If I understand this correctly.....

UV photons have considerably higher energy than IR photons.

UV photons have enough energy to break bonds, or promote the species to an electronically excited and highly reactive state.

UV can cause cancer, photobleaching, photochemical reactions.

IR photons can excite vibrations in bonds, increasing their energy which is manifest as heat.

in IR the N triple bonds is lies about at 2500 cm-1

If I understand this correctly.....

UV photons have considerably higher energy than IR photons.

UV photons have enough energy to break bonds, or promote the species to an electronically excited and highly reactive state.

UV can cause cancer, photobleaching, photochemical reactions.

IR photons can excite vibrations in bonds, increasing their energy which is manifest as heat.

Ultraviolet (UV) radiation will normally degrade a material more than infrared (IR) radiation (with the same number of photons) as the photon energy is larger in the UV wavelength range than in the IR wavelength range. The photon energy (i.e. energy per photon) needs to be larger than the chemical bond energy in order to break this chemical bond. The photon energy is given by E = hf = hc/s, where E = photon energy, h = Planck constant, f = photon frequency, c = light velocity and s = photon wavelength. UV radiation has short (small) wavelengths and thus large energy per photon, whereas IR radiation has long (large) wavelengths and hence small energy per photon (when comparing UV and IR). See for example the article:

B. P. Jelle, A. Gustavsen, T.-N. Nilsen and T. Jacobsen, ”Solar Material Protection Factor (SMPF) and Solar Skin Protection Factor (SSPF) for Window Panes and other Glass Structures in Buildings”, Solar Energy Materials and Solar Cells, 91, 342-354, 2007.

Article Solar material protection factor (SMPF) and solar skin prote...

https://www.researchgate.net/publication/229379225_Solar_material_protection_factor_SMPF_and_solar_skin_protection_factor_SSPF_for_window_panes_and_other_glass_structures_in_buildings

Thank you for the useful information.

What about human skin and eyes?

Greenhouse effect?

Is the comparison available!

UV is more destructive when comes in contact with flesh.

UV radiation is clearly more damaging to human skin and eyes. You may burn your skin and your eyes, e.g. become "snowblind" (caused by large reflection of UV radiation from the snow into your eyes and which your eyes don't "detect" before it's too late).

About solar skin protection factor (SSPF) see the referred article in my earlier post, and for a more extensive review on all solar radiation glazing factors see e.g. the following article:

B. P. Jelle, ”Solar Radiation Glazing Factors for Window Panes, Glass Structures and Electrochromic Windows in Buildings - Measurement and Calculation”, Solar Energy Materials and Solar Cells, 116, 291-323, 2013.

Article Solar radiation glazing factors for window panes, glass stru...

https://www.researchgate.net/publication/257375682_Solar_radiation_glazing_factors_for_window_panes_glass_structures_and_electrochromic_windows_in_buildings-Measurement_and_calculation

IR will be more useful

Bjørn Petter Jelle  and Hugh J Byrne  comments are absolutely perfect. However I have some comments and want their opinion. In case of incident solar spectrum, availability of UV is 5-10% where as NIR is  more than 50%. Thus , though UV has higher adverse effect or impact due to shorter wavelength , NIR has drastic impact due to total percentage .

Yes, if it is much less UV than IR (or near IR (NIR) from the solar radiation) then IR and/or NIR may become more important. And in fact also with only moderate amounts of NIR (and IR), this radiation may contribute rather much to the degradation processes as long as the NIR and IR radiation contribute to higher temperatures (see below). UV radiation and the shorter wavelengths of the visible (VIS) radiation (light) will often have photons with larger photon energy than chemical bonds in various materials they are impacting, and may thus start a photodegradation process, which longer wavelengths of the VIS radiation and NIR (and IR) cannot do as their photon energies are smaller than the chemical bond energy.

However, the radiation of the longer wavelengths may still contribute to increase the temperature, and as many chemical reactions follows the Arrhenius equation the rate of the degradation processes for these ones will then increase exponentially with increasing temperature. That is, the contribution from the parts of UV, VIS, NIR and IR radiation, which have too small photon energy to break the chemical bonds of the specific material in question, may still contribute very much to the total degradation due to their contribution to increase the temperature and thus increase the rate of the degradation processes exponentially with increasing temperature. This is valid as long as these chemical reactions are already running, e.g. initiated by UV photons with high energy per photon.

See e.g. various details, examples and discussions in the following article:

B. P. Jelle, ”Accelerated Climate Ageing of Building Materials, Components and Structures in the Laboratory”, Journal of Materials Science, 47, 6475-6496, 2012.

Article Accelerated climate ageing of building materials, components...

https://www.researchgate.net/publication/258665795_Accelerated_climate_ageing_of_building_materials_components_and_structures_in_the_laboratory

Hi Aritra - hope all is well!!

I think the discussion from Bjorn is very useful - I am not aware to what extent the synergistic effects of UV/NIR have been studied, particularly in the case of disease.

The information shared is useful for designing my experiment.

Thank you.