Engineering Amorphous/Crystalline Rod-like Core–Shell Electrocatalysts for Overall Water Splitting

Abstract

The design of bifunctional electrocatalysts for hydrogen and oxygen evolution reactions delivering excellent catalytic activity and stability is highly desirable, yet challenged. Herein, we report an amorphous RuO2-encapsulated crystalline Ni0.85Se nanorod structure (termed as a/c-RuO2/Ni0.85Se) for enhanced HER and OER activities. The as-prepared a/c-RuO2/Ni0.85Se nanorods not only demonstrate splendid HER activity (58 mV@10 mA cm–2 vs RHE), OER activity (233 mV@10 mA cm–2 vs RHE), and electrolyzer activity (1.488 V@10 mA cm–2 vs RHE for overall water splitting) but also exhibit long-term stability with negligible performance decay after 50 h continuous test for overall water splitting. In addition, the variation of the d-band center (from the perspective of bonding and antibonding states) is unveiled theoretically by density functional theory calculations upon amorphous RuO2 layers coupling to clarify the increased hydrogen species adsorption for HER activity enhancement. This work represents a new pathway for the fabrication of bifunctional electrocatalysts toward green hydrogen generation.

Interface Engineering Induced Electron Redistribution at PtNs/NiTe‐Ns Interfaces for Promoting pH‐Universal and Chloride‐Tolerant Hydrogen Evolution Reaction

“…[32] To further verify the presence of oxygen vacancies, the electron paramagnetic resonance (EPR) measurements were performed, and a strong EPR signal was observed at g = 2.002 of Pt Ns /NiTe-Ns sample compared to bare NiTe-Ns (Figure 2e), indicating abundant oxygen vacancies in the Pt Ns /NiTe-Ns, consistent with XPS results. [28,33] Furthermore, the d-band centers of the as-prepared catalysts were tested by the surface valence band photoemission spectra measurements, which is closely related to the adsorption strength of HER intermediates. [21] As shown in Figure 2f, the d-band center values of Pt Ns /NiTe-Ns is -5.33 eV, which is slightly shifted toward the Fermi level compared to that of commercial Pt/C (-5.61 eV) but lower than that of NiTe-Ns (-5.13 eV).…”

A critical review on amorphous–crystalline heterostructured electrocatalysts for efficient water splitting

“…9a). 55 Density functional theory calculations of the coupling of amorphous RuO 2 layers revealed the modification of the d-band center (from the standpoint of bonding and antibonding states) to explain the enhanced hydrogen species adsorption for HER activity augmentation. As shown in Fig.…”

Order–disorder engineering of RuO2nanosheets towards pH-universal oxygen evolution

“…[19][20][21][22] Recently, phase engineering of Ru-based catalysts has gained considerable attention owing to their highly catalytic sites and chemical durability. [23][24][25][26][27] For instance, Yu et al 28 constructed oxygen-vacancy-rich RuO 2 nanosheets with disordered structures via a molten-salt strategy. Distinct from the crystalline counterpart, the amorphous phase enabled a rich body of randomly oriented and unsaturated coordination bonds, contributing to lowering down the O 2p band and increasing the covalency of the Ru-O bond, which thus results in an enhancement of electrocatalytic activity.…”