Highly dispersed TiO2 nanocrystals and carbon dots on reduced graphene oxide: Ternary nanocomposites for accelerated photocatalytic water disinfection

Zeng, Xiangkang; Wang, Zhouyou; Meng, Na; McCarthy, David Thomas; Deletić, Ana; Pan, Jia Hong; Zhang, Xiwang

doi:10.1016/j.apcatb.2016.09.014

Cited by 180 publications

(73 citation statements)

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“…The authors have remarked that the presence of glucose also affected the growth of TiO 2 nanocrystals. Because of the abundance of -OH groups, glucose molecules can surround TiO 2 nanocrystals, controlling their increase in size and limiting their aggregation [116].…”

Section: Other C-based Tio 2 Heterostructuresmentioning

confidence: 99%

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Visible-Light-Active TiO2-Based Hybrid Nanocatalysts for Environmental Applications

et al. 2017

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Photocatalytic nanomaterials such as TiO 2 are receiving a great deal of attention owing to their potential applications in environmental remediation. Nonetheless, the low efficiency of this class of materials in the visible range has, so far, hampered their large-scale application. The increasing demand for highly efficient, visible-light-active photocatalysts can be addressed by hybrid nanostructured materials in which two or more units, each characterised by peculiar physical properties, surface chemistry and morphology, are combined together into a single nano-object with unprecedented chemical-physical properties. The present review intends to focus on hybrid nanomaterials, based on TiO 2 nanoparticles able to perform visible-light-driven photocatalytic processes for environmental applications. We give a brief overview of the synthetic approaches recently proposed in the literature to synthesise hybrid nanocrystals and discuss the potential applications of such nanostructures in water remediation, abatement of atmospheric pollutants (including NO x and volatile organic compounds (VOCs)) and their use in self-cleaning surfaces.

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Section: Other C-based Tio 2 Heterostructuresmentioning

confidence: 99%

“…The current challenge is to investigate new photocatalysts based on TiO2 Figure 7. Illustration of the synthesis of a C-dot-TiO 2 -reduced graphene oxide nanocomposite and its application for photocatalytic water disinfection [116]. Copyright 2017, Elsevier.…”

Section: Water Remediationmentioning

confidence: 99%

Visible-Light-Active TiO2-Based Hybrid Nanocatalysts for Environmental Applications

et al. 2017

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“…After 90 minutes, almost complete removal of viable colony forming units (CFU) was observed for the 7× BTO sample, while in the unmodified TiO 2 sample around 40 times the number of CFU remained. It has been proposed that photocatalytic bactericidal activity works by oxidative damage to the cell wall 4,53 and modifications to bacterial DNA 54 by reactive oxygen species reducing the ability of bacteria to form viable colonies. Rapid destruction of E. coli is an encouraging sign of bactericidal activity; however, it should be noted that as a Gramnegative bacteria E. coli is more susceptible to destruction using advanced oxidation processes than Gram-positive bacteria.…”

Section: Bactericidal Testingmentioning

confidence: 99%

“…4,5 For this purpose, titanium dioxide (TiO 2 ) is a material which is subject to considerable attention 6,7 due to the high natural abundance of its constituent elements in the earth's crust, 8 low cost 9 and low toxicity. 10 However, due to the wide band gap of 3-3.2 eV, the use of TiO 2 under solar irradiation is limited to the UV portion of the spectrum (∼5%).…”

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confidence: 99%

Sequential ionic layer adsorption and reaction (SILAR) deposition of Bi₄Ti₃O₁₂ on TiO₂: an enhanced and stable photocatalytic system for water purification

Odling

Chatzisymeon

Robertson

2018

Catal. Sci. Technol.

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A new method to produce bismuth titanate -titanium dioxide composites by modification of a TiO 2 film deposited on a variety of different glass substrates is reported. Using a simple SILAR method, BiOBr may be deposited upon TiO 2 surfaces, which upon heating forms a closely intercalated structure of bismuth titanate (Bi 4 Ti 3 O 12 , BTO) and TiO 2 . This new method expands the scope of the SILAR process, which is typically restricted to materials which can be formed from soluble precursors. This composite material has undergone a thorough materials characterisation to confirm the absence of the BiOBr precursor, and the formation of the new bismuth titanate phase. The electronic structure of the heterojunction formed has also been investigated by valence band XPS and diffuse reflectance measurements, and a plausible band structure proposed. The immobilised composites have then been applied to the photocatalytic degradation of organic pollutants and bactericidal testing, as well as stability tests and identification of the key reactive species. Further photocatalytic studies have been carried out on this material in a synthetic wastewater medium, taking a step towards application under real-world conditions. IntroductionThe availability of clean water has been identified as one of the United Nations' global goals for sustainable development. 1 The provision of this basic resource for a rapidly growing global population poses significant challenges, namely the extreme low cost and lack of extensive infrastructure required to be viable in the developing world. Semiconductor photocatalysis has the potential to fit this niche well, particularly when operated using freely available sunlight. Indeed, it is often the regions of the globe worst affected by poor water quality that have reliable sunshine over much of the year. 2Through the generation of reactive species, semiconductor photocatalysis has been proven to be effective in the destruction of organic pollutants 3 and bacteria. 4,5 For this purpose, titanium dioxide (TiO 2 ) is a material which is subject to considerable attention 6,7 due to the high natural abundance of its constituent elements in the earth's crust, 8 low cost 9 and low toxicity. 10 However, due to the wide band gap of 3-3.2 eV, the use of TiO 2 under solar irradiation is limited to the UV portion of the spectrum (∼5%). In addition, recombination of photo-generated charges has been found to be orders of magnitude faster than surface reactions, 11,12 causing most of the photo-excited holes and electrons to recombine before being able to generate any useful species. One method by which TiO 2 can be given both visible light activity and a mechanism to allow charges to separate is to form a heterojunction with another, narrower band gap semiconductor. 13 The narrower band gap allows excitation by visible light, and the interface between the two materials allows charges to be separated in space and therefore recombination is hindered. method to prepare a titanate semiconductor due to the insolubilit...

