A research team at Tianjin University, China, has achieved a milestone in solar-powered hydrogen production, developing a semi-transparent photoanode that boosts solar -to-hydrogen (STH) conversion efficiency to a record 5.1 percent.
The breakthrough, published in Nature Communications, offers a promising path to scalable “artificial leaf” technology, Science and Technology Daily reported Tuesday (6/17).
The “artificial leaf” is a silicon-based device that uses solar power to separate hydrogen and oxygen in water, thereby producing hydrogen energy in a clean way.
Led by Wang Tuo, professor of the School of Chemical Engineering and Technology, the research team addressed important limitations in the unbiased solar water splitting system, which produces hydrogen without external electrical voltage.
Their innovative indium sulfide (In₂S₃) photoanode overcomes the conventional trade-off between conductivity and light transparency.
"Our semitransparent design simultaneously accelerates the water oxidation reaction and allows photons to reach the photocatalyst, thereby minimizing energy waste," said Wang, who also serves as corresponding author for the study.
Validated in a standalone system powered entirely by solar energy, the device achieved an STH efficiency of 5.1 percent, surpassing the 5 percent benchmark for conventional systems using silicon photocatalysts with inorganic photoanodes. This marks the highest efficiency reported for such a configuration, Wang said.
This research provides a new solution to two current challenges, namely slow interfacial electron transfer and significant optical loss.
With further optimization, this technology is expected to pave the way for developing cost-effective and durable “artificial leaves.”
