Coexistence of Zero-Dimensional Electride State and Superconductivity in AlH_(2)Monolayer

Elect rides,which confine"excess anionic electrons"in subnanometer-sized cavities of a lattice,are exotic ionic crystals.We propose a non-stoichiometric strategy to realize intrinsic two-dimensional(2D)superconducting elect ride.AlH_(2)monolayer,which is structurally identical to 1H-MoS_(2),possesses zero-dimensionally confined anionic electrons in the interstitial sites of A1 triangles,corresponding to a chemical formula of[AlH_(2)]^(+)e^(-).The interaction between interstitial anionic electrons(IAEs)and host cation lattice mainly accounts for stabilization of 1H-AlH_(2)electride.Impressively,1H-AlH_(2)monolayer is an intrinsic Bardeen-Cooper-Schrieffer superconductor with T_(c)=38 K,which is the direct consequence of strong coupling of the H-dominated high electronic states with Al acoustic branch vibrations and mid-frequency H-derived phonon softening modes caused by Kohn anomalies.Under tensile strain,IAEs transform into itinerant electrons,favoring the formation of stable Cooper pairs.Therefore,T_(c)reaches up to 53 K at a biaxial fracture strain of 5%.Our findings provide valuable insights into the correlation between non-stoichiometric electrides and superconducting microscopic mechanisms at the 2D limit.

Polyvinylpyrrolidone as an Efficient Stabilizer for Silver Nanoparticles

Aggregation of nanoparticles is a serious problem in their applications.In this article,stability of biosynthesized silver nanoparticles(AgNPs)was initially studied with different concentrations of sodium chloride(NaCl).Surfactant screening showed that polyvinylpyrrolidone(PVP)was an ideal stabilizer,which not only was effective at a low concentration(0.1%,V/V),but also could protect silver colloids from aggregation for a long period at 1 mol•L^(−1) NaCl,and 6 h even at 3 mol•L^(−1) NaCl.However,some other surfactants,such as sodium dodecyl(SDS),Triton X-100,Tween-20,and Tween-80,could not prevent AgNPs from aggregation even at a high concentration up to 0.5%(V/V).This AgNPs stabilizer is simple and convenient for a variety of applications compared with others.