Superconducting properties and topological nodal lines features in centrosymmetric Sn_(0.5)TaSe_(2)

Nontrivial topological behaviors in superconducting materials provide resourceful ground for the emergence and study of unconventional quantum states.Charge doping by the controlled intercalation of donor atoms is an efficient route for enhancing/inducement of superconducting and topological behaviors in layered topological insulators and semimetals.Herein,we enhanced the superconducting temperature of TaSe_(2) by 20-folds(~3 K)through Sn atoms intercalation.Using first-principles calculations,we demonstrated the existence of nontrivial topological features.Sn_(0.5)TaSe_(2) displays topological nodal lines around the K high symmetry point in the Brillouin zone,with drumhead-like shaped surface states protected by inversion symmetry.Altogether,the coexistence of these properties makes Sn_(0.5)TaSe_(2) a potential candidate for topological superconductivity.

Activating ruthenium dioxide via compressive strain achieving efficient multifunctional electrocatalysis for Zn-air batteries and overall water splitting

Surface strain engineering is a promising strategy to design various electrocatalysts for sustainable energy storage and conversion.However,achieving the multifunctional activity of the catalyst via the adjustment of strain engineering remains a major challenge.Herein,an excellent trifunctional electrocatalyst(Ru/RuO_(2)@NCS)is prepared by anchoring lattice mismatch strained core/shell Ru/RuO_(2)nanocrystals on nitrogen-doped carbon nanosheets.Core/shell Ru/RuO_(2)nanocrystals with~5 atomic layers of RuO_(2)shells eliminate the ligand effect and produce~2%of the surface compressive strain,which can boost the trifunctional activity(oxygen evolution reaction[OER],oxygen reduction reaction[ORR],and hydrogen evolution reaction[HER])of the catalyst.When equipped in rechargeable Zn-air batteries,the Ru/RuO_(2)@NCS endows them with high power(137.1 mW cm^(2))and energy(714.9 Wh kg_(Zn)^(-1))density and excellent cycle stability.Moreover,the as-fabricated Zn-air batteries can drive a water splitting electrolyzer assembled with Ru/RuO_(2)@NCS and achieve a current density of 10 mA cm^(2)only requires a low potential~1.51 V.Density functional theory calculations reveal that the compressive strained RuO_(2)could reduce the reaction barrier and improve the binding of rate-determining intermediates(*OH,*O,*OOH,and*H),leading to the enhanced catalytic activity and stability.This work can provide a novel avenue for the rational design of multifunctional catalysts in future clean energy fields.

Defect-rich ultrathin poly-heptazine-imide-framework nanosheets with alkali-ion doping for photocatalytic solar hydrogen and selective benzylamine oxidation

Polymeric carbon nitride(CN)as a metal-free photocatalyst holds great promise to produce high-value chemicals and H_(2) fuel utilizing clean solar energy.However,the wider deployment of pristine CN is critically hampered by the poor charge carrier transport and high recombination.Herein,we develop a facile salt template-assisted interfacial polymerization strategy that insitu introduces alkali ions(Na+,K+)and nitrogen defects in CN(denoted as v-CN-KNa)to simultaneously promote charge separation and transportation and steer photoexcited holes and electrons to their oxidation and reduction sites.The photocatalyst exhibits an impressive photocatalytic H_(2) evolution rate of 8641.5μmol·g^(−1)·h^(−1)(33-fold higher than pristine CN)and also works readily in real seawater(10752.0μmol·g^(−1)·h^(−1))with a high apparent quantum efficiency up to 18.5%at 420 nm.In addition,we further demonstrate that the v-CN-KNa can simultaneously produce H_(2) and N-benzylidenebenzylamine without using any other sacrificial reagent.In situ characterizations and DFT calculations reveal that the alkali ions notably promote charge transport,while the nitrogen defects generate abundant edge active sites,which further contribute to efficient electron excitation to trigger photoredox reactions.

Charge density wave phase suppression in 1T-TiSe_(2) through Sn intercalation

Taking advantage of the unique layered structure of TiSe2,the intrinsic electronic properties of two-dimensional materials can easily be tuned via heteroatomic engineering.Herein,we show that the charge density wave(CDW)phase in 1T-TiSe_(2) single-crystals can be gradually suppressed through Sn atoms intercalation.Using angle-resolved photoemission spectroscopy(ARPES)and temperature-dependent resistivity measurements,this work reveals that Sn atoms can induce charge doping and modulate the intrinsic electronic properties in the host 1T-TiSe_(2).Notably,our temperature-dependent ARPES results highlight the role exciton-phonon interaction and the Jahn-Teller mechanism through the formation of backfolded bands and exhibition of a downward Se shift of 4p valence band in the formation of CDW in this material.