Nitrogen-Doped TiO₂ Nanotube Arrays with Enhanced Photoelectrochemical Property

Table 1

Factors and levels for orthogonal experiments.

Factors	Levels
	1	2	3
(𝐴) Electrolyte concentration (𝑀)	0.5	1	1.5
(𝐵) Reaction voltage (𝑉)	1	2	3
(𝐶) Reaction time (ℎ)	1	2	3