Progress in plasma doping semiconductor photocatalysts for efficient pollutant remediation and hydrogen generation

In recent years, solar energy-driven photocatalysis materials have drawn significant attention to addressing the global energy and environmental crisis. However, many of the semiconductor photocatalysts are unable to absorb the visible light of the solar spectra due to their wide band gap. The incorporation of a foreign element such as a dopant in the lattice of these photocatalysts was shown to reduce their band gap and enhance visible light absorption. The doping of semiconductors can be performed using several techniques such as sol-gel, hydrothermal, solvothermal, and plasma-based doping. However, plasma-based doping has been considered a highly efficient approach due to the reduction of the band gap to a large extent, enhancement of visible light absorption, and remarkable photocatalytic activities under visible light illumination. The plasma-based doping approach offered many advantages such as high reactivity, process simplicity, scalability, energy efficiency, homogeneous doping, no chemical inventory, low pressure, and low-temperature operation, and flexibility of operation under gas and liquid phase media. Further advancement of plasma-based doping can be achieved through more theoretical studies allowing an in-depth understanding of the mechanisms and interactions of the species involved. This will facilitate the synthesis and application of doped photocatalysts in a cost-effective manner. This review surveyed recent advances in a wide range of semiconductor photocatalysts doped with various dopants using plasma treatment. Various plasma methods for doping semiconductor photocatalysts and their fundamental mechanisms were discussed. The performance characteristics of the plasma-doped photo-catalysts were compared to other methods in terms of energy and environmental applications including degra-dation of environmental contaminants and solar fuel production such as hydrogen production from water splitting using visible light-driven solar energy. Finally, potential future research directions were recommended for the applications of the efficient photocatalysts developed by plasma treatment.

Automated summary

In recent years, research on solar energy-driven photocatalysis materials has gained significant attention due to their potential in addressing the global energy and environmental crisis. However, many semiconductor photocatalysts have a wide band gap, limiting their ability to absorb visible light. Incorporating dopants through plasma-based doping is a highly efficient approach to reduce the band gap and enhance visible light absorption. Plasma-based doping offers advantages such as high reactivity, simplicity, scalability, energy efficiency, homogeneous doping, and flexibility in gas and liquid phase operations. This review discusses recent advancements in plasma-doped semiconductor photocatalysts, their fundamental mechanisms, and their performance in energy and environmental applications.