Superior peroxidase mimetic activity induced by topological surface states of Weyl semimetal WTe2

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 WTe2 possesses the superior peroxidase-like performance toward H2O2, 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 WTe2 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 H2O2 adsorption, the electrons are transferred out of TSSs and injected into the absorbed H2O2 orbitals. These findings offer a new linkage between the topological matters with TSSs and nanomaterials for enzyme mimicking.