• AMO-NiTi Layered Double Hydroxide Nanosheets for Photocatalytic Removal of NOx Pollutant

Nowadays, it is greatly concerning the harmful effects provoked over the environment and citizens by the urban pollution of NOx (NO + NO₂) gases. With the aim to remediate this problem, photocatalytic Layered Double Hydroxides (LDH) have been applied recently to remove these pollutants (De-NOx action) directly from the air. In this work, Ni²⁺Ti⁺⁴ -LDH with the interlayer anion carbonate have been synthesized by the coprecipitation method (NiTi-LDH). In addition to this preparation procedure, a treatment, AMOST (Aqueous Miscible Organic Solvent Treatment) has been applied to the samples in order to increase its surface area and particle dispersion (NiTi-AM samples). Moreover, two Ni/Ti ratios have been prepared to examine its effect on the De-NOx performance. The samples were characterized in order to study its structure, porosity, morphology, and optical properties. The obtained results showed that the NiTi-AM chemical structure did not change after the AMOST, but they showed a high increase of the delamination degree, leading to high specific surface area values. The photocatalytic De-NOx performance increases in those samples with higher amount of Ti (Ni/Ti = 2/1) and those subjected to the AMOST process. This process had more effect on the Ni/Ti = 3/1 ratio samples exhibiting improved photoactivity (≈ 10 %) compared to those samples prepared by conventional method. The enhanced De-NOx performance was associated to the higher number of LDH nanosheets, which increases the number of actives sites accessible to the reactant molecules.