Bandgap reduction of photocatalytic TiO2 nanotube by Cu doping

Abstract

We performed the electronic structure calculations of Cu-doped TiO2 nanotubes by using density functional theory aided by the Hubbard correction (DFT + U). Relative positions of the sub-bands due to the dopants in the band diagram are examined to see if they are properly located within the redox interval. The doping is found to tune the material to be a possible candidate for the photocatalyst by making the bandgap accommodated within the visible and infrared range of the solar spectrum. Among several possibilities of the dopant positions, we found that only the case with the dopant located at the center of nanotube seems preventing from electron-hole recombinations to achieve desired photocatalytic activity with n-type behavior.

Revealing the true impact of interstitial and substitutional nitrogen doping in TiO2 on photoelectrochemical applications

“…[7][8][9][10] Metal (cationic) and non-metal (anionic) doping of TiO2 has been shown to improve its electronic and optical properties beyond what is attainable by pure TiO2. [11][12][13][14][15][16] Nevertheless, doping can only be effective for better performance if the obtained electronic structure of the semiconductor is adequate for a particular photocatalytic reaction.…”

Growth, physical and electrical characterization of nickel oxide thin films prepared by plasma-enhanced atomic layer deposition using nickelocene and oxygen precursors

“…This could be ascribed to the incremental Ni-Ni component in the NiO film with increasing deposition temperature because metallic Ni doping is likely to generate some additional energy levels in the band gap, resulting in the reduction of the energy associated with the transition from valence band to conduction band. [43][44][45] Table 2 shows comparisons of process parameters and film characteristics of various NiO thin films prepared by different methods. It is found that the sputtering technique generates a much larger RMS roughness (518 nm) than the ALD technique (0.231.25 nm), meanwhile, the former also produces a wider atomic ratio range of Ni:O (0.451.86) than the latter (1.131.29).…”

Photocatalytic Inactivation of Salmonella typhimurium by Floating Carbon-Doped TiO2 Photocatalyst

“…This requirement can be fulfilled by using high-temperature TiO 2 synthesis techniques together with the calcination step. Typical examples of such methods are sol–gel [ 11 ], hydrolysis–precipitation [ 11 ], and solvothermal [ 12 ] techniques. However, these methods are hardly compatible with temperature-sensitive substrates such as polystyrene, polyethylene, and other polymers, whereas magnetron sputtering (MS) is a low-temperature technique that can be used for anatase-phase TiO 2 synthesis at near room temperatures.…”