Doped Nanoparticles

Doped Nanoparticles List

Nanomaterials are one of the most active research fields in modern materials science. Nanoparticles are being widely used in various fields of production and life because of their new characteristics in terms of size, distribution and morphology. Metal oxide nanoparticles as solid substrates have attracted much attention from researchers due to their good body surface area ratio, chemical stability, sensitivity, portability, simple process, and low cost, such as ZnO, WO₃ and other nanoparticles. In order to improve the specific properties of nanoparticles, semiconductor metal oxides are usually doped with precious metals, such as Pt, Au, Ag, and so on. The metal oxide nanoparticles doped with precious metals have greatly improved performance in terms of sensitivity, absorption capacity, conductivity, and conduction band position, which makes the application of doped nanoparticles more extensive.

Figure 1. The application of doped nanoparticles

Applications:

• Photocatalyst: TiO₂ has the advantages of excellent chemical stability, high photocatalytic activity, non-toxic and harmless, etc., and is widely used in photocatalytic degradation of various organic pollutants. However, TiO₂ as a catalyst still has problems such as narrow spectral response and difficulty in recycling, which severely restricts the application of TiO₂ in the treatment of actual printing and dyeing wastewater. TiO₂ doped with noble metal ions such as Ag and Au has higher catalytic activity, can increase the spectral response range, and the preparation method is simple.
• Luminescent materials: Inorganic fluorescent nanoparticles are widely used in the fields of fluorescent lamps, luminescent coatings, and semiconductor lighting. α-Al₂O₃ is often used as a good light-emitting host material because of its high hardness, wear resistance, corrosion resistance, and good insulation. It is usually doped with transition metals or rare earth elements to prepare α-Al₂O₃-based fluorescent doped nanoparticles . The completely dispersed nano-luminescent particles are easy to form a stable colloid in the solvent, so it is easy to obtain a solid fluorescent coating with uniform thickness and concentration in the coating process, and is beneficial to better control the process accuracy and the spatial resolution of the fluorescent material. Therefore, the research on the preparation, structure and luminescence properties of completely dispersed, transition metal or rare earth element doped α-Al₂O₃-based nano-luminescent particles is of great significance.
• Sensor: By doping conductive metal into metal oxide nanoparticles, the sensor can greatly improve its performance in terms of sensitivity, absorption capacity, and conductivity. Especially in terms of gas sensitivity, after platinum and gold doping, a specific target gas of 10-100 ppb can be detected. Tin dioxide (SnO₂) is a typical n-type semiconductor metal oxide with a normal rutile phase structure. Its band gap is ₃.6~4.0 eV and electrical conductivity is greater than 80wt%. It has been studied for use in sensors, solar cells, Transparent conductive electrodes and gas sensors and other fields. Similarly, the gas sensitivity of SnO₂ is usually improved by doping with transition metals such as Fe, Cu, Cr, Ni, and Co.

References

1. M. A. Peche-Herrero, D. Maestre, J. Ramírez-Castellanos, A. Cremades, J. Piqueras and J. M. González-Calbet. The controlled transition-metal doping of SnO₂ nanoparticles with tunable luminescence CrystEngComm, 2014, 16, 2969–2976.
2. Arijita Chakraborty, Gouranga H. Debnath and Prasun Mukherjee. Assessing inter lanthanide photophysical interactions in co-doped titanium dioxide nanoparticles for multiplex assays. RSC Adv., 2017, 7, 40767–40778.