ABSTRACT
Barium phosphate (Ba3(PO4)2) is a class of material that has attracted significant attention thanks to its chemical stability and versatility. However, the use of Ba3(PO4)2 as a photocatalyst is scarcely reported, and its use as a photocatalyst has yet to be reported. Herein, Ba3(PO4)2 nanoflakes synthesis is optimized using sol-gel and hydrothermal methods. The as-prepared Ba3(PO4)2 powders are investigated using physicochemical characterizations, including XRD, SEM, EDX, FTIR, DRS, J-t, LSV, Mott-Schottky, and EIS. In addition, DFT calculations are performed to investigate the band structure. The oxidation capability of the photocatalysts is investigated depending on the synthesis method using rhodamine B (RhB) as a pollutant model. Both Ba3(PO4)2 samples prepared by the sol-gel and hydrothermal methods display high RhB photodegradation of 79% and 68%, respectively. The Ba3(PO4)2 obtained using the sol-gel process exhibits much higher stability under light excitation after four regeneration cycles. The photocatalytic oxidation mechanism is proposed based on the active species trapping experiments where O2 â¢â is the most reactive species. The finding shows the promising potential of Ba3(PO4)2 photocatalysts and opens the door for further investigation and application in various photocatalytic applications.
ABSTRACT
Over more than three decades, the scientific community has been contentiously interested in structuring varying photocatalytic materials with unique properties for appropriate technology transfer. Most of the existing reported photocatalysts in the literature show pros and cons by considering the type of application and working conditions. Bismuth titanate oxides (BTO) are novel photocatalysts that raised recently towards energy and environmental-related applications. Most recent advances to developing bismuth titanate-based photocatalysts for the oxidation of organic pollutants in the water phase were reviewed in this report. To counter the potential drawbacks of BTO materials, i.e., rapid recombination of photoproduced charges, and further promote the photoactivity, most reported approaches were discussed, including creating direct Z-scheme junctions, conventional heterojunctions, metal/non-metal doping, coupling with carbon materials, surface modification and construction of oxygen vacancies. In the end, the review addresses the future trends for better engineering and application of BTO based photocatalysts towards the photodegradation of organic pollutants in water under controlled lab and large scales conditions.
