tx nanosheet, the electrochemical active area, electron transfer ability of LIG electrode device and its adsorption efficiency toward organic pesticide benomyl was significantly boosted. As a result, the fabricated Ti3C2Tx/LIG electrode device exhibited significantly enhanced electrocatalytic activity toward benomyl oxidation. Based on this, a novel and ultra-sensitive electrochemical platform for micro-droplet detection of benomyl was achieved in the range of 10 nM–6000 nM with detection sensitivity of 169.9 μA μM−1 cm−2 and detection limit of 5.8 nM. Considering the low-cost Ti3C2Tx/LIG electrode devices are rarely used for electrochemical analysis, we believed this research work will contribute to exploring the broader application of MXene/LIG electrode devices in the field of electrochemical sensing.

CuCo2O4 nanoneedle arrays growth on carbon cloth as a non-enzymatic electrochemical sensor with low detection limit ketoprofen recognition.

An electrochemical sensor for detecting ketoprofen was constructed by in-situ grown copper cobaltate (CuCo2O4) nanoneedle arrays on a carbon cloth (CC) substrate. The resulting porous nanoneedle arrays not only expose numerous electrochemically active sites but also significantly enhance the electrochemical apparent active area and current transmission efficiency. By leveraging its electrochemical properties, the sensor achieves an impressive detection limit for ketoprofen of0.7 pM, with a linear range spanning from 2 pM ~ 2 µM. Furthermore, the sensor exhibits remarkable reproducibility, anti-interference capabilities, and stability. Notably, the developed sensor also performed ketoprofen detection on real samples (including drug formulations and wastewater) and demonstrated excellent recognition ability. These exceptional performances can be attributed to the direct growth of CuCo2O4 nanoneedle arrays on the CC substrate, which facilitates a robust electrical connection, provides abundant electrocatalytic active sites, and expands the apparent active area. Consequently, these improvements contribute to the efficient trace detection capabilities of the ketoprofen sensor.

Mo-doping and construction of the heterostructure between NiFe LDH and NiSx co-trigger the activity enhancement for overall water splitting

To reduce the preparation cost of high-purity hydrogen, it is necessary to search suitable non-precious metal catalysts with high activity and robust stability. Herein, two means (heteroatom-doping and the heterostructure construction) were adopted together to improve the dual-function activity of NiFe LDH which was widely used in water electrolysis. Mo doped NiFe LDH nanoflowers were firstly generated by hydrothermal reaction, and then NiSx was modified on the petals via electrodeposition. Finally, the obtained NF/Mo-NiFe LDH/NiSx with large electrochemical active area exhibits the expected electrochemical performance with the overpotential at 100 mA cm−2 of 169 and 249 mV for hydrogen evolution (HER) and oxygen evolution reaction (OER) respectively. Assembling NF/Mo-NiFe LDH/NiSx into a two-electrode device for the integral water electrolysis, it just requires a cell voltage of 1.69 V to drive a current density of 100 mA cm−2, and keeps stable after 50-hour continuous operation in 1.0 M KOH. Mo-doping not only regulates the electronic structure of the transition metals and reduces the energy barrier of HER intermediates, but also facilitates the generation of reactive sites for OER. Meanwhile, the construction of heterointerface ensures the synergism between NiSx and Mo-NiFe LDH and accelerates the electron transfer across interfaces, thus enhancing the bifunctional performance.

Highly Ordered Hierarchical Macro-Mesoporous Carbon-Supported Cobalt Electrocatalyst for Efficient Oxygen Evolution Reaction.

Metal-organic frameworks (MOFs) and their derivatives have been extensively employed in Oxygen Evolution Reaction (OER) catalysts due to their significantly larger specific surface areas, distinct metal centers, and well-organized porous structures. However, the microporous structure of MOFs and their derivatives presents mass transfer resistance, limiting their further development. Drawing inspiration from hierarchical structures allowing for the transport and exchange of substances in the biological world, we designed and fabricated biomimetic layered porous structures within ZIF-67 and its derivatives. Based on this, we achieved a three-dimensional ordered layered porous nitrogen-doped carbon-coated magnetic cobalt catalyst (3DOLP Co@NDC) with a biomimetic pore structure. It is found that the 3DOLP Co@NDC (352 mV @10 mA cm-1) was better than Co@NDC (391 mV @10 mA cm-1). The introduction of a three-dimensional ordered layered porous structure is conducive to increasing the specific surface area of the material, increasing the electrochemical active area, and improving the catalytic performance of the material. The introduction of a three-dimensional ordered layered porous structure would help to build a bionic grade pore structure. The existence of biomimetic grade pore structure can effectively reduce the mass transfer resistance, improve the material exchange efficiency, and accelerate the reaction kinetics.