Novel facet-engineered multi-doped TiO2 mesocrystals with unprecedented visible light photocatalytic hydrogen production

We report on the facile synthesis of anatase multi-doped TiO2 mesocrystals with highly energetic {001} facets and their outstanding photocatalytic activity. The structural and compositional properties were investigated via different techniques such as XRD, XPS, Raman photoluminescence, and electron paramagnetic resonance, which confirmed the fabrication of C, Co, and Ti3+-doped anatase single crystal-like mesocrystals. The Mott-Schottky analysis showed a drastic increase in the carrier density upon cobalt doping, resulting in a 6-fold increase in the photoelectrochemical performance compared to the undoped sample. Besides, the photocatalytic efficiency of the as-fabricated mesocrystals in the photochemical production of hydrogen was estimated under AM1.5 conditions without using any hole scavengers. The Co-doped C/Ti3+ TiO2 mesocrystals showed an unprecedented hydrogen production rate when compared to the other similar titanium-based mesocrystals. Finally, the unprecedented enhancement of Co-doped C/Ti3+ TiO2 mesocrystals in water splitting makes them promising candidates for various photocatalytic applications

Superior visible light antimicrobial performance of facet engineered cobalt doped TiO2 mesocrystals in pathogenic bacterium and fungi

Pristine and Co-doped TiO2 mesocrystals have been synthesized via a simple sol–gel method and their antimicrobial activity has been investigated. The antimicrobial performance was evaluated in terms of zone of inhibition, minimum inhibitory concentration (MIC), antibiofilm activity, and effect of UV illumination in liquid media. The Co-doped TiO2 mesocrystals showed very promising MIC of 0.390 μg/mL and 0.781 μg/mL for P. mirabilis and P. mirabilis, respectively. Additionally, the material showed an MIC of 12.5 μg/mL against C. albicans, suggesting its use as antifungal agent. Upon the addition of 10.0 µg/mL of Co-doped TiO2 mesocrystals, the biofilm inhibition% reaches 84.43% for P. aeruginosa, 78.58% for P. mirabilis, and 77.81% for S. typhi, which can be ascribed to the created active oxygen species that decompose the tested microbial cells upon illumination. Thus the fabricated Co-doped TiO2 mesocrystals exhibit sufficient antimicrobial features under visible light, qualifying them for use as antimicrobial agents against pathogenic bacteria and fungi and subsequently inhibit their hazardous effects