Carbon/Mn3O4/SrTiO3 microsphere photocatalyst for the efficient removal of high-concentration methylene blue from water

BACKGROUND: With the development of the textile and dye industry, a large amount of dye wastewater has been discharged. Semiconductor photocatalysis has been widely used in the treatment of environmental pollution, so it is very important to study efficient, nontoxic and stable photocatalysts. RESULTS: In this study, a microspherical activated carbon/Mn3O4/SrTiO3 composite photocatalyst with high catalytic activity was synthesized using sol-gel and chemical precipitation methods. The photocatalyst was characterized through X-ray diffraction, scanning and transmission electron microscopy, energy dispersive spectroscopy, X-ray photoelectron spectroscopy, photoluminescence, Electrochemical impedance spectroscopy, electron paramagnetic resonance spectroscopy and photocurrent measurements, and the effects of the initial methylene blue (MB) concentration and pH on the catalytic performance of the photocatalyst were investigated. The results revealed that the MC/Mn3O4/SrTiO3 composite has large light absorbance, and it can effectively inhibit photoinduced electron-hole pair recombination. The catalyst exhibited high photocatalytic degradation activity, and the degradation efficiency of MB at 300 ppm and pH 7 reached 99% after 80 min of UV light irradiation. The photodegradation process conformed to the pseudo-first-order kinetic model. Recyclability experiments showed that MC/Mn3O4/SrTiO3 composite has high stability, and the degradation rate of MB is > 70% after three repeat uses. CONCLUSIONS: This work provides a new method for finding low-cost, high-performance materials that can be modified and put into industrial use. (c) 2023 Society of Chemical Industry (SCI).