| With the worsening of indoor air pollution,people's awareness of self-protection is gradually strengthened.It is necessary to develop environmentally friendly photocatalytic air purifying coatings that can degrade harmful substances.In order to have these effects for traditional water-based coatings,high efficient photocatalysts must be added,and photocatalysts must be well dispersed in them.Ti O2 photocatalyst has the advantages of low price and stable properties,but it needs to be modified to make it more efficient in the photocatalytic reactionIn this thesis,Ti O2 photocatalysts were prepared by metal doping,activated carbon supported,semiconductor composite and so on.The structure and morphology of Bi-Ti O2 photocatalysts were investigated by means of XRD,SEM,EDS and UV.Compared with pure Ti O2,the photocatalytic activity of Bi-Ti O2 was improved.Different preparation methods were investigated by single factor experiments,effects of ultrasonic time and the content of activated carbon in activated carbon /Bi-Ti O2 photocatalyst to the photocatalytic performance.The results show that the dispersion method in ultrasonic,ultrasonic time 160 min,the content of activated carbon under the condition of 10% /Bi-Ti O2 of activated carbon is the appropriate condition to contain the photocatalyst with the better catalytic effect.And the degradation rate of rhodamine B is up to 93% in visible light for 2hours.The resut of cyclic experiments show that photocatalysts prepared in the above mention have the good stability.The dispersion for activated carbon/Bi-Ti O2 powder was characterized by trial experiments,settlement experiments,spectrophotometric method and TEM.The results showed that the dispersant nekal,sodium dodecyl benzene sulfonate,the composite dispersant of nekal/Tween 20 and sodium dodecyl benzene sulfonate/hexadecyl trimethyl ammonium bromide have the good dispersity,and the optimal amount of dispersant were 1%,0.5%,1 %/ 0.05% and 0.5% / 0.05%,respectively. |
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