2.4. Photocatalytic experiment
The photocatalytic experiment was carried out in a photochemical reactor. A xenon lamp (1000 W) simulates sunlight. Weigh 50 mg of photocatalyst, scatter it into a beaker with 50 ml of 10 mg/L methyl orange, put it in the photochemical reactor, close the box door to avoid alternating light and dark, stir and adsorb for 20 minutes, turn on the light source, take 4 ml of samples every 5 minutes, and take the supernatant after centrifugation. The absorbance of the methyl orange solution before and after the reaction was measured by a UV-Vis spectrophotometer at 464 nm. During the reaction, hold the reaction suspension at about 10 °C. Beer Lambert’s Law was used to calculate the degradation rate of photocatalytic degradation of MO. Characterization of photocatalytic degradation of MO using the kinetic equation method:
\(\frac{\complement_{t}}{\complement_{0}=}\frac{A_{t}}{A_{0}}\) (1)
\(A_{t}+Kt=-ln(\frac{C_{t}}{C_{0}})\) (2)
A0 and At show the absorbance of the solution at the initial and post-irradiation times, and C0 and Ct show the corresponding initial concentration of the solution and the solution concentration after t time.
Catalyst cycle stability analysis: collect the photocatalyst after each use, wash and dry it many times, and repeat the above steps twice to investigate its cycle stability.
Free radical capture experiment: Using isopropanol (IPA) as hydroxyl radical (OH·) trapping agent, triethanolamine (TEOA) as hole (h+) trapping agent, and p-benzoquinone (BQ) as superoxide radical (O- 2· ) trapping agent, the active factors in the catalytic degradation process of the objective contaminant were analyzed through the change in degradation efficiency before and after the addition of trapping agent.
3. Results and Discussion