Table 8.

Bi-based nanocomposite/heterojunction photocatalysts for antibiotic remediation.

Photocatalyst	Target antibiotic	Optimum experimental conditions	Source of light	Degradation (%)	Ref.
Remarks on active species
Azadirachta indica leaf extraction/BiOBr0.2I0.8	amoxicillin trihydrate	optimum reaction time: 300 min; dosage of catalyst: 1 g/L; initial concentration of antibiotic: 20 mg/L	visible light	93.2	[168]
The prime active species are h+ and •O2− while •OH radicals play a minor role during the photocatalytic process.
Bi2WO6/C-dots/TiO2	levofloxacin	optimum reaction time: 90 min; dosage of catalyst: 0.075 g/L; initial concentration of antibiotic: 10 mg/L	sunlight	99.0	[169]
The •OH radicals play a key role in the degradation process while h+ and e− contributed to the production of the active species.
Ag/AgBr/BiVO4	ciprofloxacin	optimum reaction time: 120 min; initial concentration of antibiotic: 10 mg/L	visible light	91.4	[126]
Hydroxyl radicals, h+, and •O2− were the main species that contributed to the degradation process
BiVO4/TiO2/RGO	tetracycline, chlortetracycline, oxytetracycline, doxycycline	optimum reaction time: 120 min; initial concentration of antibiotic: 10 mg/L, pH 3	visible light	96.2, 97.5, 98.7, 99.6	[170]
Both •O2− and •OH were the key species that participated in the photocatalytic degradation process.
g-C3N4/BiOBr on carbon fibre	tetracycline	optimum reaction time: 120 min; g-C3N4 nanosheets (thickness: ca. 30 nm, diameter: 0.4–1.0 μm) and BiOBr layer (thickness: ca. 25 nm, diameter: 200–500 nm); carbon fiber: (area: 5 × 5 cm2, weight: 0.15 g); initial concentration of antibiotic: 20 mg/L	visible light	86.1	[171]
•OH, h+ and •O2− were revealed to have participated in tetracycline degradation.
Bi2O3–TiO2/activated carbon	sulfamerazine	optimum reaction time: 120 min; dosage of catalyst: 1 g/L; initial concentration of antibiotic: 20 mg/L	visible light	95.5	[172]
h+ and •O2− participated in sulfamerazine degradation.
biochar@ZnFe2O4/BiOBr, biochar@BiOBr, ZnFe2O4/BiOBr	ciprofloxacin	optimum reaction time: 60 min; dosage of catalyst: 0.5 g/L; initial concentration of antibiotic: 15 mg/L	visible light	65.26, 47.1, 48.76	[128]
The results from the scavenger experiments revealed that radical h+, •OH, and •O2− radicals contributed to the photocatalytic degradation process.
AgI/Bi4V2O11	sulfamerazine	optimum reaction time: 60 min; dosage of catalyst: 1 g/L; initial concentration of antibiotic: 10 mg/L	visible light	91.47	[173]
•OH, h+ and •O2− were all involved in sulfamerazine degradation.
BiOCl/g-C3N4/Cu2O/Fe3O4, BiOCl/g-C3N4/Cu2O, BiOCl/Cu2O/Fe3O4, BiOCl/g-C3N4/Fe3O4, BiOCl/g-C3N4, BiOCl/Cu2O	sulfamethoxazole	optimum reaction time: 120 min; dosage of catalyst: 0.2 g/L; initial concentration of antibiotic: 25 mg/L	visible light (Xe) and sunlight	Xe: 99.5; sunlight: 92.1, 85.3, 83.8, 80.7, 63.5, 59.4	[129]
The main reactive species identified through scavenging tests were •O2− and •OH.
Bi2WO6/g-C3N4	ceftriaxone sodium	optimum time: 120 min; dosage of catalyst: 1 g/L; initial concentration of antibiotic: 10 mg/L	visible light	94.5	[174]
h+ and •O2− radicals played a more significant role in the photocatalytic process then •OH.
AgI/BiOIO3	tetracycline, chlortetracycline	optimum reaction time: 350 min; dosage of catalyst: 0.5 g/L; initial concentration of antibiotic: 10 mg/L	visible light	tetracycline: 45.3, chlortetracycline: 39.1	[175]
From BiOIO3, h+ cannot sufficiently oxidise H2O molecules to form •OH radicals. While the h+ in AgI oxidises OH– to produce •OH radicals, the electrons in AgI converted O2 to radical •O2−. All contributed to the degradation.
BiOBr/Bi2S3, BiOBr	ciprofloxacin, ofloxacin	optimum reaction time: 60 min; dosage of catalyst: 1 g/L; initial concentration of antibiotic: 20 mg/L	indoor fluorescent light	97.2, 89.28, 52.1, 44.21	[176]
•O2− and h+ were shown to be the primary degrading species in scavenger experiments.