| With the needs of social development,the usage of resources at the earth is increasingly and for human beings,and the rate of consumption is getting faster and faster.But,the resources of the earth are limited,which ultimately leads to many problems such as global warming and environmental pollution.How to use sunlight rationally and make efficient and economical solar cells has become an effective means to solve this problem.As a commonly used material for solar cells,titanium dioxide(TiO2)nanomaterials have been widely researched in environmental purification,water treatment,exhaust gas purification,deodorization,weathering,anti-aging,automotive topcoats.Meanwhile,TiO2 can be used as a raw material for removing formaldehyde in photocatalyst products,and it has broad application prospects in the fields of information,materials,energy,environment,health and medical.However,because of the band gap(-3.0 eV)of titanium dioxide,it can only absorb the ultraviolet region of sunlight,which limits its better use of sunlight.Therefore,the relevant research groups have carried out a lot of researches on TiO2 composite materials.In this article,the main contents are as follows:1:Stable Bi2S3 quantum dots(QDs)prepared by a modified successive ionic layer adsorption and reaction(SILAR)method were used to decorate TiO2 nanorod(TNR)arrays and enhance their photoelectrochemical(PEC)performance.In the above procedure,the elemental sulfur vapor was utilized as a precursor instead of aqueous Na2S to prevent the photodecomposition of QDs,whereas the hydrolysis of the Bi precursor(Bi(NO3)3)was prevented by using 3-mercaptopropionic acid as a stabilizer.Interfacial charge recombination was inhibited by depositing ZnSe passivation layers.The morphological,structural,compositional,and optical/PEC property of the photoelectrodes were analyzed.The results showed that the ideal bandgap and high absorption coefficient of Bi2S3 QDs resulted in the enhanced visible light absorption and PEC performance of QD-sensitized TNR thin films,as compared to those of bare TNR films.The deposition of ZnSe on sensitized films leaded to the enhancement of PEC performance,achieving a photocurrent density of 0.11 mA/cm2 and an electron lifetime of 37.9ms,which was attributed to the effective suppression of charge carrier recombination by ZnSe passivation layers.Thus,the facile synthesis and environmentally-friendly nature of Bi2S3 QD-sensitized TNR films coated with ZnSe passivation layers make them promising components of solar energy driven devices.2:The novel TiO2 nanosheet(TNS)array films decorated with MoS2 nanosheets had been successfully prepared by a two-step hydrothermal method.The polycrystal TNS films constructed by compact nanosheets were first synthesized on FTO substrate,and a layer of MoS2 nanosheets was selectively loaded on the {101}surface of TNS.The structure,surface morphology,optical property,and photoelectrochemical properties of the MoS2/TNS films were investigated.It can be seen that the amount and coverage of MoS2 nanosheets on the TNS can be controlled by adjusting precursor concentration.The MoS2/TNS films exhibited stronger absorption in the visible light range and lower electron-hole recombination rate compared with pure TNS.In addition,the MoS2/TNS films exhibited the best photocurrent density(138 ?A/cm2),which was 21 times higher than that of bare TNS(6.4 ?A/cm2).The excellent photoelectrochemical property could be ascribed to the unique structure,extended light response and high-efficient separation of the photogenerated electron-hole pairs in MoS2/TNS films. |
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