Enhancing capacitive deionization performance and cyclic stability of nitrogen-doped activated carbon by the electro-oxidation of anode materials

Electrode materials with high desalination capacity and long-term cyclic stability are the focus of capacitive deionization(CDI) community. Understanding the causes of performance decay in traditional carbons is crucial to design a high-performance material. Based on this, here, nitrogen-doped activated carbon(NAC) was prepared by pyrolyzing the blend of activated carbon powder(ACP) and melamine for the positive electrode of asymmetric CDI. By comparing the indicators changes such as conductivity, salt adsorption capacity, pH, and charge efficiency of the symmetrical ACP-ACP device to the asymmetric ACP-NAC device under different CDI cycles, as well as the changes of the electrochemical properties of anode and cathode materials after long-term operation, the reasons for the decline of the stability of the CDI performance were revealed. It was found that the carboxyl functional groups generated by the electro-oxidation of anode carbon materials make the anode zero-charge potential(E_(pzc)) shift positively,which results in the uneven distribution of potential windows of CDI units and affects the adsorption capacity. Furthermore, by understanding the electron density on C atoms surrounding the N atoms, we attribute the increased cyclic stability to the enhanced negativity of the charge of carbon atoms adjacent to quaternary-N and pyridinic-oxide-N.

Kinetic-Thermodynamic Promotion Engineering toward High-Density Hierarchical and Zn-Doping Activity-Enhancing ZnNiO@CF for High-Capacity Desalination

Despite the promising potential of transition metal oxides(TMOs)as capacitive deionization(CDI)electrodes,the actual capacity of TMOs electrodes for sodium storage is significantly lower than the theoretical capacity,posing a major obstacle.Herein,we prepared the kinetically favorable Zn_(x)Ni_(1−x)O electrode in situ growth on carbon felt(Zn_(x)Ni_(1−x)O@CF)through constraining the rate of OH^(−)generation in the hydrothermal method.Zn_(x)Ni_(1−x)O@CF exhibited a high-density hierarchical nanosheet structure with three-dimensional open pores,benefitting the ion transport/electron transfer.And tuning the moderate amount of redox-inert Zn-doping can enhance surface electroactive sites,actual activity of redox-active Ni species,and lower adsorption energy,promoting the adsorption kinetic and thermodynamic of the Zn_(0.2)Ni_(0.8)O@CF.Benefitting from the kinetic-thermodynamic facilitation mechanism,Zn_(0.2)Ni_(0.8)O@CF achieved ultrahigh desalination capacity(128.9 mgNaCl g^(-1)),ultra-low energy consumption(0.164 kW h kgNaCl^(-1)),high salt removal rate(1.21 mgNaCl g^(-1) min^(-1)),and good cyclability.The thermodynamic facilitation and Na^(+)intercalation mechanism of Zn_(0.2)Ni_(0.8)O@CF are identified by the density functional theory calculations and electrochemical quartz crystal microbalance with dissipation monitoring,respectively.This research provides new insights into controlling electrochemically favorable morphology and demonstrates that Zn-doping,which is redox-inert,is essential for enhancing the electrochemical performance of CDI electrodes.

Customized modulation on plasma uniformity by non-uniform magnetic field in capacitively coupled plasma

A two-dimensional fluid model based on COMSOL Multiphysics is developed to investigate the modulation of static magnetic field on plasma homogeneity in a capacitively coupled plasma(CCP)chamber. To generate a static magnetic field, direct current is applied to a circular coil located at the top of the chamber. By adjusting the magnetic field's configuration, which is done by altering the coil current and position, both the plasma uniformity and density can be significantly modulated. In the absence of the magnetic field, the plasma density exhibits an inhomogeneous distribution characterized by higher values at the plasma edge and lower values at the center. The introduction of a magnetic field generated by coils results in a significant increase in electron density near the coils. Furthermore, an increase in the sets of coils improves the uniformity of the plasma. By flexibly adjusting the positions of the coils and the applied current,a substantial enhancement in overall uniformity can be achieved. These findings demonstrate the feasibility of using this method for achieving uniform plasma densities in industrial applications.

