Photoelectrochemical Antibacterial Platform Based on Rationally Designed Black TiO_2–x Nanowires for Efficient Inactivation against Bacteria

Abstract

A hyphenated strategy for photoelectrochemical (PEC) disinfection is proposed with rationally designed black TiO2–x as a photoresponsive material. The PEC method, a fusion of electrochemistry and photocatalysis, is an innovative and effective way to improve photocatalytic performance, which imparts certain properties to the photoelectrode and greatly promotes the charge transfer, thus effectively inhibiting the recombination of carriers and greatly promoting the catalytic efficiency. The oxygen vacancy (V o) engineering on TiO2 is conducted to obtain black TiO2–x , which shows a much larger light absorption region in the full solar spectrum than the pristine white TiO2 and presents excellent PEC sterilization performance. The bactericidal efficiency with the PEC method is 10 times higher than that with the photocatalytic method, inactivating 99% of bacteria within a short time of 30 min. In addition, the black titanium oxide nanowires (B-TiO2–x NWs) are grown on flexible carbon cloth (CC) to form a sandwich structural self-cleaning face mask. The bacteria adhering to the surface of the mask will be sterilized quickly and efficiently under the illumination of visible light. The face mask with the characteristics of superior antibacterial effect and long service lifetime will be used for epidemic prevention and reduce the second pollution.

A Review on Nano Ti-Based Oxides for Dark and Photocatalysis: From Photoinduced Processes to Bioimplant Applications

“…Further, amorphous black TiO 2 can also be synthesized and used for photocatalysis [ 201 ], which is important for applications such as for bone implants. Black TiO 2 was shown to exhibit biocompatibility [ 213 ], regenerative properties [ 214 ], photothermal properties [ 213 , 214 , 215 ], and microbicidal action [ 213 , 215 , 216 , 217 ], among others. As such, black TiO 2 shows promise for cancer treatment [ 214 , 215 ], as a bone implant coating, and for disinfection purposes [ 213 , 215 , 216 , 217 ].…”

“…Black TiO 2 was shown to exhibit biocompatibility [ 213 ], regenerative properties [ 214 ], photothermal properties [ 213 , 214 , 215 ], and microbicidal action [ 213 , 215 , 216 , 217 ], among others. As such, black TiO 2 shows promise for cancer treatment [ 214 , 215 ], as a bone implant coating, and for disinfection purposes [ 213 , 215 , 216 , 217 ]. Similar to TiO 2 , the photo(electro)catalytic disinfection with black TiO 2 nanomaterials is also claimed to occur due to ROS, in particular, superoxide and/or hydroxyl radicals [ 216 , 217 ].…”

“…As such, black TiO 2 shows promise for cancer treatment [ 214 , 215 ], as a bone implant coating, and for disinfection purposes [ 213 , 215 , 216 , 217 ]. Similar to TiO 2 , the photo(electro)catalytic disinfection with black TiO 2 nanomaterials is also claimed to occur due to ROS, in particular, superoxide and/or hydroxyl radicals [ 216 , 217 ]. Nevertheless, the biosafety of black TiO 2 needs to be further studied to intensify its application in the biomedical field.…”

A Review on 1‐D Nanomaterials: Scaling‐Up with Gas‐Phase Synthesis

“…Other oxides, as in the case of iron, occur naturally and are stable but occasionally denoted without the À x notation: e. g. hematite (Fe 2 O 3 ) vs. magnetite (Fe 3 O 4 ). Bandgap engineering is also achievable via this method; [166,167] however, fewer degrees of freedom are on offer compared to the addition of a foreign element of choice. Such tuning via oxygen vacancies is done through post-treatment of nanowire materials using reducing environments, as illustrated by a fuel-rich flame in Figure 13d.…”

In Situ Polymerization of Methylene Blue on Bacterial Cellulose for Photodynamic/Photoelectricity Synergistic Inhibition of Bacterial Biofilm Formation

“…By modifying common photosensitizers, this material can produce ROS and emit electrical signals when stimulated by light. This results in a synergistic effect of photodynamic/photoelectric antibacterial activity. , This multipurpose antibacterial platform can eradicate a considerable number of bacteria by producing ROS and also destroy biofilms by electrical stimulation. Therefore, this method ensures long-term ablation of bacterial biofilms …”