Optimal Mn doping for enhanced photothermal conversion performance in Prussian blue@layered double hydroxides.

Area of Science:

• Materials Science
• Nanotechnology
• Renewable Energy

Background:

• Near-infrared (NIR)-responsive photothermal materials are crucial for solar energy conversion.
• Conventional materials often suffer from low efficiency, poor stability, and limited spectral tunability.
• There is a need for advanced photothermal materials with improved performance and durability.

Purpose of the Study:

• To synthesize and characterize manganese-doped Prussian blue intercalated MgAl-layered double hydroxides (Mn-PB@LDHs).
• To investigate the synergistic effects of Mn-doping and LDH host on photothermal performance and stability.
• To establish a generalizable host-guest strategy for advanced solar energy materials.

Main Methods:

• Synthesis of Mn-PB@LDHs using a separate nucleation and aging steps (SNAS) method.
• Optimization of Mn doping concentration to balance electronic structure and prevent degradation.
• Characterization of photothermal conversion efficiency and solar-driven water evaporation performance.

Main Results:

• Optimized Mn-PB@LDH-3 achieved a high photothermal conversion efficiency of 75.10% (808 nm laser) and solar water evaporation of 1.60 kg m^-2 h^-1.
• Moderate Mn²⁺ doping enhanced metal-to-metal charge transfer and reduced resistance in Prussian blue.
• The MgAl-LDH host provided stability through nanoconfinement and electrostatic interactions, preventing degradation and leaching.

Conclusions:

• Mn-PB@LDHs represent a high-performance, stable photothermal material for solar energy conversion.
• The study demonstrates the effectiveness of a host-guest strategy for designing advanced energy materials.
• This approach offers a pathway for developing efficient and durable materials for solar fuel applications.