Fabrication And Investigation Of Directly Grown FeP And Ni₃S₂ Nanostructures As The Electrodes For High-performance Water Splitting

Hydrogen is an efficient, clean, renewable and storable energy source, and has been widely investigated. The high price of hydrogen production is the main blockage for hydrogen as a popular fuel. Water splitting is a convenient way to produce hydrogen in a large scale. Noble metals such as Pt and Ir are currently used electrocatalysts for water splitting but they are scarcity and expensive. Thus, it is crytical to explore electrocatalysts with low price and high catalytic performance for hydrogen production. Extensive research has been conducted in this topics.This MS thesis reviews the the research history of water electrolysis on how to reduce the expense of water electrolysis and explores the catalytic mechanism of the noble metal in water electrolysis, in particular the enhancement mechanism of the electrocataysis toward hydrogen evolution reaction and oxygen evolution reaction. Herein, we investigate a directly grown metal compound nanostructures as an efficient electrode for water electrolysis demonstrating excellent electrocatalytic performance. The main achievements of this thesis project are as follows:1. We successfully obtained FeP nanorod arrays grown on HCl-treated Ti foil (FeP NAs/Ti) using a hydro-thermally treatment with FeCl3·6H2O and Na2SO4 as precursors, which is easy to control the product nanostructure and morphology. In the electrochemical characterization, FeP NAs/Ti is highly active toward the HER. In particular, the prepared electrocalalyst performance at high current densities is close to the commercial Pt. The mechanism for high performance is synergically contributed by high intrinsic electroactivity of FeP toward hydrogen evolution reaction, the direct integration of FeP NFs on HCl-treated Ti foil for good mechanical adhesion and electrical contact and fast electron transport along the nanorod. Furthermore, its 3D porous configuration allows easy diffusion of electrolyte and thus more efficient utilization of active sites in FeP NFs.2. We perform one-step electrodeposition of Ni3S2 nanoparticles on nickel foam (Ni3S2 NPs/NF) as an electrocatalyst toward oxygen evolution reaction (OER). It is a facile way to fabricate the electrocatalyst on the nickel foam. Compared with the bare nickel foam, Ni3S2 nanoparticles grown on nickel foam has lower onset overpoential. At the same potential, the electrocatalyst has larger current density. An OER during long term operation behavior suggests that the Ni3S2/NF electrode exhibits good durability for OER in 0.1 M KOH.