Photocatalytic improvement mechanism of SnO2/Sn-doped g-C3N4 Z-type heterojunctions for visible-irradiation-based destruction of organic pollutants: Experimental and RSM approaches
Yossor R. Abdulmajeed, Saad H. Ammar, Zaid H. Jabbar, Hind J. Hadi, Mohammed D. Salman, Alaa J. Awadh
Abstract
This work investigated the possibility of applying SnO 2 /Sn-doped g-C 3 N 4 hybrid as an efficient photocatalyst for visible light-based degradation of ibuprofen (IBP). Response surface methodology (RSM) has been adopted to optimize the IBP photodegradation. The conditions were initially fixed at photocatalyst dose = 0.2 g/L, Solution pH = 7, and IBP concentration = 10 mg/L in order to assess the SnO 2 /Sn-doped g-C 3 N 4 activity, which exhibited 91% IBP destruction after 90 min. Then, the process variables (IBP concentration, pH, and photocatalyst dose) were adjusted based on the Box-Behnken Design (BBD). The experimental IBP photodegradation was exceedingly correlated with that value predicted by the obtained quadratic model (R 2 = 0.993, F-value =79.19, and P-value < 0.0001). The IBP photodegradation tests exhibited that the SnO 2 /Sn-doped g-C 3 N 4 dose of 0.6 g/L, solution pH of 11, and IBP concentration of 10 mg/L were the optimal values. The photocatalyst dose was specified as the major factor in the process. The boosted photoactivity was due to the created Z-type heterojunction among SnO 2 and Sn-doped g-C 3 N 4 , which provides an excellent separation of photogenerated charge-carriers. Accordingly, we explored the reaction mechanism in light of trapping studies. Besides, the stability of SnO 2 /Sn-doped g-C 3 N 4 hybrid photocatalyst was tested.