Flexible capacitive pressure sensor based on interdigital electrodes with porous microneedle arrays for physiological signal monitoring

Flexible pressure sensors have many potential applications in the monitoring of physiological signals because of their good biocompatibil-ity and wearability.However,their relatively low sensitivity,linearity,and stability have hindered their large-scale commercial application.Herein,aflexible capacitive pressure sensor based on an interdigital electrode structure with two porous microneedle arrays(MNAs)is pro-posed.The porous substrate that constitutes the MNA is a mixed product of polydimethylsiloxane and NaHCO3.Due to its porous and interdigital structure,the maximum sensitivity(0.07 kPa-1)of a porous MNA-based pressure sensor was found to be seven times higher than that of an imporous MNA pressure sensor,and it was much greater than that of aflat pressure sensor without a porous MNA structure.Finite-element analysis showed that the interdigital MNA structure can greatly increase the strain and improve the sensitivity of the sen-sor.In addition,the porous MNA-based pressure sensor was found to have good stability over 1500 loading cycles as a result of its bilayer parylene-enhanced conductive electrode structure.Most importantly,it was found that the sensor could accurately monitor the motion of afinger,wrist joint,arm,face,abdomen,eye,and Adam’s apple.Furthermore,preliminary semantic recognition was achieved by monitoring the movement of the Adam’s apple.Finally,multiple pressure sensors were integrated into a 33 array to detect a spatial pressure distribu-×tion.Compared to the sensors reported in previous works,the interdigital electrode structure presented in this work improves sensitivity and stability by modifying the electrode layer rather than the dielectric layer.

Abnormal transition of the electron energy distribution with excitation of the second harmonic in low-pressure radio-frequency capacitively coupled plasmas

The self-excited second harmonic in radio-frequency capacitively coupled plasma was significantly enhanced by adjusting the external variable capacitor.At a lower pressure of 3 Pa,the excitation of the second harmonic caused an abnormal transition of the electron energy probability function,resulting in abrupt changes in the electron density and temperature.Such changes in the electron energy probability function as well as the electron density and temperature were not observed at the higher pressure of 16 Pa under similar harmonic changes.The phenomena are related to the influence of the second harmonic on stochastic heating,which is determined by both amplitude and the relative phase of the harmonics.The results suggest that the self-excited high-order harmonics must be considered in practical applications of lowpressure radio-frequency capacitively coupled plasmas.

Effect of a negative DC bias on a capacitively coupled Ar plasma operated at different radiofrequency voltages and gas pressures

The effect of a negative DC bias,|V_(dc)|,on the electrical parameters and discharge mode is investigated experimentally in a radiofrequency(RF)capacitively coupled Ar plasma operated at different RF voltage amplitudes and gas pressures.The electron density is measured using a hairpin probe and the spatio-temporal distribution of the electron-impact excitation rate is determined by phase-resolved optical emission spectroscopy.The electrical parameters are obtained based on the waveforms of the electrode voltage and plasma current measured by a voltage probe and a current probe.It was found that at a low|V_(dc)|,i.e.inα-mode,the electron density and RF current decline with increasing|V_(dc)|;meanwhile,the plasma impedance becomes more capacitive due to a widened sheath.Therefore,RF power deposition is suppressed.When|V_(dc)|exceeds a certain value,the plasma changes toα–γhybrid mode(or the discharge becomes dominated by theγ-mode),manifesting a drastically growing electron density and a moderately increasing RF current.Meanwhile,the plasma impedance becomes more resistive,so RF power deposition is enhanced with|V_(dc)|.We also found that the electrical parameters show similar dependence on|V_(dc)|at different RF voltages,andα–γmode transition occurs at a lower|V_(dc)|at a higher RF voltage.By increasing the pressure,plasma impedance becomes more resistive,so RF power deposition and electron density are enhanced.In particular,theα–γmode transition tends to occur at a lower|V_(dc)|with increase in pressure.

