Research published in Small journal shows 51% improvement in hydrogen output through solar-water splitting technology
Researchers at the Indian Institute of Technology (IIT) Guwahati have developed a composite coating technology aimed at improving the efficiency and durability of solar-driven water splitting systems for green hydrogen production. The research, published in the international journal Small, demonstrates a significant improvement in hydrogen and oxygen production efficiency compared to conventional methods.
The innovation addresses long-standing technical barriers in the Photo-Assisted Electrochemical (PAEC) process, which is considered one of the most advanced technologies for green hydrogen generation. The findings are expected to have implications for India’s renewable energy targets and global efforts towards achieving carbon neutrality.
Key Technical Challenge
Green hydrogen production through solar water splitting relies on splitting water molecules into hydrogen and oxygen using sunlight. However, the process faces two critical limitations. Catalyst layers physically deposited on electrode surfaces gradually peel off over time, reducing system durability and efficiency. Additionally, gas bubbles adhering to electrodes during reactions block active catalytic sites, thereby reducing hydrogen and oxygen production efficiency.
The research team, led by Prof. Uttam Manna and Prof. Mohammad Qureshi of the Department of Chemistry, designed a solution by embedding graphitic carbon nitride — a two-dimensional photocatalyst — within a bubble-repellent hydrogel layer on porous nickel foam substrate. This approach differs from conventional methods that apply photocatalysts as surface layers.
“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,” Prof. Manna said.
Performance Metrics
When compared to conventional systems using directly coated photocatalysts with or without separate bubble-repellent layers, the developed composite coating achieved 51 per cent higher hydrogen production and 44 per cent higher oxygen production.
The improved performance results from two factors: the internal embedding of the photocatalyst protects it from delamination while creating a larger electrochemically active surface area. Simultaneously, the bubble-repellent matrix enhances the frequency at which gas bubbles depart from electrode surfaces, thereby maintaining unobstructed access to catalytic sites.
Research Team and Funding
The research was conducted by a team comprising Dr. Hrisikesh Sarma and research scholars Ms. Alpana Sahu, Ms. Anshika Chaudhary, Mr. Sumanta Sarkar, Mr. Sourav Mandal, and Mr. Lingaraj Sahoo, all from IIT Guwahati. The work received grant support from the ANRF, the Ministry of Electronics and Information Technology, the Indian Institute of Technology Guwahati, and the Ministry of Education.
Broader Applications
The developed coating strategy has potential applications beyond green hydrogen production. It may benefit renewable energy storage technologies and large-scale solar-to-fuel conversion devices — areas of significance for India’s renewable energy sector.
Prof. Qureshi outlined the next phase of research: “We plan to extend this composite coating approach with tweaks at replacing hydrogels with 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.”
The transition from laboratory demonstration to large-scale industrial application remains a key challenge. The research team will need to validate the technology’s performance on industrial-scale electrodes and demonstrate its integration into practical hydrogen production systems.
Strategic Significance
India has been pursuing green hydrogen as part of its broader clean energy strategy. The National Green Hydrogen Mission, launched in 2023, aims to position India as a hub for green hydrogen production and export. Technologies that improve the efficiency and durability of solar-driven water-splitting systems could contribute to these objectives.
The research also reflects IIT Guwahati’s positioning in clean energy innovation. The institute holds an 8th rank among India’s best engineering institutions and secured rank 87 globally in the SDG 9 category (Industry, Innovation, and Infrastructure) in the Times Higher Education Impact Rankings 2024.
Study Limitations
The research team has clarified that the study is at a laboratory stage and the findings are subject to further validation. “The findings should not be interpreted as final or ready for commercial application,” researchers stated in their disclaimer.
The authors acknowledged Prof. P. K. Iyer and Mr. Himangshu Baishya for technical support in AFM and photoluminescence characterisation studies.
-Rashmi Kumari
