Indian Institute of Technology (IIT) Mandi researchers in collaboration with Yogi Vemana University, Andhra Pradesh have developed new materials that can use sunlight for the production of hydrogen from water.

The research was undertaken by a team lead by Dr Venkata Krishnan, Associate Professor of IIT Mandi with research scholars Suneel Kumar, Ajay Kumar, Ashish Kumar along with Dr MV Shankar and VN Rao of Yogi Vemana University.

The results of their recent study have found a place in the American Chemical Society (ACS) Applied Energy Materials journal.

Talking on the development, Krishnan said with concerns of dwindling fossil fuel reserves and environmental issues associated with their use, there has been an impetus to develop alternative, safe fuels.

“Hydrogen gas, with its high energy yield and eco-friendliness has been identified as a potential energy vector that can herald a new hydrogen-based economy.

The catch with hydrogen economy is that the gas is now largely obtained from fossil fuels by petroleum and natural gas steam reforming processes, which does not help with the problem we set out solving and finding alternatives to fossil fuels.

He said water, the simplest chemical compound known to man, is made of two hydrogen atoms and one oxygen atom and is logically a good source of hydrogen.

However, splitting water into hydrogen and oxygen is not easy and is energy-intensive. It has been known for decades that light can assist in the splitting of water into its constituent hydrogen and oxygen atoms.

“Nature already uses light from the sun to bring about all kinds of chemical conversions that provide us today with the air we breathe and the food we eat.

Mimicking photosynthesis, the use of light for chemical reactions has been one of the Holy Grails of applied chemistry and there has been a constant quest for specialized chemicals, called catalysts that can take the energy of the light to the water to split it, much like the chlorophyll that does it effortlessly in nature.

For a long time, platinum has been used as a catalyst for photochemical water splitting, but given the cost of platinum, solar hydrogen generation has been out of practical reach,” he said.

The researchers have developed a novel multi-component catalyst comprising nitrogen-doped zinc oxide nanorods coated with molybdenum sulphide-nanosheets.

Materials in the nanometre scale, a scale that is a hundred thousand times smaller than the width of a single human hair, have high surface-area-to-volume ratio, improved physical properties and tune-able electronic properties, all of which make them suitable for photocatalytic activities.

“Our work provides the facile strategy for the rational design of efficient and recyclable photocatalysts for solar-to-hydrogen fuel conversion,” he added.