Ya MaZhicheng JiangYafei LuoXingjie Guo...
597-603页查看更多>>摘要：The interactions between lignin oligomers and solvents determine the behaviors of lignin oligomers self-assembling into uniform lignin nanoparticles(LNPs).Herein,several alcohol solvents,which readily interact with the lignin oligomers,were adopted to study their effects during solvent shifting process for LNPs'production.The lignin oligomers with widely distributed molecular weight and abundant guaiacyl units were extracted from wood waste(mainly consists of pine wood),exerting outstanding self-assembly capability.Uniform and spherical LNPs were generated in H2O-n-propanol cosolvent,whereas irregular LNPs were obtained in H2O-methanol cosolvent.The unsatisfactory self-assembly performance of the lignin oligomers in H2O-methanol cosolvent could be attributed to two aspects.On one hand,for the initial dissolution state,the distinguishing Hansen solubility parameter and polarity between methanol solvent and lignin oligomers resulted in the poor dispersion of the lignin oligomers.On the other hand,strong hydrogen bonds between methanol solvent and lignin oligomers during solvent shifting process,hindered the interactions among the lignin oligomers for self-assembly.
Yuhan LiZiteng RenZhengjiang HePing Ouyang...
623-658页查看更多>>摘要：Good crystallinity can reduce the charge recombination centers caused by defects,whilst structures with strong polycondensation have high charge mobility,leading to more charge transfer to the material surface for reaction.Much effort has been put into the preparation of a highly efficient g-C3N4 with defects to improve its application potential under the premise in high crystallinity.Hence,this review paper emphasizes the importance to balance the defect and crystallinity of g-C3N4.In addition,detailed discussion on the relationship between defects and activity of g-C3N4 was carried out based on its applications in environmental purification(e.g.,VOCs oxidation,NOx oxidation,H2O2 evolution,sterili-zation,pesticide oxidation)and energy conversion(H2 evolution,N2 fixation and CO2 reduction).Lastly,the challenge in developing more efficient defective g-C3N4 photocatalytic materials is summarized.
Shiwen WangZhen GengSonghu BiYuwei Wang...
659-683页查看更多>>摘要：Green hydrogen(H2)produced by renewable energy powered alkaline water electrolysis is a promising alternative to fossil fuels due to its high energy density with zero-carbon emissions.However,efficient and economic H2 production by alkaline water electrolysis is hindered by the sluggish hydrogen evolution reaction(HER)and oxygen evolution reaction(OER).Therefore,it is imperative to design and fabricate high-active and low-cost non-precious metal catalysts to improve the HER and OER performance,which affects the energy efficiency of alkaline water electrolysis.Ni3S2 with the heazlewoodite structure is a potential electrocatalyst with near-metal conductivity due to the Ni-Ni metal network.Here,the review comprehensively presents the recent progress of Ni3S2-based electrocatalysts for alkaline water electrocatalysis.Herein,the HER and OER mechanisms,performance evaluation criteria,preparation methods,and strategies for performance improvement of Ni3S2-based electrocatalysts are discussed.The challenges and perspectives are also analyzed.
Guangfu QianWei ChenJinli ChenLi Yong Gan...
684-694页查看更多>>摘要：Exploitation of oxygen evolution reaction(OER)and urea oxidation reaction(UOR)catalysts with high activity and stability at large current density is a major challenge for energy-saving H2 production in water electrolysis.Herein,we use the pyridinic-N doping carbon layers coupled with tensile strain of FeNi alloy activated by NiFe2O4(FeNi/NiFe2O4@NC)for efficiently increasing the performance of water and urea oxidation.Due to the tensile strain effect on FeNi/NiFe2O4@NC,it provides a favorable modulation on the electronic properties of the active center,thus enabling amazing OER(η100=196 mV)and UOR(E10=1.32 V)intrinsic activity.Besides,the carbon-coated layers can be used as armor to prevent FeNi alloy from being corroded by the electrolyte for enhancing the OER/UOR stability at large current density,showing high industrial practicability.This work thus provides a simple way to prepare high-efficiency catalyst for activating water and urea oxidation.
Jianjun TianChangsheng CaoYingchun HeMuhammad Imran Khan...
695-701页查看更多>>摘要：Controllable design of the catalytic electrodes with hierarchical superstructures is expected to improve their electrochemical performance.Herein,a self-supported integrated electrode(NiCo-ZLDH/NF)with a unique hierarchical quaternary superstructure was fabricated through a self-sacrificing template strategy from the metal-organic framework(Co-ZIF-67)nanoplate arrays,which features an intriguing well-defined hierarchy when taking the unit cells of the NiCo-based layered double hydroxide(NiCo-LDH)as the primary structure,the ultrathin LDH nanoneedles as the secondary structure,the mesoscale hollow plates of the LDH nanoneedle arrays as the tertiary structure,and the macroscale three-dimensional frames of the plate arrays as the quaternary structure.Notably,the distinctive structure of NiCo-ZLDH/NF can not only accelerate both mass and charge transfer,but also expose plentiful accessible active sites with high intrinsic activity,endowing it with an excellent electrochemical performance for urea oxidation reaction(UOR).Specially,it only required the low potentials of 1.335,1.368 and 1.388 V to deliver the current densities of 10,100 and 200 mA cm-2,respectively,much superior to those for typical NiCo-LDH.Employing NiCo-ZLDH/NF as the bifunctional electrode for both anodic UOR and cathodic HER,an energy-saving electrolysis system was further explored which can greatly reduce the needed voltage of 213 mV to deliver the current density of 100 mA cm-2,as compared to the conventional water electrolysis system composed of OER.This work manifests that it is prospective to explore the hierarchically nanostructured electrodes and the innovative electrolytic technologies for high-efficiency electrocatalysis.
