Lignin-derived hard carbon anode with a robust solid electrolyte interphase for boosted sodium storage performance

Hard carbon is regarded as a promising anode candidate for sodium-ion batteries due to its low cost,relatively low working voltage,and satisfactory specific capacity.However,it still remains a challenge to obtain a high-performance hard carbon anode from cost-effective carbon sources.In addition,the solid electrolyte interphase(SEI)is subjected to continuous rupture during battery cycling,leading to fast capacity decay.Herein,a lignin-based hard carbon with robust SEI is developed to address these issues,effectively killing two birds with one stone.An innovative gas-phase removal-assisted aqueous washing strategy is developed to remove excessive sodium in the precursor to upcycle industrial lignin into high-value hard carbon,which demonstrated an ultrahigh sodium storage capacity of 359 mAh g^(-1).It is found that the residual sodium components from lignin on hard carbon act as active sites that controllably regulate the composition and morphology of SEI and guide homogeneous SEI growth by a near-shore aggregation mechanism to form thin,dense,and organic-rich SEI.Benefiting from these merits,the as-developed SEI shows fast Na+transfer at the interphases and enhanced structural stability,thus preventing SEI rupture and reformation,and ultimately leading to a comprehensive improvement in sodium storage performance.

Characterization and performance of Cu/ZnO/Al_2O_3 catalysts prepared via decomposition of M(Cu,Zn)-ammonia complexes under sub-atmospheric pressure for methanol synthesis from H_2 and CO_2

Methanol synthesis from hydrogenation of CO2 is investigated over Cu/ZnO/Al2O3 catalysts prepared by decomposition of M（Cu,Zn）-ammonia complexes （DMAC） at various temperatures.The catalysts were characterized in detail,including X-ray diffraction,N2 adsorption-desorption,N2O chemisorption,temperature-programmed reduction and evolved gas analyses.The influences of DMAC temperature,reaction temperature and specific Cu surface area on catalytic performance are investigated.It is considered that the aurichalcite phase in the precursor plays a key role in improving the physiochemical properties and activities of the final catalysts.The catalyst from rich-aurichalcite precursor exhibits large specific Cu surface area and high space time yield of methanol （212 g/（Lcat·h）;T=513 K,p=3MPa,SV=12000 h-1）.

2D/2D type-Ⅱ Cu2ZnSnS4/Bi2WO6 heterojunctions to promote visible-light-driven photo-Fenton catalytic activity

In this work,a set of novel Cu2ZnSnS4/Bi2WO6(CZTS/BWO)two-dimensional(2 D)/two-dimensional(2 D)type-Ⅱheterojunctions with different CZTS weight ratios(1%,2%,and 5%)were successfully synthesized via a brief secondary solvothermal process.The successful formation of the heterojunctions was affirmed by characterization methods such as X-ray photoelectron spectroscopy and high-resolution transmission electron microscopy.The photocatalytic activity results showed that the prepared CZTS/BWO heterojunctions had excellent photocatalytic behaviors for organic degradation,especially when the mass fraction of CZTS with respect to BWO in the composite was 2%.Moreover,the addition of hydrogen peroxide(H2O2)could further improve the dye and antibiotic degradation efficiencies.The reinforced photocatalytic and photo-Fenton degradation performance were primarily attributable to the introduction of BWO,which afforded increased active sites,expanded the solar spectral response range,and accelerated the cycle of Cu(Ⅱ)/Cu(Ⅰ);after four cycling times,its catalytic activity did not decrease significantly.In addition,reasonable hypotheses of the photocatalytic and photo-Fenton catalytic mechanisms were formulated.This study is expected to provide a visual approach for designing a novel photo-Fenton catalyst to jointly utilize the photocatalytic and Fenton activities,which can be better applied to the purification of residual organics in wastewater.

Plate-to-Layer Bi2MoO6/MXene-Heterostructured Anode for Lithium-Ion Batteries

Bi2MoO6 is a potentially promising anode material for lithiumion batteries(LIBs)on account of its high theoretical capacity coupled with low desertion potential.Due to low conductivity and large volume expansion/contraction during charge/discharge cycling of Bi2MoO6,effective modification is indispensable to address these issues.In this study,a plate-to-layer Bi2MoO6/Ti3C2Tx(MXene)heterostructure is proposed by electrostatic assembling positive-charged Bi2MoO6 nanoplates on negative-charged MXene nanosheets.MXene nanosheets in the heterostructure act as a highly conductive substrate to load and anchor the Bi2MoO6 nanoplates,so as to improve electronic conductivity and structural stability.When the mass ratio of MXene is optimized to 30%,the Bi2MoO6/MXene heterostructure exhibits high specific capacities of 692 mAh g?1 at 100 mA g?1 after 200 cycles and 545.1 mAh g?1 with 99.6%coulombic efficiency at 1 A g?1 after 1000 cycles.The results provide not only a highperformance lithium storage material,but also an effective strategy that could address the intrinsic issues of various transition metal oxides by anchoring them on MXene nanosheets to form heterostructures and use as anode materials for LIBs.

