| In recent years,the use of solar energy to catalyze the organic pollutants by semiconductor photocatalysts are more efficient and environmental friendly method.Therefore,The purpose of this paper is to study new visible light photocatalysts——Ag/Ag3PO4?MoS2/Ag3PO4 and MoS2.Starting from the modification and synthesis of the photocatalysts,a series of micro-nanomaterials with excellent properties and uniform morphologies were prepared.The influence of the materials ratio and the solution's pH for the structure.The possible growth mechanism and photocatalytic mechanism of samples were proposed.1?Preparation and photocatalytic properties of Ag/Ag3PO4 catalystsThe Ag/Ag3PO4 composites with various shapes of sphere,polyhedron and microcube were synthesized by a facile precipitation and subsequently light-reduction route at room temperature.The Ag/Ag3PO4 were characterized in detail.The formation mechanism of the three morphologies of Ag/Ag3PO4 was emphatically discussed.It was found that the growth processes may be related to the concentration of Ag+,the concentration of PO43-,the speed of nucleation and the pH.The Ag/Ag3PO4 composites enhanced photocatalytic performance compared with pure Ag3PO4,moreover,the cube of Ag/Ag3PO4 shown the highest photocatalytic activity and could completely degrade RhB in 7 min.The sphere and polyhedron of Ag/Ag3PO4 required 14min and 70min,respectively,which could be primarily ascribed to the cubic structure of Ag/Ag3PO4 with strong visible light absorption.Finally,the possible photocatalytic mechanism of Ag/Ag3PO4 was also discussed,which was attributed to the the SPR of Ag nanoparticles can be beneficial to the separation of photoelectron-hole pairs.2.Preparation and photocatalytic properties of MoS2/Ag3PO4 composite catalystThe MoS2 nanosheet was prepared by hydrothermal method and then used to modify Ag3PO4 through chemical precipitation method.Five groups of MoS2/Ag3PO4 composites were prepared.The structure,element and so on of the samples were tested by XRD,EDS and SEM,the MoS2 for the photocatalytic properties of Ag3PO4 were studied by DRS and PL.The photocatalytic activity of the MoS2/Ag3PO4 were investigated by degradation of MB.The results shown that the photocatalytic activity of 10wt%MoS2/Ag3PO4 was the best,and the degradation rate of MB reached 100%in 5min.Furthermore,we found that the MoS2 could be used as a good electron acceptor,the electrons on the conduction band of the Ag3PO4 could constantly transferred to the layered MoS2.Finally,The cycle experiments shown that MoS2/Ag3PO4 composite still maintaineda high degradation rate about 85%.3.The Research about Control Synthesis and Photocatalytic Property of MoS2The microspheres and microcubicbox of MoS2 with hollow structure were successfully prepared by template method.Firstly,the different morphology of MnCO3 template were synthesized at the 50 ? water bath.Changing the ratio of MnSO4 and NaHCO3(1:1,1:5,1:10 and 1:15),the morphology of MnCO3 evolved from small cube and sphere to uniform sphere.When adding Na2SO4 to the reaction solution system,and changing the ratio of MnSO4,Na2SO4 and NaHCO3(1:1:1,1:5:5,1:10:10 and 1:15:15),the morphology of MnCO3 evolved from irregular spheroid to uniform cube.And then,the uniform spherical and cubic MnCO3 were selected as the precursor templates,the L-cysteine as a sulfur source.The intermediate compound of MnCO3/MnS/MoS2 were gained via the hydrothermal method.Finally,the hollow structure of MoS2 microspheres and microcubicboxes were obtained by selectively removed MnCO3 and MnS through acid pickling.The product's structure,morphology and elements were characterized.Experiment results on degradation of RhB showed that the hollow microspheres and microcubicboxes of MoS2 exhibited stronger photocatalytic activity,which degradation rate were 3.3 and 2.3 times higher than that of the common MoS2.Therefore,it was worth further researching the application of the hollow microspheres and microcubicboxes of MoS2 in the field of photocatalysis. |
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