A DFT-based study of As₂O₃ adsorption using single and bimetallic atom-doped g-C₃N₄

Area of Science:

• Materials Science
• Environmental Chemistry
• Computational Chemistry

Background:

• Non-precious metal atom-doped graphitic carbon nitride (g-C3N4) shows potential for arsenic removal from coal-fired flue gas.
• The adsorption mechanisms and processes on these materials remain unclear.

Purpose of the Study:

• To systematically investigate arsenic trioxide (As2O3) adsorption on single- and double-transition-metal-loaded g-C3N4.
• To elucidate the adsorption location, structure, energy, and charge density using computational methods.

Main Methods:

• Density Functional Theory (DFT) calculations were employed.
• Systematic investigation of single- and double-transition-metal-loaded g-C3N4.
• Analysis of adsorption energy, structure, and charge density.

Main Results:

• Metal doping significantly enhances As2O3 adsorption capacity on g-C3N4.
• Bimetallic doping (M2/g-C3N4) demonstrates superior adsorption energy compared to monometallic doping (M/g-C3N4) due to synergistic effects.
• Cobalt bimetallic doping (Co2/g-C3N4) exhibited the highest adsorption energy (-565.1 kJ mol-1), significantly outperforming pure and monoatomic Co-doped g-C3N4.

Conclusions:

• Bimetallic doping is a promising strategy for designing high-performance adsorbents for arsenic removal.
• DFT calculations provide atomic-scale insights into adsorption mechanisms, aiding rational adsorbent design.
• Co2/g-C3N4 shows exceptional potential for efficient As2O3 capture from flue gas.