Construction of hierarchical FeP/Ni2P hollow nanospindles for efficient oxygen evolution

• Published in: Journal of materials chemistry. A, Materials for energy and sustainability Materials for energy and sustainability, 2018, Vol.6 (29), p.14103-14111
• Main Authors: Feng, Yafei, Xu, Chunyang, Hu, Enlai, Xia, Binbin, Ning, Jiqiang, Zheng, Changcheng, Zhong, Yijun, Zhang, Ziyang, Hu, Yong
• Format: Article
• Language: English
• Subjects: Chemical synthesis; Composite materials; Construction; Morphology; Nickel; Oxygen; Oxygen evolution reactions; Phosphating (coating); Reagents; Silicon dioxide; Spindles; Structural hierarchy
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/c8ta03933j

In this work, we demonstrate the design and construction of hierarchical FeP/Ni2P hybrid hollow nanospindles (HNSs) as an active and stable electrocatalyst for the oxygen evolution reaction (OER). Employing solid FeOOH NSs coated with a thin layer of SiO2 as the template and Ni(NO3)2·6H2O as the reagent, 2D nickel silicate (Ni3Si4O10(OH)2·5H2O) nanosheets were grown on the surface of the FeOOH spindles through a facile solvothermal method to produce hierarchical FeOOH@Ni3Si4O10(OH)2·5H2O hybrid NSs. Following a subsequent phosphorization treatment, the as-prepared solid composite NSs were successfully converted into FeP/Ni2P HNSs. The SiO2 nanocoating was found to play a crucial role in this synthesis, and served not only as a reagent for the solvothermal reaction, but also as a nanoreactor for preserving the template morphology after the phosphorization treatment. Benefiting from the unique hollow and hierarchical nanoscaled hybrid structure, the FeP/Ni2P HNS electrocatalyst displays superior electrocatalytic activity for the OER to FexP, Ni2P and the physical mixture of FexP and Ni2P samples, achieving an overpotential of 234 mV at a current density of 10 mA cm−2 in 1 M KOH and a relatively low Tafel slope of 56 mV dec−1.