Table 1.

Summary of surface morphology and mineralogy of anodised titanium produced from different electrolytes.

Electrolyte composition	Surface morphology (pore diameter)	XRD detected phase(s)	Ref.
Sulphuric acid	Open pores (0.1–0.5 μm)	Ti, anatase, rutile	[143, 173, 198]
Acetic acid	Pores with small white substrates (1 μm)	Ti, anatase	[199]
Phosphoric acid	Open pores (0.3–1 μm) and flowery pattern	Ti, anatase	[200, 201, 202, 203]
Hydrochloric acid	Open pores (10 μm)	Ti, anatase, rutile	[204]
Sodium sulphate	Gel-like pore structure	Ti, anatase, rutile	[72, 143, 205]
Sodium hydroxide	Nanorod, nanowire, nanoleaf, and nanoflower porous structure	Ti	[193, 206, 207]
Potassium hydroxide	Open pores (150 nm)	Ti	[207, 208]
Sulphuric acid + Phosphoric acid	Open pores (0.5–1.6 μm)	Ti, anatase, rutile	[138, 171, 209]
Potassium hydroxide + Potassium silicate	Large open pores (5–6 μm)	Ti, anatase	[210]
Chromic acid + hydrogen fluorine	Rose-like irregular pore	Ti, anatase	[142]
Sodium hydroxide + Na-tartrate + EDTA + Sodium silicate	Open pores (1 μm)	Ti, anatase, rutile	[211]
Tetraborate electrolytes; lithium, sodium and potassium tetraborate	Cortex-like structure	Ti, anatase, rutile, amorphous B2O3	[91]
Ca-P based electrolyte
•calcium acetate + calcium glycerophosphate or β- glycerophosphate	Donut-shape pore (1 μm)	Ti, anatase, rutile, Ca2Ti5O12, β-Ca2P2O7, α-Ca3(PO4)2, CaTiO3	[66, 139, 142, 174, 177, 182, 192, 212, 213, 214, 215]
•calcium acetate + β- glycerophosphate + sodium hydroxide	Nanoflower-like structure	Ti, anatase, rutile, Na2Ti3O7	[43]
•calcium acetate + β- glycerophosphate + sulphuric acid	Need-like structure	Ti, anatase, rutile, HAp	[216]
•calcium acetate + monosodiumorthophosphate	Petaling-like structure	Ti, anatase, rutile, HAp	[40]
Fluorine based electrolyte
•NH4F + NaCl			[148]
•H2O + glycerol + NH4F			[14, 217, 218, 219, 220, 221, 222]
•H3PO4 + NaF			[223, 224]
•NaF			[160]
•Na2SO4 + NaF			[158]
•H2SO4 + NaF			[180]
•H3PO4 + HF			[225]
•H3PO4 + NH4F			[226]
•Glycerol + H3PO4 + HF	Nanotubes, TNTs	Ti	[162]
Non-fluorine based electrolyte
•NaClO4 + NaCl + H2O + C2H5OH			[123]
•NaCl + H2O + glycerol			[124]
•KBr + H2O + glycerol			[112]
•HClO4 + NaClO4			[112]