Fabrication of Sm2(WO4)3/g-C3N4 heterojunction for boosting photodegradation of methyl parathion and ofloxacin: Characteristics, mechanism insight and pathways

초록

This paper describes a novel Sm-2(WO4)(3)@g-C3N4(SmW@CN) heterojunction photocatalyst system thatwas fabricated viaa simple hydrothermal route and followed by ultrasonic treatment. The crystallographic properties, physicochemical parameters, morphological features, and optical information were confirmed byP-XRD, SEM-EDX, TEM, XPS, BET, UV-DRS, and PL analysis.The SmW@CN shows fabulous photodegradation activity against hazardous methyl parathion (MP) and ofloxacin (OFX) under visible light. Energy gap values of g-C3N4, Sm-2(WO4)(3) and SmW@CN are 2.7, 3.3 and 2.6 eV respectively.The investigation finds that, the specific surface area of the SmW@CN nanocomposite could reach 31.5 m(2)g(-1) when its mass ratio of g-C3N4 and Sm-2(WO4)(3) is 8.6 m(2)g (-1).The complete degradation of MPand OFX was achieved within 80 and 40 min of irradiation, respectively. Interestingly, the enhanced photocatalytic properties could be attributed to the synergetic effects of Sm-2(WO4)(3) and g-C(3)N(4)whichinhibits the rapid recombination of e(-) h(+)charge carriers at the interface of the photocatalyst. The oxidative radicals quenching experiment portrayed the O-2(center dot-) and (OH)-O-center dot radicals that play a critical role in the photodegradation process. Furthermore, the tentative photocatalytic mechanism of SmW@CN heterojunction was ultimately provided in detail. Lastly, a feasible charge separation pathway was suggested to explain the development of the reactive oxidative species and GCMS- analysis was utilized to track the photodegradation process of OFX. In addition,catalyst laid out excellent durability over a cycle of 5th consecutively runs exhibiting only 12% reduction resulting from the fifth cycle. This work depicts versatility of the SmW@CN composite with its ability to perform photocatalysis adaptability in terms of detoxifying both organic and inorganic contaminants in waste water treatment.

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