Scientists in India turn sunlight into fuel - Green hydrogen tech could power homes, cars

New Delhi: In a development that could significantly advance India’s green hydrogen ambitions, scientists at the Centre for Nano and Soft Matter Sciences (CeNS), Bengaluru, have designed and tested a next-generation device that produces green hydrogen by directly splitting water molecules using sunlight and earth-abundant materials.Unlike the conventional route—where solar panels generate electricity that powers an electrolyser to split water—this new system uses a direct photoelectrochemical (PEC) process. Here, sunlight itself triggers the water-splitting reaction, eliminating the need for an external power supply or fossil-fuel-based backup. This makes the process simpler, more efficient, and potentially cheaper.The research, led by Dr Ashutosh K. Singh and his team at CeNS—an autonomous institute under the Department of Science and Technology (DST)—focuses on building a sustainable and scalable system for green hydrogen generation. The work has been published in the Journal of Materials Chemistry A by the Royal Society of Chemistry.At the core of the innovation is a novel silicon-based photoanode featuring an n-i-p heterojunction architecture. This includes layers of n-type titanium dioxide (TiO₂), intrinsic silicon (Si), and p-type nickel oxide (NiO). The structure enhances light absorption, improves charge separation, and ensures efficient charge transport—critical for direct solar-to-hydrogen conversion.The materials were deposited using magnetron sputtering, a commercial-scale thin-film technique known for precision layering and structural stability. The device operated in alkaline electrolyte conditions and maintained structural integrity over extended hours of use.The prototype achieved a surface photovoltage of 600 millivolts and a low onset potential of 0.11 volts versus the reversible hydrogen electrode (VRHE), indicating high photoelectrochemical efficiency and a low energy threshold. It ran continuously for over 10 hours under simulated solar irradiation with only a 4% drop in performance.“The heterostructure was specifically designed to maximise PEC efficiency while maintaining long-term stability,” said Dr Singh. “This brings us closer to building practical, fossil-fuel-free hydrogen systems.”To demonstrate scalability, the team tested a 25 cm² photoanode, which performed effectively under solar water-splitting conditions. This scale-up shows promise for moving from lab to pilot applications and potentially to commercial hydrogen production.The device’s design avoids rare-earth or high-cost catalysts, does not require high pressure or temperature, and is compatible with different lithium-ion battery chemistries for renewable storage integration—making it flexible and economically viable.The innovation supports India’s clean energy goals under the National Green Hydrogen Mission and Aatmanirbhar Bharat. By producing green hydrogen directly from sunlight without relying on electricity or imported materials, the device contributes to energy self-reliance and carbon-neutral fuel alternatives for mobility, power generation, and industry.According to the DST, such breakthroughs can accelerate India’s leadership in solar hydrogen technology and help build decentralised hydrogen hubs with localised energy ecosystems.The CeNS team is exploring further scale-up pathways, industry partnerships, and integration into existing hydrogen infrastructure. They also plan to test the device in varied climatic conditions to assess long-term field performance across India.If successful, the technology could help build round-the-clock renewable energy systems, especially in sectors where direct electrification is difficult—offering a new route to affordable and indigenous green hydrogen at scale.

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