Upconversion-Assisted Solar-Driven Hydrogen Evolution in β-SiC via Synergistic Upconversion-Polydopamine Integration...

Area of Science:

• Materials Science
• Photocatalysis
• Renewable Energy

Background:

• Conventional photocatalysts like TiO2 and SiC struggle to absorb sub-band gap photons, limiting solar energy conversion efficiency for hydrogen production.
• Developing efficient photocatalysts that utilize a broader solar spectrum is crucial for advancing solar fuel generation.

Purpose of the Study:

• To engineer an efficient photocatalyst for enhanced solar hydrogen production by addressing the limited light absorption of conventional materials.
• To synthesize and characterize a novel composite material integrating upconversion and conductive layers for improved photocatalytic performance.

Main Methods:

• Synthesized YAlO3 doped with Ho3+ and Er3+ as an upconversion material (UC-50).
• Fabricated a composite nanosystem (β-SiC@UC-50) by integrating UC-50 with β-SiC.
• Surface-functionalized the composite with a polydopamine (PDA) layer to form β-SiC@UC-50_PDA.
• Evaluated photocatalytic and photoelectrocatalytic performance in a Na2S/Na2SO3 electrolyte under visible light irradiation.

Main Results:

• The β-SiC@UC-50_PDA composite exhibited a 4.6-fold increase in hydrogen production compared to pristine β-SiC under visible light.
• The material demonstrated excellent stability and achieved an apparent quantum efficiency of 11.53% at 650 nm.
• Transient photocurrent measurements showed a 2.9-fold increase, indicating enhanced charge separation and electron transport.

Conclusions:

• The synergistic combination of upconversion material, β-SiC, and PDA significantly enhances photocatalytic hydrogen production.
• The developed β-SiC@UC-50_PDA system offers a promising strategy for efficient solar energy conversion and hydrogen generation.
• Integrated thermoelectric harvesting further improved overall energy utilization, showcasing a multifunctional approach.