Composition-driven morphological evolution of BaTiO₃ nanowires for efficient piezocatalytic hydrogen production

Area of Science:

• Materials Science
• Nanotechnology
• Catalysis

Background:

• Piezocatalysis offers an energy-efficient route for hydrogen production from water.
• Barium titanate (BaTiO3) is a promising piezoelectric material due to its stability and non-toxic nature.
• One-dimensional (1D) nanomaterials are expected to improve water-splitting performance.

Purpose of the Study:

• To synthesize and investigate the piezocatalytic hydrogen evolution reaction (HER) efficiency of barium titanate (BaTiO3) nanowires (NWs).
• To explore the impact of precursor Ba:Ti molar ratios on the morphology, defect chemistry, and HER performance of BaTiO3 NWs.
• To understand the morphological evolution mechanism and its correlation with piezocatalytic activity.

Main Methods:

• Hydrothermal synthesis of BaTiO3 NWs with varying Ba:Ti molar ratios (1:1, 2:1, 4:1).
• Systematic investigation of morphology, defect chemistry, and HER efficiency.
• Analysis of morphological evolution via ion exchange and dissolution-growth processes.

Main Results:

• Morphology, aspect ratio, structural stability, and defect content significantly influence HER efficiency.
• BaTiO3 NWs synthesized with a 2:1 Ba:Ti ratio exhibited high crystallinity, optimal defect concentration, and structural integrity.
• The 2:1 Ba:Ti ratio yielded a record HER efficiency of 149.24 μmol h⁻¹g⁻¹ for nanowire morphologies.
• Post-ultrasonication, BaTiO3 NWs showed photocatalytic activity, with the 1:1 sample degrading 56% of RhB in 2 hours.

Conclusions:

• Synthesis conditions, particularly the Ba:Ti molar ratio, are critical for optimizing BaTiO3 NWs for piezocatalytic water splitting.
• The 2:1 Ba:Ti ratio is optimal for achieving high piezocatalytic activity and structural stability.
• BaTiO3 NWs present potential for both piezocatalytic and photocatalytic applications.