Recently, Prof. Chen Guangliang from the Department of Materials Science and Engineering, School of Engineering, Huzhou university published a paper entitled “Yttrium‐ and nitrogen‐doped NiCo phosphide nanosheets for high‐efficiency water electrolysis” in “Carbon-Energy” (TOP Q1 Chinese Academy of Sciences, IF: 20.5). This journal is internationally renowned in the field of materials science. The paper was published with Prof. Chen Guangliang as the first and corresponding author and with Huzhou University as the first unit.

　　Hydrogen energy has received increasing attention in the past decades. Hydrogen energy is considered to be the most promising energy carrier due to its high calorific value, zero pollution and high efficiency in its application. Currently, electrolytic water decomposition using renewable energy sources is considered as one of the most efficient methods for clean energy conversion and storage, which can provide high-purity hydrogen (H2) for hydrogen fuel cells, laboratories and chemical synthesis. The main challenge in electrocatalytic water decomposition lies in the design of efficient electrocatalysts for the reduction of high overpotentials in the oxygen-extraction reaction (OER) and hydrogen-extraction reaction (HER), which can speed up the reaction rate and reduce energy consumption. Although precious metal platinum (Pt)- and ruthenium/iridium (Ru/Ir)-based catalysts are still the most efficient electrocatalysts respectively for HER and OER, their scarcity and high cost greatly limit their commercial applications. Therefore, the design of abundant, low-cost, efficient and stable non-precious-metal electrocatalysts is crucial for the development of H2 energy sources.

　　To address the above challenges, Prof. Chen Guangliang’s team initiated a new method to improve the electrocatalytic activity and stability under alkaline electrolytic conditions by using a trace amount of yttrium (Y), a rare earth metal, and plasma treatment. This method first modifies nickel-cobalt alloy foam (NCF) by dielectric barrier discharge (DBD) plasma to form microscopic nanodefects on the NCF surface; then smooth yttria-doped nickel-cobalt layered double hydroxide nanosheets (YNiCo LDH/PNCF) are hydrothermally grown on the surface of plasma-treated NCF (PNCF) in-situ; and finally, the plasma treatment is carried out using radio-frequency in nitrogen gas. The plasma was phosphatized to obtain yttrium- and nitrogen-doped phosphatized nickel-cobalt nanoflake electrocatalysts (N-YNiCoP/PNCF). The obtained N-YNiCoP/PNCF has a large specific surface area, abundant heterogeneous interfaces and optimized electronic structure, and exhibits high electrocatalytic activity in HER (331 mV vs. 2000 mA cm-2) and OER (464 mV vs. 2000 mA cm-2) reactions in 1 M KOH electrolyte. X-ray absorption spectroscopy (XAS) and DFT Quantum chemical calculations show that the coordination number of CoNi decreases with the addition of Y atoms, resulting in shorter bonds between Ni and Co ions, achieving long runtime stability of N-YNiCoP in HER and OER reactions under simulated industrial conditions. Meanwhile, the CoN-YP5 hetero-surface formed by plasma N doping is the active center of the whole water splitting. This work expands the application of rare earth elements in bifunctional electrocatalysts and opens a new direction for designing high-performance transition metal-based catalysts in the field of renewable energy.

　　Paper link：https://doi.org/10.1002/cey2.522

　　Correspondent：Zhang Qun