1. Look at the color
Due to different preparation methods and uses, photocatalysts show different colors. Common colors are milky white, light yellow, light blue, or colorless liquid, translucent liquid. If the color is dark, it is a shoddy photocatalyst product.
2. Light scattering
When the visible light through the sol produces an obvious scattering effect, that is the Tyndall phenomenon. Colloid has the Tyndall phenomenon, while the solution does not, so you can use the Tyndall phenomenon to distinguish between colloid and solution. No matter what color the photocatalyst solution should have the Tyndall phenomenon. If there is no Tyndall phenomenon, it is a shoddy photocatalyst product.
3. Stability
Photocatalyst dispersion technology is better, generally will not be stratified, precipitation, but if the nanoparticle size is small, no dispersant, then there may be a little cohesion phenomenon for a long time, use a few shakes can be, does not affect the use of performance. If precipitation occurs easily and more precipitation, it is a shoddy photocatalyst product. Shoddy products due to poor material selection, poor dispersion process, and other reasons lead to a large number of precipitation.
This precipitation is not the so-called high content of titanium dioxide nanoparticles due to material and technical reasons. One reason is that ordinary titanium dioxide is fake nanoscale titanium dioxide, with particles thousands of times larger; another reason is that the production process is inadequate, with titanium dioxide nano-aggregate state, much larger than 100-nanometer national nanotechnology standards.
4. Look at the bubbles
Shake the photocatalyst with force to produce a small number of clear water bubbles, and disappears quickly; if shaken with soap bubble-like bubbles, and a long time to disappear, and it is a shoddy photocatalyst product.
5. Look at the photocatalyst color fading function
Methyl blue diluted drops in the sprayed photocatalyst on the porcelain, light, blue quickly disappeared. If the color can not fade or fade is not obvious, it is a shoddy photocatalyst product.
6. See the effect of time
Photocatalysts through the surface decomposition of organic matter, so it takes a period to have a more pronounced effect on governance, high-quality photocatalysts generally need 7-15 days to decompose organic matter.
7. Look at the light conditions
Photocatalyst is through the absorption of light energy after the performance of the catalyst, no light-state photocatalyst has no energy source, so no effect. According to the information, the current 550nm products can be mass production is still minimal.
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