Modulating Hydrogen Adsorption via Charge Transfer at the Semiconductor–Metal Heterointerface for Highly Efficient Hydrogen Evolution Catalysis

Abstract

operable under a wide range of pH environments for the industrialization and commercialization of electrocatalytic H 2 production. Hydrogen binding energy (HBE) is a key parameter for evaluating the intrinsic activity of hydrogen evolution reaction (HER) electrocatalysts. [3] The intrinsic HER activity is determined by the electronic structure of the catalyst. [4] However, when the proton donor changes during the reaction because of the increasing electrolyte pH-H 3 O + in acidic and H 2 O in neutral/ alkaline media-the adsorption/desorption of interfacial water becomes an additional factor that influences the intrinsic HER activity. Therefore, to achieve optimal HER activity, the electronic structure of the electrocatalysts must be optimized. [5] Among the different strategies reported for tuning the electronic structure of these electrocatalysts, [6] interfacial engineering is the most effective. In this strategy, charge redistribution is induced by the electronic interaction across a heterostructure interface, which tunes the adsorption strength of reaction intermediates. [7] However, the monotonic transport pathway of the interfacial electrons in most heterostructure catalysts limits the simultaneous modulation of the catalyst electronic structure for optimal HBE and water dissociation kinetics at the electrocatalytic sites for HER (particularly in neutral and alkaline media). [8] Designing and synthesizing highly efficient and stable electrocatalysts for hydrogen evolution reaction (HER) is important for realizing the hydrogen economy. Tuning the electronic structure of the electrocatalysts is essential to achieve optimal HER activity, and interfacial engineering is an effective strategy to induce electron transfer in a heterostructure interface to optimize HER kinetics. In this study, ultrafine RhP 2 /Rh nanoparticles are synthesized with a well-defined semiconductor-metal heterointerface embedded in N,P co-doped graphene (RhP 2 /Rh@NPG) via a one-step pyrolysis. RhP 2 /Rh@NPG exhibits outstanding HER performances under all pH conditions. Electrochemical characterization and first principles density functional theory calculations reveal that the RhP 2 /Rh heterointerface induces electron transfer from metallic Rh to semiconductive RhP 2 , which increases the electron density on the Rh atoms in RhP 2 and weakens the hydrogen adsorption on RhP 2 , thereby accelerating the HER kinetics. Moreover, the interfacial electron transfer activates the dual-site synergistic effect of Rh and P of RhP 2 in neutral and alkaline environments, thereby promoting reorganization of interfacial water molecules for faster HER kinetics.

Electronic Structure Engineering of Pt Species over Pt/WO3 toward Highly Efficient Electrocatalytic Hydrogen Evolution

“…According to the d-band center theory, the downshift of d-band center usually leads to more high-energy antibonding states of hydrogen below the Fermi level, and hence weakens the H * adsorption, promoting the HER process (Figure 6e). [28,47,50,51] Generally, the free energy of hydrogen adsorption ( H* G ∆ ) has been widely known to be a key descriptor for HER activity. [52] And, a…”

Interface engineering of porous Co(OH)2/La(OH)3@Cu nanowire heterostructures for high efficiency hydrogen evolution and overall water splitting

“…6D and E). The changes in the electronic structure of Co could induce the electron rearrangement of the adjacent O atom in CH/LH@Cu NW-2, 57–60 which is proved by the shift of O 1s peaks in heterostructures (Fig. S20†).…”

Constructing abundant interfaces by decorating MoP quantum dots on CoP nanowires to induce electronic structure modulation for enhanced hydrogen evolution reaction

“…The enhanced HER performance can be mainly attributed to the introduction of MoP quantum dots and the modification of the electronic structure of the active sites at the interface, which could result in the optimal adsorption free energy of H* and energy barriers for H 2 O dissociation in the HER. 47,48…”