Indium surface gradient doped ZnS for efficient photodegradation under visible-light irradiation

Area of Science:

• Materials Science
• Photocatalysis
• Surface Chemistry

Background:

• Zinc sulfide (ZnS) typically shows limited photocatalytic performance due to its wide bandgap and high charge carrier recombination rates.
• Developing efficient visible-light-driven photocatalysts is crucial for environmental remediation applications.

Purpose of the Study:

• To synthesize indium surface gradient doped ZnS using a chemical vapor strategy.
• To investigate the effect of indium surface doping on the photocatalytic activity of ZnS.
• To explore the potential of surface-doped ZnS for the degradation of organic pollutants under visible light.

Main Methods:

• Synthesis of indium surface gradient doped ZnS via chemical vapor deposition using In2O3 as the evaporation source.
• Characterization of the material's optical and electronic properties.
• Evaluation of photocatalytic activity for levofloxacin degradation under visible light irradiation.

Main Results:

• Indium surface doping shifted the absorption edge of ZnS into the visible-light region by forming impurity levels.
• Surface doping significantly improved carrier separation and transfer efficiency compared to bulk doping.
• The optimal indium surface gradient doped ZnS achieved a levofloxacin degradation rate of ~70% in 1 hour, approximately 3.3 times higher than bulk-doped ZnS.

Conclusions:

• Indium surface gradient doping is an effective strategy to enhance the visible-light photocatalytic activity of ZnS.
• The enhanced performance is attributed to improved light absorption, superior carrier separation, and a more negative conduction band position.
• This study provides a novel perspective for designing advanced surface-doped photocatalysts for environmental applications.