MoS2/NiVFe crystalline/amorphous heterostructure induced electronic modulation for efficient neutral-alkaline hydrogen evolution. (1st January 2023)

• Record Type: Journal Article
• Authors: Li, Jianxiong; Du, Xiaohang; Luo, Yuhong; Han, Binbin; Liu, Guihua; Li, Jingde
• Is Part Of: Electrochimica acta. Volume 437(2023)
• Publication Date: 2023-01-01
• Subjects: Crystalline-amorphous heterostructure -- Molybdenum sulfide -- Electronic modulation -- Neutral and alkaline media -- Hydrogen evolution reaction; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2022.141478
• Languages: English
• ISSNs: 0013-4686

Abstract

Highlights: Crystalline-amorphous MoS2 /NiVFe is developed as efficient HER electrocatalyst. MoS2 /NiVFe has enhanced electrochemically active surface area and active sites. Electronic modulation in MoS2 /NiVFe leads to high-valent Ni and electron-rich S. High-valent Ni and electron-rich S attract OH and H in H2 O to avail its splitting. MoS2 /NiVFe delivers superior HER activity in alkaline and neutral medium. Abstract: MoS2 is attractive for electrocatalytic hydrogen evolution reaction (HER) as an inexpensive transition metal-based electrocatalyst, however, its catalytic performance within a wide pH range is still challenging. Herein, NiVFe layered double hydroxide (LDH) modified MoS2 (MoS2 /NiVFe) is developed by a two-step hydrothermal method to form a crystal-amorphous heterostrctural electrocatalyst. The crystal-amorphous heterostrcture is demonstrated to provide a large electrochemically active surface area to enhance the active sites and expedite the electron transfer. More importantly, a strong electronic modulation effect is revealed by XPS and theoretical calculations that electrons in NiVFe-LDH transfer to MoS2, which results in high-valent Ni-site to attract -OH and electron-rich S-site to adsorb -H, significantly reducing the barriers of water splitting. As a result, at 10 mA cm −2 in alkaline and neutral media, the MoS2 /NiVFe electrocatalyst exhibits low overpotentials for HER of 78 and 141 mV, respectively. A remarkable activity towards OER is also achieved accompanied with an impressive stability. When applied as both electrodes for overall water separation, it only needs a low cell voltage of 1.47 V for MoS2 /NiVFe to provide a current density of 10 mA cm −2 in 1.0 M KOH. This study provides an efficient method for designing MoS2 -based electrocatalysts for HER within a broad pH range. Graphical abstract: A crystalline-amorphous MoS2 /NiVFe heterostructure electrocatalyst was prepared by a two-step hydrothermal method. Electronic modulation exists in the MoS2 /NiVFe heterointerface, leading to high-valent Ni and electron-rich S sites, which can facilitate the adsorption of OH and H in H2 O to avail water splitting. Excellent HER performance is obtained in both alkaline and neutral media. Image, graphical abstract