Indian Institute of Technology Guwahati researchers have developed a new composite coating technology capable of improving the efficiency and durability of solar-driven water splitting systems used for green hydrogen production.
Published in the prestigious international journal, Small, the findings of this research have been reported in a paper co-authored by Prof. Uttam Manna and Prof. Mohammad Qureshi, along with Dr Hrisikesh Sarma, and research scholars, Alpana Sahu, Anshika Chaudhary, Sumanta Sarkar, Sourav Mandal and Lingaraj Sahoo from IIT Guwahati.
In recent years, green hydrogen has emerged as a significant clean energy source for reducing dependence on fossil fuels.
Conventional hydrogen production methods release large amounts of greenhouse gases as a byproduct.
On the other hand, green hydrogen is generated by splitting water into hydrogen and oxygen using sunlight.
To achieve this, the Photo-Assisted Electrochemical (PAEC) process is considered one of the most advanced technologies. However, the process faces two critical challenges – (a) physically deposited catalyst layers gradually peeling off from electrode surfaces, reducing the system’s durability and efficiency over time and (b) gas bubbles sticking to the electrodes during reactions, resulting in blockage of active catalytic sites and reducing hydrogen and oxygen production efficiency.
To address these limitations, the IIT Guwahati research team designed a durable coating that repels gas bubbles by combining graphitic carbon nitride, a two-dimensional photocatalyst, with a bubble-repellent hydrogel layer on porous nickel foam.
Contrary to conventional methods that apply photocatalysts as surface layers, the research team embedded the photocatalyst inside the coating structure itself. This architecture helped protect the catalyst from delamination and created a larger electrochemically active surface area for water-splitting reactions.
This approach resulted in significantly improved reaction performance compared to conventional systems using directly coated photocatalysts, with or without separate bubble-repellent layers.
In comparison to the convention methods, the developed composite coating achieved 51 percent higher hydrogen production and 44 percent higher oxygen production.
Speaking about the findings of the research, Prof. Uttam Manna, Professor, Department of Chemistry, IIT Guwahati, said, “In this study, we successfully demonstrated the positive impact of incorporating a model two-dimensional catalyst, namely graphitic carbon nitride, within an extremely bubble-repellent matrix to promote bubble departure frequency and enhance photo-assisted electrochemical water-splitting performance. As a result, we observed a significant improvement in hydrogen production. This strategy is broadly applicable, and many other catalysts may be explored in the future to further advance green hydrogen production.”
The developed technology has potential in next-generation clean energy systems, particularly for sustainable green hydrogen production through solar-assisted water splitting. The coating strategy may also benefit renewable energy storage technologies and large-scale solar-to-fuel conversion devices.
Speaking about the next step of the research, Prof. Mohammad Qureshi, Professor, Department of Chemistry, IIT Guwahati, said, “We plan to extend this composite coating approach with a tweak at replacing hydrogels to other advanced photocatalysts to further improve water-splitting efficiency. Future studies will also focus on scaling the system for larger electrodes and integrating it into practical solar hydrogen production devices.”
Conducted with grant support from ANRF, the Ministry of Electronics and Information Technology, Indian Institute of Technology Guwahati, and the Ministry of Education, the study presents an effective strategy for improving the long-term performance of solar-driven water-splitting systems.
IIT-Guwahati achieves major boost in green hydrogen production efficiency through new innovation
