Modification,Fabrication And Synthesis Of Ni-Based Nanomaterials For Electrochemical Catalyst

With the unsaturated electronic on the d orbital,Nicke-based catalysts usually have an excellent capabilities of gaining and lossing electrons,which show good catalytic performance.Recently,owning to low cost,abundantly available source as well as lager active area,Ni nanoparticles have attracted more attention and show better electrocatalytic activity in enzyme-free glucose sensor and hydrogen evolution reaction.However,external introducing of Ni may lead to nonuniform distribution of the Ni NPs on the supporting materials because of self-agglomeration and grain growth.If the Ni NPs can precipitate from Ni containing nanoarrays,uniform Ni NPs immobilized nanoarrays will be easy to achieve.Such an uniform Ni NPs modified nanoarrays will be an excellent candidate for glucose sensors because that the in situ precipitated uniform Ni NPs not only can firmly anchor to the support nanoarrays resulting in high stability,but also offer one-dimensional nanostructures to transfer electrons.In this thesis,systematic studies on the synthesis,characterization and electrochemical properties of one-dimensional nanostructure arrays on Ti substrates with Ni-based materials have been presented.The main results are summarized as follows:（1）A novel non-enzymatic glucose biosensing platform consisting of highly ordered rhizobia-like nickel nanoparticles/titanium oxide nanowires composite arrays（Ni NPs/TiO₂ NWAs）.The Ni NPs/TiO₂ NWAs were fabricated via hydrothermal treatment of Ti foil in a NaOH solution,Ni ion exchange,and subsequent annealing under H₂/Ar.Theas-reduced Ni NPs were in situ grown on the surface of TiO₂ NWAs by the phase separation.The structure and electrochemical properties of the Ni NPs/TiO₂ NWAs have been systematically investigated.The results showed that the phase separation process made the nanoparticles anchor to the support nanoarrays with high stability.（2）A novel and simple strategy for the in situ fabrication of the microstructure composed of nickel（Ni）nanoparticles on nitrogen-doped TiO₂ nanowire arrays（Ni NPs/TiO_xN_y NWAs）by reduction in NH₃ is designed and described.The reshaped composite that is supported by the compact structure and interface of the formed NPs and remaining highly conductive TiO_xN_y NWAs forms a robust electrode in highly sensitiveand selective non-enzymatic glucose sensing.The materials exhibit outstanding electrocatalytic activity for glucose oxidation.In addition,compared with the commercial blood glucose meter contrast test,Ni NPs/TiO_xN_y NWAs showed a mere difference of 3.3%.The study provides a new insight into the development of new high-performance,low-impedance nano-catalyzed sensing electrodes.（3）A novel and simple strategy synthesized for the fabrication of the microstructure composed of Ni₂P NPs/TiO_xN_y NWAs composite nanometer arrays from Ni NPs/TiO_xN_y NWAs.The stability and durability of the Ni₂P NPs/TiO_xN_y NWAs electrode are excellent for electrocatalytic hydrogen evolution.The high catalytic activity of Ni₂P NPs/TiO_xN_y NWAs is attributed to the excellent performance of Ni₂P which facilitates electron transfer using the coordination interaction between phosphorus and transition metals and the highly conductive one-dimensional TiO_xN_y NWAs.The development of this electrocatalytic hydrogen production material provides a new solution for the development of new clean energy.