Lignin-reinforced PVDF electrolyte for dendrite-free quasi-solid-state Li metal battery

Quasi-solid-state lithium metal batteries(QSSLMBs)assembled with polyvinylidene fluoride(PVDF)are a promising class of next-generation rechargeable batteries due to their safety,high energy density,and superior interfacial properties.However,PVDF has a series of inherent drawbacks such as low ionic conductivity,ease of crystallization,and hydrophobic character that leading to poor cell properties.To tackle these issues,a lignin-reinforced PVDF electrolyte is proposed in this work to solve these drawbacks of PVDF and enhance the comprehensive performance of QSSBs.The lithophilic polar groups of lignin can promote uniform deposition of Li on the electrodes.Cooperating with the improved mechanical properties can efficiently prevent Li dendrites penetration through the separator.In addition,more active sites provided by lignin can also enhance Li^(+)transport and lead to a faster electrochemical reaction kinetic.Benefitting from the ingenious design,Li symmetric cells with 5%lignin-PVDF quasi-solid-state electrolyte can operate for 900 h at a high current density/capacity of 5 mA·cm^(-2)/5 mAh·cm^(-2),while shortcircuiting occurs after 56 h for the counterpart(pure PVDF).Moreover,a full cell of Li/5%lignin-PVDF/LFP cell demonstrates a high capacity of 96.2 mAh·g^(-1)after 2000 cycles at 10 C.This work is expected to open up promising opportunities to develop other high-energy/power-density QSSLMBs.

Catalytic degradation of organic pollutants for water remediation over Ag nanoparticles immobilized on amine-functionalized metalorganic frameworks

Developing efficient catalysts for organic pollutants degradation is crucial for remediating the current severe water environment,yet remains a great challenge.Herein,we report silver nanoparticles immobilized on an amine-functionalized metal-organic framework(MOFs)(Ag/UiO-66-NH_(2))as a robust catalyst for the reduction of 4-nitrophenol(4-NP).The fabricated Ag/UiO-66-NH_(2)catalyst exhibits the merits of superior activities(high turnover frequency(TOF)3.2×10^(4)h^(-1)and k value 6.9×10^(-2)s^(-1)),costeffectiveness under the lowest NaBH4 concentration(n[NaBH_(4)]/n[4-NP],200),outstanding cyclability(10 recycling runs),and observable long-term durability,significantly outperforming previously reported catalytic system.The excellent degradation efficiency is ascribed to the favorable microenvironment modulation of unique MOF structure,which regulates the intrinsic properties of active sites and improves the electron-transfer process.Notably,the Ag/UiO-66-NH_(2)also promotes the catalytic degradation of several organic pollutants at room temperature and hence could find a broad application for water remediation.This work offers a new avenue for the development of high-performance MOF-based catalysts with excellent activity and durability.

Fractionational and structural characterization of lignin and its modification as biosorbents for efficient removal of chromium from wastewater:a review

The removal of chromium(Cr)from wastewater by various adsorbents has been investigated.As compared with the commercial activated carbon,the biosorbents with inexpensive and high adsorption capacities are developed from lignocellulosic wastes.Lignin,existing in lignocellulosic biomass,is the second most abundant resource in nature.Recently,lignin-based bio-sorbents were served as an advanced novel material for the metal ions and dye adsorption from wastewater.It has showed several advantages in the wastewater treatments because of the lowcost,high adsorption capacity,easy recover,and possibility of metal recovery.In this review,the isolation of lignin from lignocellulosic biomass was summarized,and the structural characteristics of lignin were comparably analyzed.The modification of lignin was performed to obtain a large surface area,strong binding-site,and high and quick adsorption properties of lignin-based adsorption materials.The adsorption efficiency of Cr ions was found to be strongly dependent on the pH of the wastewater.To further illustrate the adsorption process,the structural changes and the interactions between the metal ions and the functional groups of the lignin-based biosorbents in the adsorption process should be further investigated.Once the cost-effective and high-efficiency modification techniques are developed,lignin-based adsorbents can be expected to be the most suitable alternatives for Cr ions removal from wastewater in industry.

CoSe_(2) nanobelt coupled with CoMoO_(4) nanosheet as efficient electrocatalysts for hydrogen and oxygen evolution reaction

Designing non-noble electrocatalysts with low-cost and efficient is crucial to the development of sustainable and clean energy resources.Here,we synthesized a novel S-CoSe_(2)/CoMoO_(4) and O-CoSe_(2)/CoMoO_(4) hybrid electrocatalysts for the HER and OER,respectively.Possibly due to the synergetic chemical coupling effects between CoSe_(2)/DETA and CoMoO_(4),and the introduction of S heteroatom and oxygen vacancy,this hybrid could expose enough active edges,and then promoted the constructed hybrid displayed superior hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)catalytic performance.The S-CoSe_(2)/CoMoO_(4) sample afforded a current density of 10 mAcm^(-2) at a small overpotential of 177 mV and a small Tafel slope of 54 mV dec^(-1).Moreover,the oxidized CoSe_(2)/CoMoO_(4)(O-CoSe_(2)/CoMoO_(4))also displayed a remarkable catalytic property for OER with a small Tafel slope of 43 mV dec^(-1),as well as excellent stability in 1.0 M KOH.Therefore,this noblemetal-free and highly efficient catalyst enables prospective applications for electrochemical applications.