Structure-guided Capacitance Relationships in Oxidized Graphene Porous Materials Based Supercapacitors

Supercapacitors formed from porous carbon and graphene-oxide(GO)materials are usually dominated by either electric double-layer capacitance,pseudo-capacitance,or both.Due to these combined features,reduced GO materials have been shown to offer superior capacitance over typical nanoporous carbon materials;however,there is a significant variation in reported values,ranging between 25 and 350 F g^(−1).This undermines the structure(e.g.,oxygen functionality and/or surface area)-performance relationships for optimization of cost and scalable factors.This work demonstrates important structure-controlled charge storage relationships.For this,a series of exfoliated graphene(EG)derivatives are produced via thermal-shock exfoliation of GO precursors and following controlled graphitization of EG(GEG)generates materials with varied amounts of porosity,redox-active oxygen groups and graphitic components.Experimental results show significantly varied capacitance values between 30 and 250 F g^(−1)at 1.0 A g^(−1)in GEG structures;this suggests that for a given specific surface area the redox-active and hydrophilic oxygen content can boost the capacitance to 250–300%higher compared to typical mesoporous carbon materials.GEGs with identical oxygen functionality show a surface area governed capacitance.This allows to establish direct structure-performance relationships between 1)redox-active oxygen functional concentration and capacitance and 2)surface area and capacitance.

Machine learning techniques for prediction of capacitance and remaining useful life of supercapacitors: A comprehensive review

Supercapacitors are appealing energy storage devices for their promising features like high power density,outstanding cycling stability,and a quick charge–discharge cycle.The exceptional life cycle and ultimate power capability of supercapacitors are needed in the transportation and renewable energy generation sectors.Hence,predicting the capacitance and lifecycle of supercapacitors is significant for selecting the suitable material and planning replacement intervals for supercapacitors.In addition,system failures can be better addressed by accurately forecasting the lifecycle of SCs.Recently,the use of machine learning for performance prediction of energy storage materials has drawn increasing attention from researchers globally because of its superiority in prediction accuracy,time efficiency,and costeffectiveness.This article presents a detailed review of the progress and advancement of ML techniques for the prediction of capacitance and remaining useful life(RUL)of supercapacitors.The review starts with an introduction to supercapacitor materials and ML applications in energy storage devices,followed by workflow for ML model building for supercapacitor materials.Then,the summary of machine learning applications for the prediction of capacitance and RUL of different supercapacitor materials including EDLCs(carbon based materials),pesudocapacitive(oxides and composites)and hybrid materials is presented.Finally,the general perspective for future directions is also presented.

Porous Graphene-Based Electrodes for Fiber-Shaped Supercapacitors with Good Electrical Conductivity

Graphene fibers(GFs)are ideal electrodes for f ibrous supercapacitors because of their excellent mechanical and electrical properties.However,the actual specific s urface area(SSA)of GFs is low due to the restacking of g raphene sheets,which limits the capacitance enhancement o f GFs.One of the effective ways to increase the SSA of GFs is to construct a porous fiber structure,but it disrupts t he conductive pathway and adversely affects the electrochemical(EC)performance of GFs.Therefore,a wet-spun porous GF electrode coated with polypyrrole(PPy)was reported in this paper.The resulting electrode exhibits an areal specific capacitance of 31.25 mF·cm^(-2)and a good c ycling stability with a capacitance retention rate of 95%after 5000 charge/discharge cycles.These indicate that porous structures and PPy coating can synergistically improve the EC performance of GFs.

