Sunlight to Fuel: Indian Breakthrough in Green Hydrogen Heralds Clean Energy Future

by R. Suryamurthy June 22, 2025

By R. Suryamurthy June 22, 2025 0 comments 3 minutes read

Schematic illustration of the n-i-p heterojunction photoanode showing charge transfer pathways for efficient solar water splitting. Inset images highlight the large-area photoanode (25 cm2) generating hydrogen under solar energy and its surface photovoltage response demonstrating strong photo-electrocatalytic activity and scalability. PHOTO: PIB

Indian scientists have developed a next-generation device capable of producing green hydrogen by splitting water molecules using only solar energy and earth-abundant materials. This innovation holds immense promise for decarbonizing industries, powering vehicles, and efficiently storing renewable energy.

Green hydrogen, long lauded as one of the cleanest fuels, has faced challenges in scalable and affordable production. However, a team of researchers from the Centre for Nano and Soft Matter Sciences (CeNS), Bengaluru, an autonomous institute under the Department of Science and Technology (DST), has achieved a major breakthrough in this area. Their new device eliminates the need for fossil fuels or expensive resources, relying solely on the sun’s power.

Innovative Design and Scalable Production

Led by Dr. Ashutosh K. Singh, the research team engineered a cutting-edge silicon-based photoanode featuring an innovative n-i-p heterojunction architecture. This sophisticated design incorporates stacked layers of n-type titanium dioxide (TiO2), intrinsic (undoped) silicon (Si), and p-type nickel oxide (NiO) semiconductors. These layers work in synergy to enhance charge separation and transport efficiency, crucial for effective solar-to-hydrogen conversion.

The materials were deposited using magnetron sputtering, a highly scalable and industry-ready technique that ensures precision and efficiency in manufacturing. This meticulous engineering approach facilitates superior light absorption, accelerated charge transport, and minimized recombination loss – all vital elements for efficient green hydrogen generation.

Exceptional Performance and Durability

The device’s performance has been nothing short of impressive. It achieved an excellent surface photovoltage of 600 mV and a remarkably low onset potential of around 0.11 VRHE, demonstrating its high effectiveness in generating hydrogen under solar energy.

Furthermore, the device showcased exceptional long-term stability, operating continuously for over 10 hours in harsh alkaline conditions with only a mere 4 per cent drop in performance. This level of durability is a rare feat in silicon-based photoelectrochemical systems, making the technology particularly robust for real-world applications.

Cost-Effective and Scalable Solution

This new device is attractive for several reasons, including its high efficiency, low energy input, robust durability, and the use of cost-effective materials. Importantly, it has already demonstrated successful performance at a larger scale, with a 25 cm² photoanode delivering excellent results in solar water-splitting.

“By selecting smart materials and combining them into a heterostructure, we have created a device that not only boosts performance but can also be produced on a large scale,” said Dr. Singh. “This brings us one step closer to affordable, large-scale solar-to-hydrogen energy systems.”

The groundbreaking work has been published in the prestigious Journal of Materials Chemistry A, published by the Royal Society of Chemistry. Researchers believe this is just the beginning, envisioning a future where this technology could fuel hydrogen-based energy systems, from individual homes to large factories, all powered sustainably by the sun.