Improving sunlight-photocatalytic activity of undoped and phosphorus doped MnO2 with activated carbon from bio-waste with nanorods morphology

Abstract

• P-MnO 2 /AC nanoparticles for photocatalytic activity were synthesized using a hydrothermal technique. • The evenly dispersed AC established good contact with the P-MnO 2 . • Under sunlight irradiation, photocatalytic degradations of MO and RhB dyes are investigated. • The photocatalytic degradation efficiency of the MO and RhB dyes was almost 95%. • P-MnO 2 /AC increased the efficiency of photogenerated electron-hole pair separation and the lifetime of photogenerated electrons substantially . Based on the contributions of phosphorus and Activated carbon (AC) and their composite species are great advances in photocatalytic degradation performance. The evenly distributed Phosphorus and Activated Carbon have good contact with MnO 2 . The activated carbon was made from Manikara zapota peel by chemical activation KOH, and by hydrothermal method P-MnO 2 /AC, nanorods were prepared. The evenly distributed AC has good contact with P-MnO 2 . X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) were used to analyze the samples. Morphology of AC, MnO 2 , and P-MnO 2 /AC was studied using SEM, FESEM, and TEM. UV–visible diffuse reflectance spectroscopy (UV–vis DRS) was used to characterize the bandgap values. The bandgap values of MnO 2 , PMAc (1.0), (3.0), and (5.0) of P-MnO 2 /AC are 2.48 eV, 1.99 eV, 1.76 eV, and 1.62 eV, respectively. They confirmed that increasing the quantity of AC reduced the bandgap values. The photocatalytic efficiency of the MnO 2 and P-MnO 2 /AC samples are studied using the photodegradation of MO and RhB dyes under sunlight. The best photocatalytic degradation performance was obtained by P-MnO 2 /AC for MO and RhB dye, which are excellent degradation efficiency of 96.31 % and 97.57 %, respectively. Furthermore, within 180 min, the optimal TOC removal approached 56.4, 80.3, and 87 % for MnO 2 , PMAc (5.0) MO, and RhB, respectively. Moreover, Trapping experiments were characterized by RhB dye PMAc (5.0) of P-MnO 2 /AC. In addition, IPA had the smallest degrading efficiency (11.46 %) with • OH radicals haveing a substantial role. Furthermore, PMAc (5.0) of P-MnO 2 /AC doping was successfully used for five photodegradation cycles with no notable change in activity or crystalline properties by RhB dye. Furthermore, the mechanism of catalytic performance enhancement was addressed. These nanoparticle materials could be used in high-performance photocatalytic applications.