Perspective on ultrathin layered Ni-doped MoS_(2) hybrid nanostructures for the enhancement of electrochemical properties in supercapacitors

Over the last two decades,extensive study has been done on two-dimensional Molybdenum Sulphide(MoS_(2))due to its outstanding features in energy storage applications.Although MoS_(2)has a lot of active sulphur edges,the presence of inactive surfaces leads to limit conductivity and efficiency.Hence,in this article,we aimed to promote the additional active sites by doping various weight percentages(2%,4%,6%,8%and 10%)of Nickel(Ni)into the MoS_(2)matrix by simple hydrothermal technique,and their doping effects were investigated with the help of Physio-chemical analyses.X-ray diffraction(XRD)pattern,Raman,and chemical composition(XPS)analyses were used to confirm the Ni incorporation in MoS_(2)nanosheets.Microscopic investigations demonstrated that Ni-doped MoS_(2)nanosheets were vertically aligned with enhanced interlayer spacing.Cyclic voltammetry,Galvanostatic charge-discharge,and electrochemical impedance spectroscopy investigations were used to characterize the electrochemical characteristics.The 6%Ni-doped MoS_(2)electrode material showed better CSPof 528.7 F/g@1 A/g and excellent electrochemical stability(85%of capacitance retention after 10,000 cycles at 5 A/g)compared to other electrode materials.Furthermore,the solid-state asymmetric supercapacitor was assembled using Nidoped MoS_(2)and graphite as anode and cathode materials and analysed the electrochemical properties in the two-electrode system.To determine the impact of the Ni-atom on the MoS_(2)surface,firstprinciples computations were performed.Further,it was examined for electronic band structure,the projected density of states(PDOS)and Bader charge transfer analyses.

Preparation of Eco-Friendly High-Performance Manganese Dioxide Supercapacitors by Linear Sweep Voltammetry

In this paper,the non-polluting,non-toxic,and eco-friendly material-MnO_(2)electrodes were deposited on three-dimensional porous nickel(Ni)foam by linear sweep voltammetry,and the entire electrodeposition process did not require sintering of the material,which was fast and convenient while avoiding unnecessary energy consump-tion and thus was environmentally friendly.Scanning electron microscopy(SEM)and transmission electron microscopy were used to examine the surface and microscopic characteristics of each sample(TEM).Chronoam-perometry(CA),cyclic voltammetry(CV),galvanostatic charge/discharge(GCD),and electrochemical impedance spectroscopy(EIS)were then used to determine the electrochemical characteristics of the manufactured samples.The result suggests that the MnO_(2)-sv80 electrode sample at a scan rate of 80 mV/s^(−1)has excellent performance for the supercapacitor electrode.The specific capacitance was as high as 531.4 F g^(−1)at a current density of 1 A g^(−1)and remained at 223.2 F g^(−1)at an ultra-high current density of 20 A g^(−1),with capacitance retention of 42%.

Boosting Capacitive Deionization Performance of Commercial Carbon Fibers Cloth via Structural Regulation Based on Catalytic-Etching Effect

Monolithic carbon electrodes with robust mechanical integrity and porous architecture are highly desired for capacitive deionization but remain challenging.Owing to the excellent mechanical strength and electroconductivity,commercial carbon fibers cloth demonstrates great potential as high-performance electrodes for ions storage.Despite this,its direct application on capacitive deionization is rarely reported in terms of limited pore structure and natural hydrophobicity.Herein,a powerful metal-organic framework-engaged structural regulation strategy is developed to boost the desalination properties of carbon fibers.The obtained porous carbon fibers features hierarchical porous structure and hydrophilic surface providing abundant ions-accessible sites,and continuous graphitized carbon core ensuring rapid electrons transport.The catalytic-etching mechanism involving oxidation of Co and subsequent carbonthermal reduction is proposed and highly relies on annealing temperature and holding time.When directly evaluated as a current collector-free capacitive deionization electrode,the porous carbon fibers demonstrates much superior desalination capability than pristine carbon fibers,and remarkable cyclic stability up to 20 h with negligible degeneration.Particularly,the PCF-1000 showcases the highest areal salt adsorption capacity of 0.037 mg cm^(−2) among carbon microfibers.Moreover,monolithic porous carbon fibers-carbon nanotubes with increased active sites and good structural integrity by in-situ growth of carbon nanotubes are further fabricated to enhance the desalination performance(0.051 mg cm^(−2)).This work demonstrates the great potential of carbon fibers in constructing high-efficient and robust monolithic electrode for capacitive deionization.

