Reported by Roopak Goswami
Guwahati: Researchers at Indian Institute of Technology (IIT) Guwahati have developed a new coating technology that can significantly improve the efficiency and durability of solar-powered green hydrogen production systems — a breakthrough that could support cleaner energy generation in the future.
The study, published in the international journal Small, was led by Prof. Uttam Manna and Prof. Mohammad Qureshi from the Department of Chemistry, IIT Guwahati, along with Hrisikesh Sarma and research scholars Alpana Sahu, Anshika Chaudhary, Sumanta Sarkar, Sourav Mandal and Lingaraj Sahoo.
Green hydrogen is considered one of the cleanest future fuels because it is produced by splitting water into hydrogen and oxygen using sunlight, without releasing greenhouse gases. However, existing solar-driven water-splitting systems face major problems that reduce their long-term efficiency.
One key issue is that catalyst layers coated on electrodes gradually peel off over time, reducing durability. Another challenge comes from gas bubbles sticking to the electrode surface during the reaction, blocking active sites and slowing hydrogen production.
To address these challenges, the IIT Guwahati team created a special composite coating that not only protects the catalyst layer but also repels gas bubbles from the electrode surface.
The researchers combined graphitic carbon nitride — a sunlight-active photocatalyst with a bubble-repellent hydrogel layer on porous nickel foam. Unlike conventional systems, where catalysts are simply coated on the surface, the IIT Guwahati team embedded the catalyst within the coating structure itself.
This helped create a larger active surface area for reactions while preventing the catalyst from peeling away.
Compared to conventional systems, the new coating achieved 51 per cent higher hydrogen production and 44 per cent higher oxygen production.
Explaining the significance of the work, Prof. Uttam Manna said the bubble-repellent coating increased the frequency at which gas bubbles detached from the surface, allowing the water-splitting reaction to continue more efficiently.
“This strategy is broadly applicable, and many other catalysts may be explored in the future to further advance green hydrogen production,” he said.
The technology could have applications in next-generation clean energy systems, renewable energy storage and large-scale solar-to-fuel conversion devices.
Prof. Mohammad Qureshi said the next phase of the research will focus on improving the coating further with advanced photocatalysts and scaling up the system for practical solar hydrogen production devices.
The research was supported by grants from the Anusandhan National Research Foundation, the Ministry of Electronics and Information Technology, IIT Guwahati and the Ministry of Education.
Scientists believe the breakthrough could contribute to global efforts towards carbon neutrality and reducing dependence on fossil fuels.