| Summary: | 碩士 === 國立中興大學 === 環境工程學系所 === 106 === A visible-light-driven graphitic carbon nitride/reduced graphene oxide/α-Sulfur composite (CNRGOS8) was synthesized as efficient photocatalysts for environmental applications. The photocatalytic reactivity of the fabricated CNRGOS8 was determined by the degradation of Rhodamine B (RhB) and tetracycline (TC). The effects of pH, mixed ratio of catalysts, dosage of photocatalyst were optimized, and the reaction kinetics and reaction pathway were studied.
The results indicated the optimized pH values for RhB and TC degradation was 3 and 7, respectively. In addition, no deterioration of the efficiency was found for CNRGOS8 (70:5:25) after 5 cycles of operation. Such a result was indicative of a prolonged lifetime of the CNRGOS8 (70:5:25). With probing by the scavengers, 2-Propanol (·OH capture reagent), benzoquinone (O2•－ capture reagent) and sodium oxalate (h+ capture reagent), the major reactive species were identified as superoxide radicals and hydroxyl radicals.
The abundant natural organic matter such as humic acid (HA) oftentimes coexists with the pollutants in the aquatic environment, which may affect the efficiency and alter reaction pathways of photodegradation of the pollutants. An enhanced electron transfer and reactive oxide species production were found for CNRGOS8 (70:5:25) in the presence of humic acid. However, the overall removal efficiency of the pollutants was suppressed due to the competition between CNRGOS8 (70:5:25) and the coexisting HA for the active sites.
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