Surface defects induced charge imbalance for boosting charge separation and solar-driven photocatalytic hydrogen...

Area of Science:

• Materials Science
• Photocatalysis
• Surface Chemistry

Background:

• Low charge separation efficiency hinders semiconductor photocatalyst performance.
• Developing strategies to improve charge separation is crucial for high-performance photocatalysts.

Purpose of the Study:

• To engineer surface defects in uniform mesoporous TiO2 nanospheres (DMTNSs) to enhance charge separation.
• To investigate the role of surface defects and induced charge imbalance in improving photocatalytic activity.

Main Methods:

• Surfactant-mediated self-assembly solvothermal synthesis of mesoporous TiO2 nanospheres.
• Hydrogenation strategy to introduce surface defects.
• Experimental characterization and density functional theory (DFT) calculations to confirm charge imbalance and built-in field formation.

Main Results:

• Engineered surface defects in DMTNSs created a built-in field, promoting efficient photogenerated charge separation.
• DMTNSs exhibited a photocatalytic hydrogen evolution rate of ~3.34 mmol h⁻¹ g⁻¹, 3.5 times higher than pristine TiO2.
• Defect engineering narrowed the bandgap to ~3.01 eV, extending visible-light response.

Conclusions:

• Surface defect engineering and induced charge imbalance is an effective strategy to boost photocatalytic performance.
• This approach offers a new perspective for fabricating high-efficiency oxide photocatalysts.
• The developed DMTNSs show significant potential for applications in hydrogen production.