Carboxyltin-Functionalized Tungstobismuthate/TiO₂ Photoanodes for Enhanced Energy Storage Effect in Metal...

Area of Science:

• Materials Science
• Electrochemistry
• Corrosion Science

Background:

• Photoelectrochemical cathodic protection (PECCP) is an emerging eco-friendly anti-corrosion method.
• A key challenge is developing materials for sustained protection under both light and dark conditions.

Purpose of the Study:

• To design and synthesize novel polyoxometalates (POMs) for enhanced PECCP.
• To investigate the performance of these materials for protecting 304 stainless steel (304SS).

Main Methods:

• Synthesis of transition metal and carboxyltin-modified polyoxometalates (Bi-POMs) in aqueous solutions.
• Anchoring Bi-POMs to TiO2 to create photoanodes.
• Evaluation of cathodic polarization and coupled potentials under illumination and in darkness.
• Mechanism exploration using femtosecond transient absorption (fs-TA) and density functional theory (DFT).

Main Results:

• Bi-POM/TiO2 photoanodes achieved significant cathodic polarization (440-465 mV) under illumination.
• Enhanced dark cathodic protection was observed, with coupled potentials significantly lower than TiO2 alone (-197 to -175 mV vs. -97 mV).
• Materials provided stable and sustainable protection for 304SS in seawater under intermittent light.

Conclusions:

• The integration of POMs into PECCP systems offers a novel approach for green metal protection.
• The designed Bi-POMs demonstrate potential for long-term, dual-condition anti-corrosion applications.
• This work provides new insights into developing advanced materials for sustainable corrosion prevention.