A one-pot synthesis of a monolithic Cu 2 O/Cu catalyst for efficient ozone decomposition.

Nowadays, it is necessary and challenging to prepare monolithic catalysts, which are ready for use, preventing the tedious and complicated integration procedure of the powder materials onto a porous substrate. Herein, Cu 2 O nanoparticles are successfully synthesized onto a porous Cu foam in one pot via the surface oxidation, coordination and precipitation reactions in a NH 4 OH and HCl solution, and the optimum synthesis conditions are a NH 3  : HCl ratio of 1 : 0.9, oxidation temperature of 80 °C and time of 18 h. The obtained Cu 2 O/Cu catalyst (mostly <100 nm) shows a highly active O 3 decomposition performance with >98% and >80% conversion efficiency in dry and 90% relative humidity air for >10 h at an O 3 concentration of 20 ppm and a gas hourly space velocity of 12 500 h -1 . The high efficiency can be attributed to the porous Cu foam providing a large contact area, abundant crystal defects in the nanometer-sized Cu 2 O materials serving as the active sites, and also to the Schottky barrier formed in the Cu 2 O/Cu interface facilitating the electron transfer for O 3 degradation. All these results show the potency of the easily fabricated monolithic Cu 2 O/Cu catalyst for the highly efficient O 3 contaminant removal.