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“…Akhavan and colleagues reported the preparation of TiO2/MWCNTs heterojunction arrays for the inactivation of the E. coli bacteria [128]. Several photoinduced mechanisms among these materials have been explained, including the transfer of photogenerated electrons of the irradiated TiO2 to the CQDs (acting as electron acceptors) as well as the direct injection of electrons into conduction band of TiO2 coming from up-conversion and/or down-conversion processes of the CQDs[132,133]. Sangari et al, have also reported the use of multi-walled carbon nanotubesfluorine-co-doped TiO2 (F-doped MWCNTs/TiO2) composites for the removal of grampositive Staphylococcus aureus and gram-negative Pseudomonas aeruginosa [129].Other carbon-based materials, such as carbon quantum dots (CQDs), have also been coupled with TiO2 for the elimination of microorganisms.…”

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confidence: 99%

An approach to the photocatalytic mechanism in the TiO2-nanomaterials microorganism interface for the control of infectious processes

Rodríguez-González

Obregón

Patrón-Soberano

et al. 2020

Applied Catalysis B: Environmental

148

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J o u r n a l P r e -p r o o f 2 Graphical Abstract Highlights  Photoactive TiO2 nanomaterials can solve the actual microbial infectious defies  The microbial cell/TiO2 surface approach is key to get the photo-kill mechanism  Microbial preparation requires a reproducible protocol for proper characterization  Advanced surface characterization techniques can unravel the photo-kill mechanism  Generation of ROS, physical injuries and biocidal features confirm the annihilation J o u r n a l P r e -p r o o f Abstract The approach of this timely review considers the current literature that is focused on the interface nanostructure/cell-wall microorganism to understand the annihilation mechanism. Morphological studies use optical and electronic microscopes to determine the physical damage on the cell-wall and the possible cell lysis that confirms the viability and microorganism death. The key parameters of the tailoring the surface of the photoactive nanostructures such as the metal functionalization with bacteriostatic properties, hydrophilicity, textural porosity, morphology and the formation of heterojunction systems, can achieve the effective eradication of the microorganisms under natural conditions, ranging from practical to applications in environment, agriculture, and so on. However, to our knowledge, a comprehensive review of the microorganism/nanomaterial interface approach has rarely been conducted. The final remarks point the ideal photocatalytic way for the effective prevention/eradication of microorganisms, considering the resistance that the microorganism could develop without the appropriate regulatory aspects for human and ecosystem safety. Introduction and background 1. TiO 2 based materials obtained from TiO 2 and its composites J o u r n a l P r e -p r o o f previous studies have demonstrated that photocatalysis can be considered a promising tool in anticancer therapies, since the photocatalyst can kill cancer cells such as HeLa cells, which cause cervical cancer [7]. The energy absorbed by the photocatalyst comprises the range of ultraviolet and/or visible light, even natural sunlight. When the photocatalyst absorbs light, if the energy of the photons is enough to excite the electrons J o u r n a l P r e -p r o o f 6in the valence band (VB), then they migrate to a higher energy level in the conduction band (CB) of the material, as it is illustrated in Fig. 1. This phenomenon generates the charge carriers known as hole-electron pairs. The photogenerated hole can migrate to the surface of the material and react with water molecules or hydroxyl ions to produce hydroxyl radicals, while the photoexcited electron in the conduction band can react with the adsorbed molecular oxygen to produce superoxide ions [8]. Since the report of Fujishima and Honda about the water splitting process using a TiO2 electrode under UV irradiation, numerous studies have exploited the photoactive properties of this material [9,10]. Several reviews have studied the relationship between the electronic properties of TiO2 with...

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Highly dispersed TiO2 nanocrystals and carbon dots on reduced graphene oxide: Ternary nanocomposites for accelerated photocatalytic water disinfection

Cited by 180 publications

References 50 publications

Visible-Light-Active TiO2-Based Hybrid Nanocatalysts for Environmental Applications

Visible-Light-Active TiO2-Based Hybrid Nanocatalysts for Environmental Applications

Sequential ionic layer adsorption and reaction (SILAR) deposition of Bi₄Ti₃O₁₂ on TiO₂: an enhanced and stable photocatalytic system for water purification

An approach to the photocatalytic mechanism in the TiO2-nanomaterials microorganism interface for the control of infectious processes

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Highly dispersed TiO2 nanocrystals and carbon dots on reduced graphene oxide: Ternary nanocomposites for accelerated photocatalytic water disinfection

Cited by 180 publications

References 50 publications

Visible-Light-Active TiO2-Based Hybrid Nanocatalysts for Environmental Applications

Visible-Light-Active TiO2-Based Hybrid Nanocatalysts for Environmental Applications

Sequential ionic layer adsorption and reaction (SILAR) deposition of Bi4Ti3O12 on TiO2: an enhanced and stable photocatalytic system for water purification

An approach to the photocatalytic mechanism in the TiO2-nanomaterials microorganism interface for the control of infectious processes

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Sequential ionic layer adsorption and reaction (SILAR) deposition of Bi₄Ti₃O₁₂ on TiO₂: an enhanced and stable photocatalytic system for water purification