An Important Factor Affecting the Supercapacitive Properties of Hydrogenated TiO2 Nanotube Arrays: Crystal Structure

Table 2 Preparation parameters of samples

Samples			H@TNAs-1	H@TNAs-2	H@TNAs-3	H@TNAs-4
Anodisation	Electrolyte composition	NH₄F (g)	0.3	0.3	0.3	0.3
		H₂O (mL)	2	2	2	2
		Ethylene Glycol (mL)	98	98	98	98
	Applied voltage (V)	First anodisation	50	50	50	50
	Applied voltage (V)	Second anodisation	50	50	50	50
	Processing time (h)	First anodisation	1	1	1	1
	Processing time (h)	Second anodisation	1	1	1	1
Annealing	Heating rate (°C min⁻²)		2	2	2	2
	Temperature (^oC)		450	650	650	650
	Holding time (h)		3	1	2	3
Hydrogenation	Electrolyte		0.5 M Na₂SO₄	0.5 M Na₂SO₄	0.5 M Na₂SO₄	0.5 M Na₂SO₄
	Applied voltage (V)		5	5	5	5
	Processing time (s)		30	30	30	30