Search

• Superior peroxidase mimetic performance towards H 2 O 2 is founded in the typical Weyl semimetal WTe 2 , which is derived from the two-step electron pathway. • The robust topological surface states (TSSs) on WTe 2 which serve as effective electron bath are directly involved in the electron transfer process during the enzyme-like reaction. • The TSSs can efficiently deliver electrons and thus tune the peroxidase-like activity of WTe 2 , leading to faster reaction kinectics. [Display omitted] Nanozymes, as promising alternatives that integrate the advantage of natural enzymes and nanomaterials are attracted enormous interest due to their low cost, environmental tolerance, high stability, as well as significant catalytic activity. Two-dimensional materials, transition metal dichalcogenides (TMDs) harbor the potential as peroxidase mimic which is attributed to the active edge sites and surface electron transfer capability. However, a challenge faced in peroxidase mimetic of TMDs is the low catalytic activity which originates from the inert structures. Here, we, for the first time, report that the typical Weyl semimetal WTe 2 possesses the superior peroxidase-like performance toward H 2 O 2 , which derives from the two-step electron-pathway. We demonstrate a novel functionality of the Weyl semimetal through introducing topologically protected surface states (TSSs) for regulating the electron transfer processes. The underlying mechanism for TSSs promoting enzyme mimetic catalysis is attributed to the effective electron bath provided by the robust TSSs. Experiments and the first-principles calculations show that TSSs of WTe 2 which serve as effective electron baths are directly involved in the two-step electron transfer process. In the first step, TSSs accept the electrons donated by the substrate which further enhances the substrate's absorption. Upon H 2 O 2 adsorption, the electrons are transferred out of TSSs and injected into the absorbed H 2 O 2 orbitals. These findings offer a new linkage between the topological matters with TSSs and nanomaterials for enzyme mimicking. [ABSTRACT FROM AUTHOR]

• Curvature-dependent thermal expansion coefficients of carbyne nanostructures are obtained. • The thermal expansion of single bond is larger than that of triple bond and positive TECs are obtained. • The carbyne ring transform into a quasi-circle at high temperature. Carbyne nanostructures, including carbyne chain and carbyne ring, have been triggered substantial research due to their exotic mechanical and outstanding electronic properties. In order to clarify the bond nature of carbyne nanostructures under thermal environment, the thermal properties of single and triple bonds modulated by length and curvature effects are investigated based on the density functional theory (DFT) and atomic-bond-relaxation (ABR) correlation mechanism. We find that the discrepancies of elastic and thermal properties between single and triple bonds are determined by the difference of thermal expansion coefficients (TECs). Moreover, the length and curvature effects play a significant role on the TECs of carbyne nanostructures. Our results are consistent with the numerical simulations, illustrating the underlying mechanism on the thermal properties of carbyne nanostructures at the atomic-level. [ABSTRACT FROM AUTHOR]