Exploration of the Exceptional Capacitive Deionization Performance of CoMn_(2)O_(4) Microspheres Electrode

The“battery type”inorganic electrode has been demonstrated the highly efficient sodium ion intercalation capacity for capacitive deionization.In this work,the CoMn_(2)O_(4)(CMO)microspheres with porous core-shell structure are prepared via co-precipitation and followed by annealing.The effects of annealing temperatures on the morphology,pore structure,valence state,and electrochemical behavior of CMO are explored.As electrode for capacitive deionization,the salt removal capacity and current efficiency of optimized AC||CMO device reaches up to 60.7 mg g^(−1) and 97.6%,respectively,and the capacity retention rate is 74.1%after 50 cycles.Remarkably,both the in-situ X-ray diffraction and ex-situ X-ray diffraction analysis features that the intercalation/de-intercalation of sodium ions are governed by(103)and(221)crystal planes of CMO.Accordingly,the density functional theory calculations realize that the adsorption energies of Na+onto(103)and(221)crystal planes are higher than that of any other crystal planes,manifesting the priorities in adsorption of sodium atoms.Furthermore,the X-ray photoelectron spectra of pristine and post-CMO electrode highlights that the reversible conversion of Mn^(3+)/Mn^(4+)couple is resulted from the intercalation/de-intercalation of Na^(+),while this is irreversible for Co^(3+)/Co^(2+)couple.Beyond that,the CMO electrode has been proven the selectivity removal of Na^(+) over K^(+)and Mg^(2+)in a multi-cation stream.

Capacitive energy storage from single pore to porous electrode identified by frequency response analysis

Rate capability,peak power,and energy density are of vital importance for the capacitive energy storage(CES)of electrochemical energy devices.The frequency response analysis(FRA)is regarded as an efficient tool in studying the CES.In the present work,a bi-scale impedance transmission line model(TLM)is firstly developed for a single pore to a porous electrode.Not only the TLM of the single pore is reparameterized but also the particle packing compactness is defined in the bi-scale.Subsequently,the CES properties are identified by FRA,focused on rate capability vs.characteristic frequency,peak power vs.equivalent series resistance,and energy density vs.low frequency limiting capacitance for a single pore to a porous electrode.Based on these relationships,the CES properties are numerically simulated and theoretically predicted for a single pore to a porous electrode in terms of intra-particle pore length,intra-particle pore diameter,inter-particle pore diameter,electrolyte conductivity,interfacial capacitance&exponent factor,electrode thickness,electrode apparent surface area,and particle packing compactness.Finally,the experimental diagnosis of four supercapacitors(SCs)with different electrode thicknesses is conducted for validating the bi-scale TLM and gaining an insight into the CES properties for a porous electrode to a single pore.The calculating results suggest,to some extent,the inter-particle pore plays a more critical role than the intra-particle pore in the CES properties such as the rate capability and the peak power density for a single pore to a porous electrode.Hence,in order to design a better porous electrode,more attention should be given to the inter-particle pore.

Recent progress in flexible capacitive sensors:Structures and properties

The future intelligent era that will be brought about by 5G technology can be well predicted.For example,the connection between humans and smart wearable devices will become increasingly more intimate.Flexible wearable pressure sensors have received much attention as a part of this process.Nevertheless,there is a lack of complete and detailed discussion on the recent research status of capacitive pressure sensors composed of polymer composites.Therefore,this article will mainly discuss the key concepts,preparation methods and main performance of flexible wearable capacitive sensors.The concept of a processing“toolbox”is used to review the developmental status of the dielectric layer as revealed in highly cited literature from the past five years.The preparation methods are categorized into types of processing:primary and secondary.Using these categories,the preparation methods and structure of the dielectric layer are discussed.Their influence on the final capacitive sensing behavior is also addressed.Recent developments in the electrode layer are also systematically reviewed.Finally,the results of the above discussion are summarized and future development trends are discussed.

