Facile Synthesis of Three‐dimensional Hierarchical Ni₃S₂@CoAl‐LDHs Nanosheet Arrays and Their Efficient Hydrogen Evolution

Abstract

Designing an electrocatalyst with optimized structure and performance is vital for the electrolysis of water to produce hydrogen. Herein, a three‐dimensional (3D) hierarchical composite electrode material is proposed for alkaline hydrogen evolution reaction (HER), consisting of Co−Al hydroxides (CoAl‐LDHs) nanosheets decorated with vertically aligned nickel sulfide (Ni3S2) arrays (Ni3S2@CoAl‐LDHs/NF). The as‐obtained electrocatalyst displays a minimum overpotential of 175 mV at 10 mA cm−2 toward HER. Electrochemical impedance spectroscopy and Tafel slope further reveals outstanding kinetics in the electrolysis process. The catalytic performance of the electrode can still maintain 90 % capacity after 1000 CV cycles. The outstanding properties of the composite material benefits from its unique 3D hierarchical structure, which promote plentiful active sites and faster electronic transfer rate. This work sheds lights on the current research of noble‐metal‐free electrocatalysts and the design of overall water splitting.

Synergistic Coupling of Hierarchical Heterostructured Ni3P/Ni/VN Microflower Electrocatalyst for Enhanced Hydrogen Evolution Reaction

“…Recently, more efforts have been devoted to develop transition metal-based HER electrocatalytic materials, including transition metal nitrides, [14] phosphides, [15][16][17] carbides, [18] sulfides [19] and oxygen/hydroxides. [20][21] Meanwhile, a variety of structural or electronic manipulation strategies have been deployed to enhance electrocatalytic activity, such as the construction of three-dimensional (3D) hierarchical structure, [4,22] heterojunction structure, [23] heteroatom doping, [24] defect engineering, [25] d-band modulation, [2,26] etc. In particular, the design of multicomponent integration catalysts (MICs) has aroused tremendous interest, which can utilize the coupling synergies generated by the individual component to achieve the adsorption/desorption equilibrium of hydrogen intermediates for HER process, thus accelerating the reaction kinetics.…”

“…Recently, more efforts have been devoted to develop transition metal‐based HER electrocatalytic materials, including transition metal nitrides, [14] phosphides, [15–17] carbides, [18] sulfides [19] and oxygen/hydroxides [20–21] . Meanwhile, a variety of structural or electronic manipulation strategies have been deployed to enhance electrocatalytic activity, such as the construction of three‐dimensional (3D) hierarchical structure, [4,22] heterojunction structure, [23] heteroatom doping, [24] defect engineering, [25] d‐band modulation, [2,26] etc.…”