Effect of HCO3− concentration in groundwater on TiO2 photocatalytic water purification

Negishi, Nobuaki; Miyazaki, Yukari; Kato, Shigekazu; Yang, Yingjun

doi:10.1016/j.apcatb.2018.10.022

Cited by 43 publications

(25 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In a previous study, we revealed why the photocatalytic activity of TiO 2 does not decrease with increasing aragonite accumulation on its surface 19 . The photocatalytic reaction mainly involves the formation and migration of active species, such as •OH, by UV irradiation of the TiO 2 photocatalyst.…”

Section: Resultsmentioning

confidence: 86%

“…In a previous study, we found that calcium carbonate forms on the surface of TiO 2 photocatalysts during the photocatalysis of calcium bicarbonate in water. Moreover, the calcium carbonate mainly demonstrates the crystallinity of aragonite with nano-to micrometer-sized needles 19 . We expected that these aragonite nanoneedles would continuously kill any bacteria in owing water upon contact through the mechano-bactericidal action associated with their topography.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Aqueous Mechano-Bactericidal Action of Acicular Aragonite Crystals

Negishi

Inaba

Miyazaki

et al. 2021

Preprint

Self Cite

View full text Add to dashboard Cite

Nanoneedle structures on dragonfly and cicada wing surfaces or black silicon nanoneedles demonstrate antibacterial phenomena, namely mechano-bactericidal action. These air-exposed, mechano-bactericidal surfaces serve to destroy adherent bacteria, but their bactericidal action in the water is no precedent to report. Calcium carbonate easily accumulates on surfaces during long-term exposure to hard water. We expect that aragonite nanoneedles, in particular, which grow on TiO2 during the photocatalytic treatment of calcium-rich groundwater, exhibit mechano-bactericidal action against bacteria in water. Here, we show that aragonite nanoneedles are grown on TiO2 ceramics from the calcium bicarbonate in mineral water exhibit mechano-bactericidal action against E. coli K-12 in water. Unmodified, calcite-modified as references and aragonite-modified TiO2 ceramics were exposed to water containing E. coli K-12 (in a petri dish), and their bactericidal action over time was investigated under static and agitated conditions. The surfaces of the materials were observed by scanning electron microscopy, and the live/dead bacterial cells were observed by confocal laser scanning microscopy. Further, the synergistic bactericidal performance achieved by mechano-bactericidal action and photocatalysis was demonstrated. Aragonite itself has a high biological affinity for the human body different from the other whisker-sharpen nano-materials, therefore, the mechano-bactericidal action of acicular aragonite in water is expected to inform the development of safe water purification systems for use in developing countries.

show abstract

Section: Resultsmentioning

confidence: 86%

Section: Introductionmentioning

confidence: 99%

Aqueous Mechano-Bactericidal Action of Acicular Aragonite Crystals

Negishi

Inaba

Miyazaki

et al. 2021

Preprint

Self Cite

View full text Add to dashboard Cite

show abstract

“…Scavenging processes can occur in the presence of species which react with OH radicals without leading to degradation, for example, bicarbonate ions (HCO 3 − ) [78] and chlorides [79] should be removed by a pre-treatment or the AOPs will be compromised. In particular, the interference role of bicarbonate, chloride and dissolved silica anions has been recently studied in depth [80][81][82]. Finally, most existing processes rely on TiO 2 as the catalyst material.…”

Section: Advanced Oxidation Processes and Photocatalysismentioning

confidence: 99%

Solar Concentration for Wastewaters Remediation: A Review of Materials and Technologies

et al. 2018

View full text Add to dashboard Cite

As the effectiveness of conventional wastewater treatment processes is increasingly challenged by the growth of industrial activities, a demand for low-cost and low-impact treatments is emerging. A possible solution is represented by systems coupling solar concentration technology with advanced oxidation processes (AOP). In this paper, a review of solar concentration technologies for wastewater remediation is presented, with a focus on photocatalyst materials used in this specific research context. Recent results, though mostly on model systems, open promising perspectives for the use of concentrated sunlight as the energy source powering AOPs. We identify (i) the development of photocatalyst materials capable of efficiently working with sunlight, and (ii) the transition to real wastewater investigation as the most critical issues to be addressed by research in the field.

show abstract

“…It has been found that photocatalysis is a promising technique for the destruction of dyes using semiconductor catalysts under light irradiation [10]. In addition, as per literature reports, enough research work has also been carried out related to the purification of water by photocatalysis [11]. Various types of photocatalysts such as TiO 2 , ZnO, Al 2 O 3 , WO 3 , Fe 3 O 4 , CeO 2 , and their composites have been used for the degradation of organic pollutants [12].…”

Section: Introductionmentioning

confidence: 99%

Ultrasonic-Assisted Synthesis, Characterization, and Photocatalytic Application of SiO₂@TiO₂ Core-Shell Nanocomposite Particles

Bahadur

Chowdhury

Obaidullah

et al. 2019

Journal of Nanomaterials

View full text Add to dashboard Cite

In this study, we report the synthesis of SiO2@TiO2 core-shell nanocomposite particles by ultrasound irradiation of a mixture of dispersed SiO2 nanoparticles, titanium-tetra-n-butoxide (TBOT), and ammonia in an ethanol-water solution medium. The resulting core-shell nanocomposite particles were characterized by SEM, TEM, FT-IR, XPS, XRF, zeta potential measurements, XRD, and UV-visible spectroscopy. Results showed that TiO2 nanoparticles coated on the surface of SiO2 were 6–10 nm in size and retained an anatase crystalline phase. Zeta potential measurements confirmed that the surface property of the SiO2 changed after TiO2 coating. SiO2@TiO2 core-shell particles demonstrated better decolorization of methylene blue dye compared to commercial TiO2 in aqueous solution under UV light. After treatment, the catalysts were separated with low-speed centrifugation and successfully reused four times without loss of activity. This study may provide some inspiration for the synthesis of other metal oxide-metal oxide core-shell nanocomposite materials through ultrasound irradiation.

show abstract

Effect of HCO3− concentration in groundwater on TiO2 photocatalytic water purification

Cited by 43 publications

References 23 publications

Aqueous Mechano-Bactericidal Action of Acicular Aragonite Crystals

Aqueous Mechano-Bactericidal Action of Acicular Aragonite Crystals

Solar Concentration for Wastewaters Remediation: A Review of Materials and Technologies

Ultrasonic-Assisted Synthesis, Characterization, and Photocatalytic Application of SiO₂@TiO₂ Core-Shell Nanocomposite Particles

Contact Info

Product

Resources

About

Effect of HCO3− concentration in groundwater on TiO2 photocatalytic water purification

Cited by 43 publications

References 23 publications

Aqueous Mechano-Bactericidal Action of Acicular Aragonite Crystals

Aqueous Mechano-Bactericidal Action of Acicular Aragonite Crystals

Solar Concentration for Wastewaters Remediation: A Review of Materials and Technologies

Ultrasonic-Assisted Synthesis, Characterization, and Photocatalytic Application of SiO2@TiO2 Core-Shell Nanocomposite Particles

Contact Info

Product

Resources

About

Ultrasonic-Assisted Synthesis, Characterization, and Photocatalytic Application of SiO₂@TiO₂ Core-Shell Nanocomposite Particles