Guoshen YangGangrui QuChi FangJie Deng...
702-712页查看更多>>摘要：The recent advances in aqueous magnesium-ion hybrid supercapacitor(MHSC)have attracted great attention as it brings together the benefits of high energy density,high power density,and synchronously addresses cost and safety issues.However,the freeze of aqueous electrolytes discourages aqueous MHSC from operating at low-temperature conditions.Here,a low-concentration aqueous solution of 4 mol L-1 Mg(ClO4)2 is devised for its low freezing point(-67 ℃)and ultra-high ionic conductivity(3.37 mS cm-1at-50 ℃).Both physical characterizations and computational simulations revealed that the Mg(C1O4)2 can effectively disrupt the original hydrogen bond network among water molecules via transmuting the electrolyte structure,thus yielding a low freezing point.Thus,the Mg(ClO4)2 electrolytes endue aqueous MHSC with a wider temperature operation range(-50 ℃-25 ℃)and a higher energy density of 103.9 Wh kg-1 at 3.68 kW kg-1 over commonly used magnesium salts(i.e.,MgSO4 and Mg(NO3)2)electrolytes.Furthermore,a quasi-solid-state MHSC based on polyacrylamide-based hydrogel electrolyte holds superior low-temperature performance,excellent flexibility,and high safety.This work pioneers a convenient,cheap,and eco-friendly tactic to procure low-temperature aqueous magnesium-ion energy storage device.
Zhifeng HuangRolf HempelmannYiqiong ZhangLi Tao...
713-722页查看更多>>摘要：Aqueous redox-active organic materials-base electrolytes are sustainable alternatives to vanadium-based electrolyte for redox flow batteries(RFBs)due to the advantages of high ionic conductivity,environmentally benign,safety and low cost.However,the underexplored redox properties of organic materials and the narrow thermodynamic electrolysis window of water(1.23 V)hinder their wide applications.Therefore,seeking suitable organic redox couples and aqueous electrolytes with a high output voltage is highly suggested for advancing the aqueous organic RFBs.In this work,the functionalized phenazine and nitroxyl radical with electron-donating and electron-withdrawing group exhibit redox potential of-0.88 V and 0.78 V vs.Ag,respectively,in"water-in-ionic liquid"supporting electrolytes.Raman spectra reveal that the activity of water is largely suppressed in"water-in-ionic liquid"due to the enhanced hydrogen bond interactions between ionic liquid and water,enabling an electrochemical stability window above 3 V."Water-in-ionic liquid"supporting electrolytes help to shift redox potential of nitroxyl radical and enable the redox activity of functionalized phenazine.The assembled aqueous RFB allows a theoretical cell voltage of 1.66 V and shows a practical discharge voltage of 1.5 V in the"water-in-ionic liquid"electrolytes.Meanwhile,capacity retention of 99.91％per cycle is achieved over 500 charge/discharge cycles.A power density of 112 mW cm-2 is obtained at a current density of 30 mA cm-2.This work highlights the importance of rationally combining supporting electrolytes and organic molecules to achieve high-voltage aqueous RFBs.
Xiaodi LiuYufeng TangDan ZhangGuangyin Liu...
723-731页查看更多>>摘要：Orthorhombic Nb2O5(T-Nb2O5)is attractive for fast-charging Li-ion batteries,but it is still hard to realize rapid charge transfer kinetics for Li-ion storage.Herein,F-doped T-Nb2O5 microflowers(F-Nb2O5)are rationally synthesized through topotactic conversion.Specifically,F-Nb2O5 are assembled by single-crystal nanoflakes with nearly 97％exposed(100)facet,which maximizes the exposure of the feasible Li+transport pathways along loosely packed 4g atomic layers to the electrolytes,thus effectively enhancing the Li+-intercalation performance.Besides,the band gap of F-Nb2O5 is reduced to 2.87 eV due to the doping of F atoms,leading to enhanced electrical conductivity.The synergetic effects between tailored exposed crystal facets,F-doping,and ultrathin building blocks,speed up the Li+/electron transfer kinetics and improve the pseudocapacitive properties of F-Nb2O5.Therefore,F-Nb2O5 exhibit superior rate capability(210.8 and 164.9 mAh g-1at 1 and 10 C,respectively)and good long-term 10 C cycling performance(132.7 mAh g-1 after 1500 cycles).
Hong QinYangzhuo HePiao XuYuan Zhu...
732-747页查看更多>>摘要：Carbon-doped copper ferrite(C-CuFe2O4)was synthesized by a simple two-step hydrothermal method,which showed enhanced tetracycline hydrochloride(TCH)removal efficiency as compared to the pure CuFe2O4 in Fenton-like reaction.A removal efficiency of 94％was achieved with 0.2 g L-1 catalyst and 20 mmol L-1 H2O2 within 90 min.We demonstrated that 5％C-CuFe2O4 catalyst in the presence of H2O2 was significantly efficient for TCH degradation under the near-neutral pH(5-9)without buffer.Multiple techniques,including SEM,TEM,XRD,FTIR,Raman,XPS Mossbauer and so on,were conducted to investigate the structures,morphologies and electronic properties of as-prepared samples.The introduction of carbon can effectively accelerate electron transfer by cooperating with Cu and Fe to activate H2O2 to generate·OH and·O2-.Particularly,theoretical calculations display that the p,p,d orbital hybridization of C,O,Cu and Fe can form C-O-Cu and C-O-Fe bonds,and the electrons on carbon can transfer to metal Cu and Fe along the C-O-Fe and C-O-Cu channels,thus forming electron-rich reactive centers around Fe and Cu.This work provides lightful reference for the modification of spinel ferrites in Fenton-like application.
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