In-situ anion exchange based Bi_(2)S_(3)/OV-Bi_(2)MoO_(6)heterostructure for efficient ammonia production:A synchronized approach to strengthen NRR and OER reactions

Photocatalytic ammonia generation via nitrogen reduction reaction(NRR)is a green and prospective nitrogen fixation technique.However,NRR is often hampered by the high N_(2) adsorption/activation energies and is accompanied by a slow kinetics oxygen evolution reaction(OER).Herein,a robust Bi_(2)S_(3)/OVBi_(2)MoO_(6)S-scheme heterojunction is constructed using a simple in-situ anion exchange process,which enables oxygen vacancy(OVs)abundant Bi_(2)Mo O_(6) microspheres with surface deposited Bi_(2)S_(3).The asfabricated Bi_(2)S_(3)/OVBi_(2)MoO_(6) functioned as an effective photocatalyst to convert N_(2)-to-NH_(3) under mild conditions.The photocatalytic NH_(3)/NH_(4)^(+) production rate reached 126μmol g_(cat)^(-1)under visible light for2.5 h with 2%of Bi_(2)S_(3)/OVBi_(2)MoO_(6)photocatalyst,which was 8-fold higher than pristine Bi_(2)MoO_(6).Furthermore,the as-fabricated Bi_(2)S_(3)/Bi_(2)MoO_(6)heterojunction exhibited good selectivity,high stability and reproducibility.The excellent photocatalytic NRR performance was ascribed to the Bi_(2)S_(3)/Bi_(2)MoO_(6)heterojunction formed subsequent to the strong interaction between Bi_(2)S_(3)and Bi_(2)MoO_(6).The OVs facilitated the chemical adsorption process allowing activation of N_(2)molecule on the Bi_(2)S_(3)/Bi_(2)MoO_(6).Simultaneously,the S-scheme heterojunction prolonged the lifetime of photogenerated carriers,accelerated the electrons/holes spatial separation and accumulation on the Bi_(2)S_(3)(reduction)and Bi_(2)MoO_(6)side(oxidation),respectively,thus strengthening both OER and NRR half-reactions.This simple in-situ anion exchange method offers a novel technique for strengthening OER and NRR half-reactions in Bi-based photocatalysts for effective photocatalytic ammonia generation.

Selenium vacancies regulate d-band centers in Ni_(3)Se_(4)toward paired electrolysis in anion-exchange membrane electrolyzers for upgrading N-containing compounds

Paired electrolysis in anion-exchange membrane(AEM)electrolyzers toward the cathodic nitrate reduction reaction(NO_(3)RR)and anodic benzylamine oxidation reaction(BOR)could generate high value-added N-containing compounds simultaneously.The key challenge is to develop bifunctional electrocatalysts with a wide potential window,which can achieve highly efficient conversion of anode and cathode reactants.Herein,Ni_(3)Se_(4)with Se vacancies was prepared and employed as the cathode and anode of AEM electrolyzers for NO_(3)RR and BOR.^(15)N isotope-labeling online differential electrochemical mass spectrometry(DEMS)proved that ammonium was reduced from nitrates and revealed the reaction pathway of NO_(3)RR.The density functional theory calculation clarified that Se vacancies regulate d-band centers,and then further modulate the adsorption energy of adsorbed hydrogen,NO_(3)^(-)and intermediates on the Ni_(3)Se_(4)-60s surface in NO_(3)RR,so as to optimize the hydrogenation of NO_(3)^(-)into ammonia.Moreover,during the BOR,the Se vacancy can promote the adsorption of OH^(-),which is easier to form the active species of Ni OOH.The technical and economic evaluation exhibited that the cost of paired electrolysis is 1.21 times lower and the profit is 1.42 times higher than that of the unpaired electrolysis,which shows the economic attraction of paired electrolysis.This work delivers the guidance for the design of efficient catalysts for paired electrolysis in AEM electrolyzer toward the sustainable synthesis of value-added chemicals.

Impact of Water Molecules on the Isomerization of CH3S（OH）CH2 to CH3S（O）CH3： A Computational Investigation

The isomerization of CH3S（OH）CH2 to CH3S（O）CH3 in the absence and presence of water has been investigated at the G3XMP2//B3LYP/6-311 ＋ G（2df, p） level. The naked isomerization, the reaction without water, gives the high barrier height （21.56 kcal.mol^-1）. Three models are constructed to describe the water influence on the isomerization, that is, water molecules are the catalyst and the microsolvation, and water molecules act as the catalyst and microsolvation simultaneously. Our results show that the isomerization barrier heights of CH3S（OH）CH2 to CH3S（O）CH3 are reduced by 12.32, 11.04, and 7.80 kcal.mol^-1, respectively, when one, two, and three water molecules are performed as catalyst, in contrast to the naked isomerization. Moreover, the rate constants of the isomerization are calculated using the transition state theory with the Wigner tunneling correction over the temperature range of 240-425 K. We find that the rate constant of a single water molecule as the catalyst is 1.58 times larger than the naked isomerization at 325 K, whereas it is slower by 6 orders of magnitude when water molecule serves as the microsolvation at 325 K, compared to naked reaction. So the water-catalyzed isomerization of CH3S（OH）CH2 to CH3S（O）CH3 is predicted to be the key role in lowering the activation energy. The isomerization involving water molecules acting as mierosolvation is unfavorable under atmospheric conditions.