Effect of Nd3+ doping on the bandgap of TiO2 nanoparticles:
We have assessed the efficacy of several dopants towards the enhancement of the photoactivity of TiO2 nanoparticles towards a specific pollutant. This work will serve as a database for the researchers in this area.
Theoretical modeling of the band gap reduction of TiO2 nanoparticles by Nd3+ doping:
Density functional theory calculations using the generalized gradient approximation with the linearized augmented plane wave method were used to interpret the band gap narrowing. The band gap narrowing was primarily attributed to the substitutional Nd3+ ions which introduced electron states into the band gap of TiO2 to form the new lowest unoccupied molecular orbital. This work helps in understanding how the band gap narrowing occurs in TiO2 nanoparticles and provides a theoretical methodology for other scientists working in this area.
Effect of Nd3+ on the photocatalytic activity of TiO2 nanoparticles:
The results of photodegradation of the pollutant 2-chlorophenol solution irradiated under ultraviolet light showed that 1 at.% of Nd3+ doped TiO2 had an enhanced degradation of the pollutant. The enhancement of photocatalytic efficiency by doped nanoparticles was ascribed to the large surface area and trapping induced prolonged lifetime of holes. Additionally, a new interpretation of the enhancement in the photocatalytic activity, based on the ionic radii of the dopants was given. A larger size Nd3+ in TiO2 nanoparticles causes localized disturbance in the charge distribution at the Ti sites which help in carrier trapping. This is a new interpretation and applicable to all the systems of large band semiconductors and dopants. As such, it will be helpful to the scientists working in this area.
Gas sensing with TiO2:
Although this work is related to the sensors, it shows the effect of decorating the TiO2 nanoparticles by noble metals. This is related to one of our objectives of understanding the effect of Ag, Pd, and Pt decoration on the photocatalytic activity of TiO2 nanoparticles. This gives the researchers in this area another path to modify the photocatalytic behavior of TiO2 nanoparticles.