Aqueous miscible organic solvent treated NiTi layered double hydroxide De-NOx photocatalysts

New efficient photocatalysts are required to remediate polluted urban atmospheres. We prepared a series of highly dispersed aqueous miscible organic (AMO) solvent treated NiTi layered double hydroxide (NixTi-AMO-LDHs (x = 2,3)) and studied their performance in the photocatalytic abatement of NOx gases. These photocatalysts can be prepared by a simple and scalable coprecipitation method at room temperature. NixTi-AMO-LDHs (x = 2,3) have been prepared with specific N-2 BET surface areas and pore volumes up to to 492 m(2)g(-1) and 1.37 cm(3) g(-1) respectively. Under sunlight simulation, the De-NOx performance of the conventional LDH and P25 (TiO2) benchmarks were surpassed by 40% and 17% respectively by the NixTi-AMO-LDHs. The NixTi-AMO-LDHs photocatalyst also exhibited outstanding reusability and unusually low release of the toxic NO2. The selectivity for the De-NOx process was investigated by in situ DRIFT measurements, the high surface area and pore volume was observed to play a significant role on the adsorption of the NO2 and N2O4 intermediates. The 2D character of the AMO-LDHs contributed to an enhancement in the production of radical species under illumination and reduction charge carrier recombination.

Automated summary

Newly prepared NixTi-AMO-LDHs photocatalysts showed superior performance in reducing NOx gases under simulated sunlight compared to conventional benchmarks, with exceptional reusability and low toxic NO2 release. The high surface area and pore volume of the catalysts played a significant role in the De-NOx process by facilitating adsorption of NO2 and N2O4 intermediates. The 2D character of the AMO-LDHs contributed to an enhancement in radical species production and reduction of charge carrier recombination under illumination.