| With the consumption of traditional fossil energy and environmental pollution,the search for alternative clean energy has been widely concerned.Solar energy is an inexhaustible renewable clean energy,which will not produce any environmental pollution in the process of use.Photosynthesis plays an important role on the earth.Light induced organic reactions have artificially created many valuable substances.Some researchers have also synthesized precious metal nanoparticles and inorganic salts by direct or indirect photoreduction process.However,there are few reports on photo-assisted synthesis of inorganic compounds.At the same time,with the emphasis on space exploration,the development of medical physics and the increasing difficulty of resource exploration on the earth,it is necessary to develop a kind of power system that can provide its own energy without care.In addition,the process of human production and life will inevitably produce waste heat,especially factory waste heat,which causes thermal pollution to our living environment.It is necessary to develop some materials and equipments to make full use of the waste heat.Thermoelectric power generation is particularly suitable for these applications.This project mainly includes the following aspects:1.The photo-assisted synthesis of inorganic mixed valence polyvanadates[C9H14N]6[V15O36Cl]was investigated.The formation kinetics and crystal growth kinetics process of polyvanadates under light irradiation were revealed.Single-crystal X-ray diffraction analysis reveals[C9H14N]6[V15O36Cl]is hexagonal(space group P63/mmc)with cell parameters:a=b=14.1100(6)A,c=22.0265(10)A,and V=3797.8(4)A3.When the When the simulated solar light intensity is 200 mW·cm-2,the crystal growth process is determined to be rapid cage formation,slow nucleation and final crystal growth by analyzing the samples under different light time.Ultraviolet-visible spectroscopy and Electron Paramagnetic Resonance analyses verified that the[V15O36Cl]6-cluster formed within 0.5 h;Powder X-ray diffraction results indicated that the crystalline phase appeared after irradiation for 9.5 h.These findings suggested that the nucleation and crystallization processes took longer than[V15O36Cl]6-cluster formation and dominated the[C9H14N]6[V15O36Cl]crystal formation.This primary work could open the door for the syntheses of inorganic compounds using photo-assisted reactions instead of conventional thermo-driving syntheses.2.A thermoelectric composite PANI-NiV14 was synthesized in situ method.The conductive porous polyaniline(PANI)acidified by phytic acid has different properties from the traditional organic thermoelectric materials,that is,the conductivity increases while the thermal conductivity basically remains unchanged,so it is a very potential thermoelectric material.A new polyvanadates[V14O34Ni(Phen)3Cl2](NiV14)with semiconductor properties can not only be used as a semiconductor material to produce carriers,but also has redox ability because it contains an electrically neutral cage[VⅤ2VⅣ2O34]cluster with V4+/V5+.However,as an inorganic compound,NiV14 has poor conductivity.So we combined the advantages of PANI and NiV14 by in-situ synthesis.The introduction of NiV14 redox material with semiconductor properties into PANI system can produce more carriers due to the existence of temperature difference between cold and hot Besides,some of the carriers that may be quenched due to the defects of π-π conjugate chain in PANI will be redox reacted with NiV14 to re export the carriers,so that the carrier concentration will not decrease,which promotes the improvement of thermoelectric properties,and provides a new idea for the development of new organic thermoelectric materials. |
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