N-Doped rGO-Like Carbon Prepared from Coconut Shell:Structure and Specific Capacitance

An rGO−like carbon compound has been synthesized from biomass,i.e.,old coconut shell,by a carbonization process followed by heating at 400°C for 5 h.The nitrogen doping was achieved by adding the urea(CH4N2O)and stirring at 70°C for 14 h.The morphology and structure of the rGO-like carbon were investigated by electron microscopies and Raman spectroscopy.The presence of C-N functional groups was analyzed by Fourier transform infrared and synchrotron X-ray photoemission spectroscopy,while the particle and the specific capacitance were measured by particle sizer and cyclic voltammetry.The highest specific capacitance of 72.78 F/g is achieved by the sample with 20%urea,having the smallest particles size and the largest surface area.The corresponding sample has shown to be constituted by the appropriate amount of C–N pyrrolic and pyridinic defects.

Effect of parallel resonance on the electron energy distribution function in a 60 MHz capacitively coupled plasma

In general,as the radio frequency(RF)power increases in a capacitively coupled plasma(CCP),the power transfer efficiency decreases because the resistance of the CCP decreases.In this work,a parallel resonance circuit is applied to improve the power transfer efficiency at high RF power,and the effect of the parallel resonance on the electron energy distribution function(EEDF)is investigated in a 60 MHz CCP.The CCP consists of a power feed line,the electrodes,and plasma.The reactance of the CCP is positive at 60 MHz and acts like an inductive load.A vacuum variable capacitor(VVC)is connected in parallel with the inductive load,and then the parallel resonance between the VVC and the inductive load can be achieved.As the capacitance of the VVC approaches the parallel resonance condition,the equivalent resistance of the parallel circuit is considerably larger than that without the VVC,and the current flowing through the matching network is greatly reduced.Therefore,the power transfer efficiency of the discharge is improved from 76%,70%,and 68%to 81%,77%,and 76%at RF powers of 100 W,150 W,and 200 W,respectively.At parallel resonance conditions,the electron heating in bulk plasma is enhanced,which cannot be achieved without the VVC even at the higher RF powers.This enhancement of electron heating results in the evolution of the shape of the EEDF from a biMaxwellian distribution to a distribution with the smaller temperature difference between high-energy electrons and low-energy electrons.Due to the parallel resonance effect,the electron density increases by approximately 4%,18%,and 21%at RF powers of 100 W,150 W,and 200 W,respectively.

Nano-single-crystal-constructed submicron MnCO_(3) hollow spindles enabled by solid precursor transition combined Ostwald ripening in situ on graphene toward exceptional interfacial and capacitive lithium storage

