Preparation Of Molybdenum Supported Materials And Their Selective Adsorption Properties For Heavy Metals

A large number of harmful heavy metal ions,such as Ag（I）,are discharged into the environment through industrial waste water and cause significant harm to ecosystems and human health.Specifically,Ag（I）is highly toxic to aquatic organisms and will accumulate in humans.Causes multiple diseases of the body.But at the same time,silver is a precious metal with high added value,which can be used in a variety of industries.Therefore,it is of great significance to remove Ag（I）from water and recycle silver.Traditional powder adsorbents have the disadvantages of being difficult to recycle and prone to secondary pollution,while carrier adsorbents fill the shortcomings of traditional powder adsorbents.Therefore,this study targeted silver ions as the target pollutant.Because of its unique physical and chemical structure,molybdenum-based materials have their unique advantages in heavy metal adsorption and are considered to be one of the most effective adsorbents.In this paper,molybdenum-based materials are supported on different carriers to study their adsorption performance on silver ions.The details are as follows:1.An amorphous molybdenum oxide film Mo Ox@FTO was prepared on a conductive glass FTO by electrochemical cyclic voltammetry.And XRD analysis confirmed that this Mo Ox is amorphous.According to XPS analysis,this Mo Ox thin film is Mo（V）,Mo（VI）with mixed valence states.The adsorption capacity of Ag（I）reached an ultra-high 3108.02 mg/g.XRD,XPS,and SEM analysis confirmed that the product after Ag（I）adsorption was elemental silver.In addition,through mechanism analysis,it can be found that the removal mechanism of Mo Ox@FTO material is mainly reduction.It is also obtained through selective adsorption experiments that the Mo Ox@FTO material has an extremely high selectivity coefficient for Ag（I）.It was also confirmed through anti-interference experiments that the Mo Ox@FTO material can not affect its adsorption performance at p H=1.In addition,under the conditions of salinity and interference ionic humic acid,it did not adsorb the adsorbent.The performance is suppressed,and Mo Ox is successfully loaded on FTOs of different sizes,which shows that this electrochemical synthesis method has certain generalization.According to the above conclusions,this Mo Ox@FTO material has the prospect of practical wastewater treatment applications.2.In order to investigate the adsorption of Ag（I）on amorphous molybdenum oxide Mo Ox in the flow reaction,an amorphous molybdenum oxide film Mo Ox@carbon cloth was prepared on a conductive glass carbon cloth by electrochemical cyclic voltammetry.Flow adsorption experiments performed in a flow reactor have super high selectivity for Ag（I）.XRD also confirms that Ag trapped on the surface of Mo Ox@carbon cloth is elemental silver,further illustrating that this amorphous Mo Ox is The flow reactor also has the ability to transform Ag（I）in water into elemental silver.In addition,it was confirmed by UV spectrophotometry that Mo（V）was oxidized to Mo O4^2-,which is the raw material for our synthesis of amorphous Mo Ox thin films.Using this method to treat Ag（I）in actual wastewater does not produce secondary pollution,which is in line with the concept of green chemistry.The conversion of Ag（I）to Ag（0）is realized in the flow reactor,and the Mo Ox carrier material has the potential to treat silver-containing wastewater in industry.3.Mo S₂ was successfully loaded on the four different carriers of titanium mesh,tungsten mesh,molybdenum mesh,and carbon cloth by hydrothermal method.Analysis by SEM,TEM,and XRD.Different carriers will affect the micro-morphology and crystal form of Mo S₂ during hydrothermal synthesis.And through subsequent adsorption isotherms and adsorption rates,different morphologies and crystal forms of Mo S₂ can be obtained.In the process of adsorbing Ag（I）,their adsorption capacities and adsorption rates are different.Combining the above conclusions,it can be obtained that the carrier affects the micro morphology and crystal form of the Mo S₂ adsorbent,thereby affecting the adsorption of Mo S₂ on the heavy metal Ag.It is instructive for the selection of subsequent carrier adsorbents in the carrier.