What is photocatalytic dye degradation?
The standard experimental set up for dye degradation photocatalysis is by using a UV lamp to provide energy for the creation of oxidizing radicals. Photocatalysis is the addition of light to a semiconductor oxide/sulphide that results in electrons moving from the valence band to the conduction band.
What is Congo red indicator used for?
Congo red was formerly used to dye cotton but has been superseded by dyes more resistant to light and to washing. It is still used in histology to stain tissues for microscopic examination, and to serve as an acid-base indicator, since it turns red in the presence of alkalies and blue when exposed to acids.
Is Congo red stain acidic or basic?
Congo red is an acid-base indicator dye. In free solution the colour and absorption characteristics of Congo red depend not only on the pH but are also governed by the nature of the solvent environment.
What is the principle behind the stain of the cell wall using New Fuchsin and Congo red?
Congo red is a selective decolourising agent it selectively decolourises the less acidic portion that is cytoplasm. Hence, cell wall remains stained by 0.5% New fuchsin stain and cytoplasm appears colourless.
Why TiO2 is used as photocatalyst?
Titanium dioxide (TiO2) has been widely used as a photocatalyst in many environmental and energy applications due to its efficient photoactivity, high stability, low cost, and safety to the environment and humans.
How do you dissolve Congo red?
1% potassium hydroxide solution: • Dissolve 1 g of potassium hydroxide in 50 ml of distilled/demineralized water.
What is the purpose of maneval’s stain?
Use to stain negatively charged structures of bacteria red.
What is the important difference between how stains used for simple staining and for negative staining penetrate bacterial cells?
There is no difference in how these stains penetrate the cells. The inherent charges of the simple stains will ensure that those stains can penetrate into and remain within bacterial cells, while negative stains are repelled and will remain outside the cells.