Hollow structuring has been identified as an effective strategy to enhance the cycling stability of electrodes for rechargeable batteries due to the outstanding volume expansion buffering efficiency,which motivates ardent pursuing on the synthetic approaches of hollow materials.Herein,an intriguing route,combining solid precursor transition and Ostwald ripening(SPTOR),is developed to craft nano single-crystal(SC)-constructed MnCO_(3) submicron hollow spindles homogeneously encapsulated in a reduced graphene oxide matrix(MnCO_(3) SMHSs/rGO).It is noteworthy that the H-bonding interaction between Mn_(3)O_(4) nanoparticles(NPs)and oxygen-containing groups on GO promotes uniform anchoring of Mn_(3)O_(4) NPs on GO,mild reductant ascorbic acid triggers the progressive solid-to-solid transition from Mn_(3)O_(4) NPs to MnCO_(3) submicron solid spindles(SMSSs)in situ on GO,and the Ostwald ripening process induces the gradual dissolution of interior polycrystals of MnCO_(3) SMSSs and subsequent recrystallization on surface SCs of MnCO_(3) SMHSs.Remarkably,MnCO_(3) SMHSs/rGO delivers a 500th lithium storage capacity of 2023 mAh g^(-1) at 1000 mAg^(-1),which is 10 times higher than that of MnCO_(3) microspheres/rGO fabricated from a conventional Mn^(2+)salt precursor(202 mAh g^(-1)).The ultrahigh capacity and ultralong lifespan of MnCO_(3) SMHSs/rGO can be primarily attributed to the superior reaction kinetics and reversibility combined with exceptional interfacial and capacitive lithium storage capability,enabled by the fast ion/electron transfer,large specific surface area,and robust electrode pulverization inhibition efficacy.Moreover,fascinating in-depth lithium storage reactions of MnCO_(3) are observed such as the oxidation of Mn^(2+)in MnCO_(3) to Mn^(3+)in charge process after long-term cycles and the further lithiation of Li_(2)CO_(3) in discharge process.As such,the Carbon Energy.SPTOR approach may represent a viable strategy for crafting various hollow functional materials with metastable nanomaterials as precursors.

Calcitriol induces post-thawed bovine sperm capacitation

Background:Capacitation is a set of physiological changes sperms undergo to acquire fertilizing capacity.In vivo,this process is directly associated with high calcium levels in sperm cytoplasm.Calcitriol,the vitamin D hypercalcemic metabolite,is related to human sperm motility,capacitation,and acrosome reaction.This work aimed to study the effect of calcitriol on bull sperm quality parameters and capacitation.Methods:One million freezethawed spermatozoa were obtained from different bulls and treated with 20 nM of calcitriol for 30 min.Untreated cells(negative control)and treated ones with calcitriol or heparin(100μg/mL,positive capacitation control)were evaluated for motility,viability,and functional parameters.Menadione(70μM,30 min)treatment was included as a reactive oxygen species(ROS)positive sperm agent.Results:The results elucidated that sperm exposed to 20 nM calcitriol showed higher viability,vigor,and capacitation than their positive and negative controls.The percentage of sperm with intact plasma and acrosome membranes,mitochondrial membrane potential(ΔΨm),and phosphatidylserine externalization was similar in all the conditions evaluated,while ROS production was higher with heparin and menadione-treated groups than the calcitriol group or negative control.Conclusion:Our results indicate that calcitriol induces the capacitation of thawed bull spermatozoa and maintains acceptable values of progressive motility,viability,and vigor without altering key biological parameters such as redox status,ΔΨm,and cell death.

Integration of pore structure modulation and B,N co-doping for enhanced capacitance deionization of biomass-derived carbon

Biomass-derived carbon has demonstrated great potentials as advanced electrode for capacitive deionization(CDI),owing to good electroconductivity,easy availability,intrinsic pores/channels.However,conventional simple pyrolysis of biomass always generates inadequate porosity with limited surface area.Moreover,biomass-derived carbon also suffers from poor wettability and single physical adsorption of ions,resulting in limited desalination performance.Herein,pore structure optimization and element co-doping are integrated on banana peels(BP)-derived carbon to construct hierarchically porous and B,N co-doped carbon with large ions-accessible surface area.A unique expansionactivation(EA)strategy is proposed to modulate the porosity and specific surface area of carbon.Furthermore,B,N co-doping could increase the ions-accessible sites with improved hydrophilicity,and promote ions adsorption.Benefitting from the synergistic effect of hierarchical porosity and B,N co-doping,the resultant electrode manifest enhanced CDI performance for NaCl with large desalination capacity(29.5 mg g^(-1)),high salt adsorption rate(6.2 mg g^(-1)min^(-1)),and versatile adsorption ability for other salts.Density functional theory reveals the enhanced deionization mechanism by pore and B,N co-doping.This work proposes a facile EA strategy for pore structure modulation of biomass-derived carbon,and demonstrates great potentials of integrating pore and heteroatoms-doping on constructing high-performance CDI electrode.