Scientists have synthesized a new composite consisting of synthetic diamond particles coated with a nickel shell. Its high electrocatalytic characteristics make it possible to effectively and safely purify domestic and hospital wastewater from paracetamol, one of the main medical pollutants. The results were published in the journal Diamond and Related Materials.

Paracetamol is recognized as one of the most polluting pharmaceuticals. It can affect human health, cause allergic reactions, and also negatively influence aquatic ecosystems. Therefore, there is a need to purify wastewater from it. It is known that this problem can be solved by the method of electrocatalytic oxidation and decomposition of paracetamol into environmentally friendly compounds.

Scientists from the Federal Research Center "Krasnoyarsk Science Center SB RAS" and Siberian Federal University have synthesized particles of synthetic undoped diamond coated with a nickel shell. In this case, diamond serves as the core, with nickel nanoclusters forming the shell. The size of diamond particles ranges from 120 to 130 nanometers while the thickness of the nickel coating varies from 2 to 30 nanometers.

The researchers have studied the electrochemical behavior of nickel-coated diamond particles in the electrocatalytic oxidation reactions of methanol and paracetamol. The diamond-nickel composite has turned out to exhibit significant electrocatalytic activity, which allows a more complete neutralization of paracetamol to carbon dioxide and water than was previously possible. This allows the developed particles to be used both for wastewater treatment and as anode electrocatalysts for methanol fuel cells.

“We have demonstrated that the obtained highly crystalline dielectric particles of synthetic undoped diamond coated with nickel clusters have greater catalytic activity. Moreover, the material has higher electrocatalytic activity in the reactions of electrochemical oxidation of methanol and paracetamol in an alkaline electrolyte compared to known catalytically active materials. The process of electrocatalytic oxidation of paracetamol on a nickel-diamond electrode will make it possible to achieve a high degree of purification of hospital wastewater from these pollutants and make this process safe. This nickel-diamond composite will also allow the application of this nickel-diamond composite to replace expensive platinum and palladium in fuel cells,” said Grigory Churilov, Doctor of Technical Sciences, Professor, Head of the Laboratory of Analytical Methods for the Study of Matter at the L.V. Kirensky Institute of Physics SB RAS.