Photochemical oxidation txoj kev rau degradation ntawm cov pa phem muaj xws li cov txheej txheem uas muaj ob qho tib si catalytic thiab non-catalytic photochemical oxidation. Cov qub feem ntau siv cov pa oxygen thiab hydrogen peroxide ua oxidants thiab tso siab rau ultraviolet (UV) lub teeb los pib oxidation thiab decomposition ntawm cov pa phem. Cov tom kawg, hu ua photocatalytic oxidation, feem ntau yuav categorized li homogeneous thiab heterogeneous catalysis.
Nyob rau hauv heterogeneous photocatalytic degradation, ib tug npaum li cas ntawm photosensitive semiconductor khoom yog nkag mus rau hauv cov pa phem, ua ke nrog ib tug npaum li cas ntawm lub teeb hluav taws xob. Qhov no ua rau excitation ntawm "electron-qhov" khub ntawm photosensitive semiconductor nto nyob rau hauv lub teeb raug. Dissolved oxygen, dej molecules, thiab lwm yam khoom adsorbed ntawm lub semiconductor cuam tshuam nrog cov "electron-qhov" khub, khaws cia ntau zog. Qhov no tso cai rau cov khoom siv semiconductor kom kov yeej cov tshuaj tiv thaiv thermodynamic thiab ua raws li cov catalysts hauv ntau cov tshuaj tiv thaiv catalytic, tsim cov oxidative radicals xws li •HO. Cov radicals no pab txhawb kev degradation ntawm cov pa phem los ntawm cov txheej txheem xws li hydroxyl ntxiv, hloov pauv, thiab hloov hluav taws xob.
Photochemical oxidation txoj kev encompass photosensitized oxidation, photoexcited oxidation, thiab photocatalytic oxidation. Photochemical oxidation sib txuas cov tshuaj oxidation thiab hluav taws xob los txhim kho tus nqi thiab oxidative muaj peev xwm ntawm oxidation cov tshuaj tiv thaiv piv rau cov tshuaj oxidation los yog hluav taws xob kho. Lub teeb ultraviolet feem ntau yog siv los ua cov hluav taws xob hauv photocatalytic oxidation.
Tsis tas li ntawd, ib qho kev txiav txim siab ntawm cov oxidants xws li hydrogen peroxide, ozone, lossis qee cov catalysts yuav tsum tau nkag mus rau hauv dej. Txoj kev no muaj txiaj ntsig zoo rau kev tshem tawm cov organic molecules me me, xws li dyes, uas nyuaj rau degrade thiab muaj toxicity. Photochemical oxidation cov tshuaj tiv thaiv tsim muaj ntau heev reactive radicals nyob rau hauv dej, uas nkag mus cuam tshuam cov qauv ntawm cov organic tebchaw.
Post lub sij hawm: Sep-07-2023
