Enhanced photocatalytic bacterial inactivation of atomic-layer deposited anatase-TiO2 thin films on rutile-TiO2 nanotubes

Abstract

Experimental conditions to fabricate rutile-TiO2 nanotubes coated with a conformal anatase-TiO2 thin layer using ALD were reported. A considerable increase in the photocatalytic activity associated with these surface modifications was also observed.

Standardized Figures of Merit for Proper Benchmarking of Photocatalytic Inactivation of Bacteria Using Thin Films Based on TiO2 Nanostructures

“…In this stage of our study, we calculated the BIPHR values based on the PBIE and the photocatalytic hydroxyl generation efficiency (PHGE) radical generation for two sets of samples fabricated and characterized by us. One set consists of TiO 2 nanotube arrays [ 44 ] whose contact with bacteria and material morphology shows minimal variation, while the other set is composed of thermal grown titanium dioxide thin films where the aforementioned parameters show large variations among samples. [ 34 ]…”

“…The photocatalytic generation of •OH during the pNDA bleaching experiments conducted with the TNT samples ( Figure ) exhibits a comparable performance, where the reaction rate constant k 1 reaches its highest value for the reaction with the A‐UTF/R‐TNT sample. [ 44 ]…”

“…Correlation between PBIE, PHGE, and BIPHR calculated values from the study of photocatalytic activity using TiO 2 nanotube arrays. [ 44 ] The projection on the XY plane represents the correlation between the generation of hydroxyl radicals and antibacterial activity under the same conditions.…”

“…This confirms that the presence of a heterostructure between anatase and rutile phase TiO 2 nanostructures promotes the generation of •OH, leading to an improvement in photocatalytic bacteria inactivation, as widely accepted. [10,44,46,47] However, from the analysis of the correlation between the calculated figures of merit values (Figure 5), a large deviation is observed for the BIPHR value in the amorphous TiO 2 nanotube sample (𝛼-TNT). Given the low generation of hydroxyl radicals (as observed in Figure 4, in addition to the PHGE data), it is not possible to attribute the observed antibacterial activity (Figure 3 and Table 3) to oxidative stress-induced damage.…”

Phenol/Chloroform-Free TiO2-Based miRNA Extraction from Cell Lysate

“…This can be advantageous when we isolate RNA molecules, e.g., from SARS-CoV-2 samples. TiO 2 -based materials are also ideal candidates for the isolation of RNA from infectious agents due to the easy decontamination of TiO 2 surfaces by exposure to UV irradiation [ 26 , 27 ].…”