Engineers from the University of New South Wales (UNSW) have created ammonia with an 'artificial leaf' using wastewater via a system based on a traditional silicon solar panel.
Ammonia is an essential component of fertilisers among a large variety of industrial and metallurgical applications but traditional production methods require high emissions and energy inputs.
The UNSW team has managed to produce ammonia from wastewater containing nitrate using a photoelectrocatalytic process involving a nano-structured thin layer of copper and cobalt hydroxide that acts as a catalyst.
Scalable ammonia production system
The project was led by UNSW Scientia Professor Rose Amal, in collaboration with Professor Xiaojing Hao, and findings were published in the Journal of Energy and Environmental Science.
The research team, which includes lead author Chen Han and Discovery Early Career Researcher Award (DECRA) fellow Dr Jian Pan, has produced ammonia sufficient for almost one and a half square metres of cropland from an artificial leaf system requiring just 40 square centimetres of space.
“This system works at ambient conditions and just uses sunlight to produce ammonium from nitrate-containing wastewater, which is an important chemical used in fertiliser,” project lead Professor Amal from the School of Chemical Engineering said.
“We think this new technology could be implemented on a relatively small scale in agricultural locations to produce ammonium onsite, which would decentralise the production process and further reduce CO2 emissions that are associated with the transportation process.”
Seeking industry collaboration
Lead author Chen Han said the catalyst was very efficient, resulting in a highly effective process.
“Our findings provide a clean, efficient and cost-effective solution for utilising solar energy and chemical wastes to produce ammonia and other value-added products,” Han said.
“You do not need a high concentration of ammonia in fertiliser, so we believe the amounts of ammonia we are producing using our system make it a viable application in the real world, although we definitely still have some ways to further improve it.”
The team is calling for potential industry partners to collaborate and develop the technology into a fully viable commercial system.
Industry partners would help us scale up this device, and we definitely would like to utilise a full-scale, traditionally sized solar panel for our application,” Professor Amal said.
“This is important for helping us reach our emissions targets of 2030 and 2040, and ultimately achieving Net Zero by 2050. We want to produce ammonia in a cleaner and greener way that minimises CO2 emissions.”