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Microwave-Driven Hexagonal-to-Monoclinic Transition in BiPO4: An In-Depth Experimental Investigation and
Ana C M Tello1,2, Marcelo Assis1, Ricardo Menasce1
1Chemistry Department, CDMF, LIEC, Federal University of São Carlos, P.O. Box 676, São Carlos, São Paulo 13565-905, Brazil.
Microwave irradiation rapidly transforms hexagonal bismuth phosphate (BiPO4) to its monoclinic phase, enhancing its photocatalytic activity for Rhodamine B degradation under visible light.
Area of Science:
- Materials Science
- Solid State Chemistry
- Photocatalysis
Background:
- Bismuth phosphate (BiPO4) exists in hexagonal and monoclinic polymorphs with distinct properties.
- Understanding phase transformations is crucial for optimizing material performance.
Purpose of the Study:
- To investigate the microwave-induced phase transformation of BiPO4 from hexagonal to monoclinic.
- To elucidate the impact of this transformation on photocatalytic efficiency.
- To correlate material properties with observed performance.
Main Methods:
- Experimental synthesis using microwave irradiation.
- First-principles calculations using density functional theory (DFT).
- Characterization techniques including scanning electron microscopy (SEM).
Main Results:
- Microwave irradiation efficiently converts hexagonal BiPO4 to the monoclinic phase within minutes.
- DFT calculations revealed key structural, electronic, and vibrational properties influencing the phase transition.
- Optimized BiPO4 crystals exhibited excellent Rhodamine B photodegradation under visible light.
Conclusions:
- The hexagonal-to-monoclinic phase transition in BiPO4 is irreversible and influenced by low vibrational modes.
- Enhanced photocatalytic activity is linked to surface energy and exposed crystal facets.
- Findings aid in designing efficient electronic devices and photocatalysts.
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