The Application Of Defect Modified Transition Metal Nanomaterials In New Energy Conversion

With the wide application of nanomaterials in various fields,the physical and chemical properties of nanomaterials are facing more severe tests.The physical and chemical properties of nanomaterials largely depend on their intrinsic physical and chemical properties.Defect modification controls the physical and chemical properties of nanomaterials by adjusting the local surface structure and surface electronic structure of nanomaterials.Oxygen vacancies and doping are effective methods to introduce defect modification into nanomaterials,and are effective control strategies to control the physical and chemical properties of nanomaterials.Laser ablation in liquid are used to synthesize L-TiO₂ nanomaterials with oxygen vacancy.The defect modification strategy by introducing oxygen vacancies can control solar water evaporation rate and efficiency of the L-TiO₂ water evaporator.The defect modification strategy by introducing oxygen vacancies can adjust the band gap narrowing of L-TiO₂ nanomaterials,and then more incident photons can be absorbed to participate in the photothermal process,which greatly improved the light absorption and light-to-heat conversion capabilities of L-TiO₂ nanomaterials.Compared with TiO₂ nanomaterials,the water evaporation rate of the solar water evaporator assembled by the defect-modified TiO₂nanomaterials with oxygen vacancies was controlled at 1.25 kg m^-2 h^-1 in the solar water evaporation test,and the water evaporation efficiency in sunlight was controlled at 78.5%,both 1.8 times higher than TiO₂ nanomaterials.Self-sacrifice Template-directed by hydrothermal are uesd to synthesize NiFe-LDHs nanomaterials with Fe²⁺-doped.The defect modification strategy by introducing Fe²⁺doping could control the local surface structure of NiFe-LDHs nanomaterials,and introduce Fe²⁺-O-Fe³⁺bridge bonds structure,which could activate the inert plane and improve the specific surface area of the active edge.It can also control the surface electronic structure of nickel iron hydrotalcite,promote electron transfer,and improve conductivity.The Fe²⁺-doped NiFe-LDHs electrocatalyst shows excellent catalytic performance for oxygen evolution reaction.The Fe²⁺-doped NiFe-LDHs nanomaterials only need a low overpotential of 190m V to control the current density of 10 m A cm^-2in 1M KOH,and achieve a Tafel slope as low as 40.23 m V dec^-1,which is superior to the NiFe-LDHs nanomaterials.