Indian scientists for the first time have developed a large-scale reactor that produces a substantial amount of hydrogen using sustainable sources like sunlight and water, in a cost-effective and sustainable process.

India has set a target of 450 GW of renewable energy by 2030. To achieve this, researchers are working towards renewable energy solutions, which should be sustainable with a limited carbon footprint.

One of the most economical ways to achieve this is to produce hydrogen on a large scale through photocatalytic water splitting. It is a long-term persistent solution for growing renewable energy needs and a low-cost economic process, which will benefit society in the longer term, a Science and Technology Ministry release said.

The work has been done by Dr Kamalakannan Kailasam and his team, including Professor Ashok K. Ganguli, Dr Vivek Bagchi, Dr Sanyasinaidu Boddu, Dr Prakash P.N., and Dr Menaka Jha from the Institute of Nano Science and Technology (INST), Mohali, an autonomous institute under the ministry.

They have developed a prototype reactor that operates under natural sunlight to produce hydrogen at a larger scale (around 6.1 L in eight hours). They have used earth-abundant chemical, carbon nitrides, as a catalyst for the purpose, the release said.

The process had been attempted many times by many researchers using complex metal oxide/nitride/sulphide-based heterogeneous systems but was very difficult to reproduce in large quantities.

“The INST team employed the low-cost organic semiconductor in carbon nitrides, which can be prepared using cheaper precursors like urea and melamine at ease in a kilogram scale,” the release said.

This work is supported by the DST Nano Mission NATDP project. A paper about this work has been published in the ‘Journal of Cleaner Production’ recently, and the team is in the process of obtaining a patent for the technology, the release said.

“The stability and chemical flexibility of having different organic groups in carbon nitrides triggered us to work on these cost-effective organic semiconductor materials for sustainable hydrogen production,” Kamalakannan said.

The INST team started from the lab-scale process to the bulk scale of developing the photocatalyst and hydrogen production through a large prototype reactor.

The reactor is about 1-metre square, and the photocatalyst was coated in the form of panels, where water flow is maintained. Upon natural sunlight irradiation, hydrogen production occurs and is quantified through gas chromatography. The team is in the process of optimising the hydrogen production with effective sunlight hours in addition to the purity of the hydrogen, and so on, to hyphenate with the fuel cells.

Hydrogen generated in this manner can be used in many forms like electricity generation through fuel cells in remote tribal areas, hydrogen stoves, and powering small gadgets, to mention a few. Eventually, it can power transformers and e-vehicles, which are long-term research goals under progress.

India has recently launched a Hydrogen Mission and aims to not just fulfil its own requirement but also export it in near future.