Structural, Optical and Photocatalytic Activity of α-Bi2O3/Bi2O2CO3/(BiO)4CO3(OH)2 Ternary Multi-heterojunction Nanoflakes Synthesized via Submerged DC Electrical Discharge in Urea Solution

In this research, novel α-Bi 2 O 3 /Bi 2 O 2 CO 3 /(BiO) 4 CO 3 (OH) 2 multi-heterojunction photocatalytic nanoflakes are fabricated via submerged DC electrical arc discharge in urea in water solution. FT-IR, XRD, EDS and PL results conform the formation of α-Bi 2 O 3 /Bi 2 O 2 CO 3 /(BiO) 4 CO 3 (OH) 2 multi-heterojunction. Formation of nanoflake morphology are revealed by FE-SEM, TEM images. Based on UV-visible results the calculated band gap energies are in the range between 2.7 and 3.0 eV for fresh sample and after one month. The photocatalytic performance of sample is investigated via degradation of methylene orange (MeO) under visible light irradiation. α-Bi 2 O 3 /Bi 2 O 2 CO 3 / (BiO) 4 CO 3 (OH) 2 exhibited much higher photocatalytic activity than Bi 2 O 2 CO 3 , Bi 2 O 3 and Bi 2 O 3 /Bi 2 O 2 CO 3 . Also, stable photodegradation efficiency of sample after four cycles reveal the long term stability and reusability of synthesized photocatalyst. PL intensity show improved separation rate of electrons and holes and so better photocatalytic performance of multi-heterojunction in compared to single phase photocatalyst. The enhanced photocatalytic activity can be ascribed to the formation of multi-heterojunctions, flake morphology and intrinsic internal electric field (IEF). Multi-heterojunction nanoflakes enhance the absorbance of visible light and facilitate the separation and transport of photogenerated electron-holes through large IEF which enhance the photocatalytic activity. Our work offers an effective method for production of innovative bismuth based photocatalyst with excellent prospective for degradation of environmental pollutions and light harvesting for renewable energy generation under visible-light.