Morphology Of Titanium Nitride Synthesis And Photolysis Aquatic Hydrogen Performance Study

The research of titanium nitride in catalysis and materials exhibits very importantvalue for theory and potential applications. It should be pointed out that titaniumnitride can be utilized as the substitution for noble metal Pt in the catalytichydrogenation owing to its special properties similar to the latter. Thus, metal nitridehas become an important semiconductor for the research of catalysis and materials.Nevertheless, such semiconductor materials have not been explored as an excellentfunctional materials for storage and transfer energy because of the complicatedsynthesis craft, low surface area, poor micro/nano architectures, and so on.In order to solve the proposed problems in the synthesis and applicationprocess, this thesis focused on exploring novel route for fabricating series of titaniumnitride with special morphologies and enhanced catalytic performance based onmorphology-composition control. The structure-activity relationships for theas-obtained materials have been also investigated. This thesis mainly contains thefollowing three parts:1. In-situ carbothermal reduction and N2-nitridation strategy to mesoporoustitanium nitride spheres with tunable chamber structures for photocatalytic hydrogenevolutionThe precursors of titanium nitride with controllable morphologies were preparedvia a solvothermal method (solid structure, core-shell structure, hollow-shellstructure). The as-obtained titanium nitrides were further nitrided in nitrogen uponhigh temperature treatment. The effect of the morphologies, compositions andphysicochemical properties on the as-prepared titanium nitride have been deeplydiscussed based on the characterizations, including XRD, FESEM, TEM, DRS, BETand so on. In anditon, the titanium nitride photocatalysts with controllablemorphologies could be utilized as photocatalysts for water splitting for hydrogenevolution under visible light irradiation. Meanwhile, we also proposed the conceptabout in-situ carbothermal reduction and N2-nitridation strategy and put emphasis onthe effect of the different sacrificial ragent played and even the photocatalytic machanism in the process of water splitting. Last, these titanium nitride photocatalystswith controllable morphology exhibited high catalytic activity in photocatalyticreaction under the Na2S-Na2SO3buffer system.2. Solvothermal synthesis of nitride titanium photocatalyst with controllablemorphology nanostrctures in NH3and its photocatalytic hydrogen evolutionproperties.As the described above, the precursors of titanium nitride with controllablemorphologies were also prepared via solvothermal method (solid structure, core-shellstructure, hollow-shell structure). Then the precursors of titanium nitride were furthernitrided in ammonia atmosphere. The effect of the morphologies, compositions andphysicochemical properties on the as-prepared titanium nitride have been deeplydiscussed based on the results of XRD, FESEM, TEM, DRS, BET, PL and so on. Theas-prepared titanium nitride photocatalysts with controllable morphologies wereutilized as visible-light response photocatalysts for hydrogen evolution through watersplitting. The samples wholly copied the nanostructure of the precursors ownmesoporous structure and big BET. The effect of the existing carbon on thephotocatalytic activity and the influence between the structure and activity werestudied. Last, these titanium nitride photocatalysts with controllable morphologyexhibited higher catalytic activity in photocatalytic reaction and the core-shellstructure shows best activity under the Na2S-Na2SO3buffer system.3. Synthesis of titanium nitride coated carbon nanotubes photocatalyst and itsphotocatalytic hydrogen evolution from water splitting.The precursor of titanium dioxide supported on carbon nanotube were preparedvia solvothermal method. Then the titanium nitride coated carbon nanotubesphotocatalyst were obtained via a in-situ carbothermal reduction and nitridationstrategy involing ammonia as a nitrogen source. The titanium nitride nanoparticlewere well dispersed due to the presence of carbon nanotube.. The specific surface areaof the composite materials were greatly enhanced. The decreased recombination ratebetween electrons and holes leaded to better photocatalytic activities due to the highconductivities of carbon nanotubes. The effect of the morphologies, compositions and physicochemical properties of the as-prepared samples have been investigated basedon XRD, FESEM, TEM, DRS, BET ananlysis. The effect of the solvothermalcondition on the formation the composition material were sysmetically studies. Thesamples have big BET and higher activity in this part. Also the titanium nitride/carbonnanotube composite photocatalysts showed excellent visible-light drivenwater-spiltting capabilities under the Na2S-Na2SO3buffer system.