Table 5.

Potential applications of green ZrO₂-based nanocomposites

Green material	Species	Composites	Properties	Potential applications	Ref
Plant	Centaurea cyanus	Ag/Fe3O4/ZrO2	Particle sizes: 30–90 nm, saturation magnetization: 10 emu/g	Catalytic reduction of 4-nitrophenol and methyl orange, 3 cycles with swift reaction time (7.5–8 min)	Rostami-Vartooni et al. (2019)
Plant	Justicia adhatoda	CeO2/ZrO2	Nano-stick like structure (10–15 nm)	Antibacterial against S. aureus, and E. coli, antioxidant ability, anti-biofilm	Pandiyan et al. (2018)
			Narrow band gap (3.37 eV)
Plant	Hevea brasiliensis	Ni-doped ZrO2	Energy gap of 2.4–2.75 eV	Nanoelectronics	Yadav et al. (2021)
Plant	Leucas aspera	Sm-doped ZrO2 (Sm3+/ZrO2+  = 3–11 mol.%)	Highly symmetric nanocubic (Fm-3 m)	High stable and reusability with six consecutive recycles	Gurushantha et al. (2016)
			Band gap of 5.3–5.9 eV	High sunlight-driven degradation of Sm/ZrO2 with 11 mol.% dopant against acid green dye
Plant	Anacardium occidentale	Ag/ZrO2	Monoclinic and tetragonal phases of ZrO2	Not reported	Vivekanandhan et al. (2015)
			Face-centered cubic crystal phase of Ag NPs (5–20 nm) on ZrO2 surface
Plant	Commelina diffusa (-7-hydroxy-4´-methoxy-isoflavon from extract as a reducing and stabilizing agent	Cu/ZrO2	Reduced agglomeration of Cu/ZrO2 with particle size of 18–25 nm	Catalytic reduction of 2,4- dinitrophenilhydrazine, various organic dyes such as congo red, nigrosin, methyl orange in the presence of NaBH4 at room temperature	Hamad et al. (2019)
			Cu/ZrO2 exhibited the good stability up to three days after the synthesis process	Ultrafast reaction time for methyl orange (1 s), dinitrophenilhydrazine (40 s), and congo red (150 s)
				High recyclability at least 5 times
Plant	Daphne alpine	V2O5/ZrO2	Surface area of 214 m2/g, particle size of 41.74 nm, band gap 3.93 eV	The degradation efficiencies of V2O5/ZrO2 against methyl orange (76.9%) and picloram (86%) for 75 min	Rasheed et al. (2020)
			Thermal stability up to 1000 °C
Plant	Ageratum conyzoides	Ag/ZrO2	Particle size of 50 nm	The reduction of 2,4-dinitrophenylhydrazine, 4-nitrophenol, nigrosin and congo red	Maham et al. (2020)
			Face centered cubic of Ag on ZrO2 surface	High catalytic performance for reduction of 4-NP into 4-AP (100%) for 6 min, and 2,4-DAPH for 50 s
				At least 5 cycles for reusability study
Plant	Aloe Vera	Mg-doped ZrO2	Shape: hollow microspheres, and tetragonal phase	ZrO2–Mg (2 mol.%) gave the highest degradation efficiency (93%)	Renuka et al. (2016)
				Total organic carbon test gave the mineralization rate of 79% after 60 min of reaction
				Five consecutive cycle runs