Research On Tin-based Oxide Photocatalytic Materials

With the development of society and the process of industrialization,the energy shortage and environmental contamination have posed a severe challenge to human beings.Environment protection and sustainable development has become the necessary choice of modern society.Photocatalytic degradation becomes a promising technology for the treatment of water because it is cheap and environmentally friendly.Photocatalytic reaction has the advantages of innocuity,high efficiency and without secondary pollution.This paper systematically describes the basic principle and application of the photocatalytic technology,the improvement of the photocatalytic properties of tin oxide photocatalyst,and it elaborates the different morphologies of SnO,SnO/SnO₂ composite,PANI/SnO₂ composite materials that they were prepared and studied by X-ray diffraction（XRD）、Scanning electron microscopy（SEM）、transmission electron microscope（TEM）、Fourier Transform Infrared Spectoscopy（FT-IR）and photoluminescence（PL）.The photocatalysts were detected the structure,morphology and photocatalytic properties,the photocatalytic mechanism.The specific research contents of this paper are listed as follows:1、The SnO were synthesized by the hydrothermal of SnCl₂·2H₂O and NaOH,by controlling the ratio of solvent to synthesis different morphologies of the SnO.The SnO photocatalyst with different morphologies were characterizeby XRD/SEM/TEM and tested the photocatalytic activity for methyl orange.The results showes that the photocatalytic activity of flower like SnO is 1.5 times better than sheet like SnO.The photocatalytic mechanism of SnO indicates that the photocatalytic activity of flower like SnO is better than that of sheet like SnO probably because that the light can reflect several times through the flake of flower like SnO,improving the photon absorption of itself.2.The SnO/SnO₂ composite material was prepared by hydrothermal method with SnCl₂·2H₂O,SnCl₄·5H₂O and ammonia as raw materials.While the ratio of SnO/SnO₂ was prepared by controlling the ratio of raw materials.The formation of heterojunction structure lets the photocatalytic activity of the photocatalyst increase to a higher level.The photocatalytic activity of SnO:SnO₂ =1:1 composite material was the best in the photocatalytic activity of methyl orange,while the photocatalytic degradation of methyl orange（MO）is 99.8%after 20 min.The photocatalytic mechanism of SnO/SnO₂ composite material shows that the heterojunction structure decreases the recombination of the photogenerated electron hole pairs of SnO/SnO₂ and enhances the photocatalytic activity.3.The spherical PANI/SnO₂ composite photocatalyst was synthesized by the spherical like SnO₂ and conductive PANI.The photocatalytic activity of the samples was evaluated by degradation of methyl orange（MO）aqueous solution under ultraviolet light irradiation.The obtained results show that the photocatalytic activity of PANI/SnO₂ samples first increases with the increase amount of PANI and reaches a maximum with 1%PANI/SnO₂,and then decrease as the amount of PANI is further increased.The enhancement of photocatalytic performance is attributed to the combination of PANI.It is also found that photodegradation of MO fits first-order kinetics equation.The present work may provide an insight into the fabrication of delicate composite photocatalysts with excellent performance.