Preparation and Characterization of Ni-Doped TiO₂ Materials for Photocurrent and Photocatalytic Applications

Table 2

Photoelectrochemical and band-gap energy data of Ni-doped TiO₂ (Ni = 0.1, 0.5, 1, 5, and 10 at. wt.%) powders formed at 550°C for 6 h.^†

Ni (at. wt.%) in TiO2	Zeta potential (mV) at pH~7	pH0[^a]	𝐸bg [eV]^[b]		𝑈fb (versus NHE)^[a] calculated for pH 7 [V]^[c]
			Direct	Indirect
0.1	−21.1 ± 2.22	7.3	3.22	3.08	−0.23
0.5	−21.3±2.68	4.2	2.97	2.92	−0.41
1	−21.8±2.65	4.1	3.10	2.80	−0.42
5	−25.6±2.22	7.3 & 10.3	3.15	2.42 & 2.87	−0.23 & −0.05
10	−28.8±2.40	4.4 & 10.8	3.02	2.37 & 2.87	−0.40 & −0.02

^†The values are arrived as detailed in the experimental section.
^[a]Measured according to [32, 33]. ^[b]These values measured for powders by following DRS spectra, and the reproducibility was better than ±0.01 eV. ^[c]Reproducibility was better than ±0.01 V.