The Fabrication And Application Of Ternary Chalcogenide Compounds And PPy-PANI/TiO₂

Organic pollutants have great effects on the human and animal health.Phenols and other organic matter are often detected in our drinking water,and when the accumulation of phenols or other harmful organic matter in animal body to a certain amount will cause a series of disease.Scientists have developed many methods to remove the harmful substances from water,but these methods are still limited by high economic cost,difficult operation,incomplete eradication and secondary pollution.Photocatalytic technology attracted much concern of scientists.Traditional photocatalysts such as titanium dioxide are cheap and non-toxic,but they are wide band gap semiconductor,cannot make full use of sunlight,and the photogenerated electrons and holes recombine easily which limit their development and application.In this paper,In order to prepare new type of high efficient photocatalysts and improve the traditional catalyst,binary metallic sulfide and ternary metallic sulfide compound Sn In4S8 were designed and their photocatalytic performance was studied.The main contents of this paper are as follows:?1?One-step in situ hydrothermal fabrication of octahedral CdS/SnIn₄S₈ nano-heterojunction.In this study,octahedral Cd S/SnIn₄S₈ nano-heterojunctions were fabricated by a facile and simple one-step in situ hydrothermal method,and the molar ratio of CdS to SnIn₄S₈ was optimized.The optimal?0.5:1?CdS/SnIn₄S₈ heterojunctions demonstrate the highest visible-light photocatalytic activity with 97.1% degradation efficiency of 2-nitrophenol in 120 min due to the narrowest band gap,the largest BET surface area,the most efficient charge separation and transfer,and the synergistic effect between CdS and Sn In4S8.The mineralization efficiency of 2-nitrophenol and real pharmaceutical wastewater by?0.5:1?CdS/Sn In4S8 is 49.4% and 35% in 10 h and 18 h,respectively.Moreover,CdS/SnIn₄S₈ nano-heterojunctions show excellent reusability in five degradation–regeneration cycles due to its stable surface composition and chemical valence state.The results indicate that CdS/SnIn₄S₈ has a promising prospect in real pharmaceutical wastewater treatment due to high efficiency and excellent stability.?2?Preparation and application of Ag InS2/Sn In4S8 nanocomposites.In this experiment,AgInS₂/SnIn₄S₈ materials were prepared via one-step hydrothermal method using silver chloride,the indium trichloride,stannic chloride and thioacetamide as source of silver,indium,tin and sulfur sources,respectively.The ratio of Ag InS2 to Sn In4S8 was optimized.When the molar amount of AgInS₂ to SnIn₄S₈ is 0.6,Ag InS2/SnIn₄S₈ composite photocatalyst shows the highest photocatalytic activity for degrading 2NP due to large absorption range and visible-light response.AgInS₂/Sn In4S8 composites not only can degrade 2NP and tetracycline,but also had good mineralization efficiency for the actual wastewater.?3?Preparation,characterization and photocatalytic properties of research of PPyPANI/TiO₂ NT composite photocatalyst.Titania nanotube array?Ti O₂ NT?was fabricated by anodization of titanium in an electrolyte containing HF and NaHSO4,and then was crystallized to anatase phase at 500 oC.The crystallized TiO₂ NT was modified with conductive polypyrrole-polyaniline copolymer by cyclic voltammetry technique.The photocurrent response of PPy-PANI/TiO₂ NT composites and the bare annealed TiO₂ NT was 52 and 21 ?A,respectively,indicating that the separation and transfer of photogenerated electron-hole pairs in PPy-PANI/TiO₂ NT is much more efficient than in pure TiO₂ NT.The visible-light photocatalytic activity decreases in following order: PPy-PANI/TiO₂ NT > PPy/TiO₂ NT > PANI/TiO₂ NT > TiO₂ NT.