Photocatalytic reduction of Cr(VI) over TiO2-coated cellulose acetate monolithic structures using solar light

Marinho, Belisa A.; Cristóvão, Raquel O.; Djellabi, Ridha; Loureiro, José M.; Boaventura, Rui A.R.; Vilar, Vítor J.P.

doi:10.1016/j.apcatb.2016.09.061

Cited by 195 publications

(47 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

Section: Substitutes Of Formatesupporting

confidence: 81%

“…By contrast, while UV/BiOCl-HAP SM /acetate presented a much poorer performance than that of UV/BiOCl-HAP SM /formate. This result is analogous to the finding of Marinho et al [44], who reported citrate significantly promoting the photoreduction of Cr(VI) by TiO 2 /UVA-vis. The enhancement of photocatalytic reduction incited by organic hole scavengers mainly depends on the following three aspects [45]: (I) adsorption capacity of hole scavengers onto the photocatalyst surface; (II) reduction potential of the formed reducing radical ( CO • , HCOO • , CH CH OH , and CH OH ); and (III) accumulation of intermediate products that consume the photogenerated active species (e.g., h + , e , and HO·) but do not produce reducing radicals.…”

Section: Substitutes Of Formatesupporting

confidence: 81%

See 1 more Smart Citation

Treatment of Aqueous Bromate by Superparamagnetic BiOCl-Mediated Advanced Reduction Process

et al. 2017

View full text Add to dashboard Cite

Bromate (BrO − 3 ) contamination in drinking water is a growing concern. Advanced reduction processes (ARPs) are reportedly promising in relieving this concern. In this work, UV/superparamagnetic BiOCl (BiOCl loaded onto superparamagnetic hydroxyapatite) assisted with small molecule carboxylic acid (formate, citrate, and acetate), a carboxyl anion radical (CO •−2 )-based ARP, was proposed to eliminate aqueous BrO − 3 . Formate and citrate were found to be ideal CO•− 2 precursor, and the latter was found to be safe for practical use. BrO − 3 (10 µg·L −1 , WHO guideline for drinking water) can be completely degraded within 3 min under oxygen-free conditions. In this process, BrO − 3 degradation was realized by the reduction of CO •− 2 (major role) and formyloxyl radical (minor role) in bulk solution. The formation mechanism of radicals and the transformation pathway of BrO − 3 were proposed based on data on electron paramagnetic resonance monitoring, competitive kinetics, and degradation product analysis. The process provided a sustainable decontamination performance (<5% deterioration for 10 cycles) and appeared to be more resistant to common electron acceptors (O 2 , NO − 3 , and Fe 3+ ) than hydrated electron based-ARPs. Phosphate based-superparamagnetic hydroxyapatite, used to support BiOCl in this work, was believed to be applicable for resolving the recycling problem of other metal-containing catalyst.

show abstract

Section: Substitutes Of Formatesupporting

confidence: 81%

Section: Substitutes Of Formatesupporting

confidence: 81%

Treatment of Aqueous Bromate by Superparamagnetic BiOCl-Mediated Advanced Reduction Process

et al. 2017

View full text Add to dashboard Cite

show abstract

“…Semiconductor photocatalysis has been shown in recent years to be effective in water purification . Photo‐oxidation of organic contamination, photo‐oxidation or reduction of toxic metal ions to less toxic oxidation states and the production of radicals that are highly effective in destroying bacteria have all been demonstrated by using a variety of different semiconductors over recent years . To date, the most studied semiconductor for this purpose is titanium dioxide (TiO 2 ), which has gained much success owing to its low cost, low toxicity and high stability.…”

Section: Introductionmentioning

confidence: 99%

Improving Carbon‐Coated TiO₂ Films with a TiCl₄ Treatment for Photocatalytic Water Purification

et al. 2017

View full text Add to dashboard Cite

By using a simple thermal decomposition route, carbon‐TiO2 hybrid films have been synthesized from a catechol‐TiO2 surface complex. The coated films display enhanced visible region absorption, owing to the thin (≈2 nm) layer of carbon encapsulating the TiO2. Although photocatalytically active under visible light alone, it is demonstrated that the activity of the carbon‐coated films can be improved further by a hydrolytic treatment with TiCl4, leading to the introduction of small TiO2 particles (5–10 nm) and doping of chlorine into the structure. The combination of the carbon layer and TiCl4 treatment gives increased photocatalytic performance for the photodegradation of dyes, phenolic pollutants and the reduction of toxic CrVI to relatively benign CrIII. In addition, the carbon‐coated films show improved bactericidal activity under UV irradiation, and hence have been successfully tested against the most common types of pollutant present in potential drinking waters.

show abstract

“…Tremendous amounts of research have been conducted to pursue effective methods for the reduction of Cr(VI) to Cr(III) [10,11]. Among various pioneering studies, such as electroreduction [12], chemical reduction [13,14], and microbial reduction [15,16], photocatalytic reduction using semiconductor has recently received increasing attention due to its low cost, high performance and environmental friendliness [17][18][19]. The reduction potential for Cr(VI)/Cr(III) with respect to normal hydrogen electrode (NHE) is 1.33 V. If the conduction band (CB) edge of the semiconductor oxides is above 1.33 V, the electrons photogenerated under illumination can photocatalytically reduce Cr(VI) to Cr(III) in the solution.…”

Section: Introductionmentioning

confidence: 99%

Multicycle photocatalytic reduction of Cr(VI) over transparent PVA/TiO2 nanocomposite films under visible light

et al. 2017

View full text Add to dashboard Cite

Photocatalytic reduction of hexavalent chromium in wastewater has been widely investigated as an attractive treatment method. In this work, we reported an efficient method for photocatalytic reduction of Cr(VI) over transparent polyvinyl alcohol/titanium dioxide (PVA/TiO2) nanocomposite films under sunlight irradiation. The transparent PVA/TiO2 nanocomposite films were prepared by a simple hydrothermal method combined with a solution casting process. The results revealed that the anatase TiO2 nanoparticles with size less than 10 nm were in-situ generated in PVA matrix, which endowed the films with high transparency. Photocatalytic reduction of Cr(VI) over PVA/TiO2 nanocomposite films exhibited superior visible light photocatalytic activity. Mechanism investigation demonstrated that the PVA acted not only as a transparent support for TiO2 nanoparticles, but also as holes scavengers simultaneously to improve the separation of photogenerated holes and electrons. Meanwhile, the transparent PVA/TiO2 nanocomposite films displayed remarkable stability and excellent recyclability during multicycle Cr(VI) photoreduction. Furthermore, the PVA/TiO2 nanocomposite films showed selective adsorption ability for Cr(III), and thus totally removal of Cr(VI) was achieved after photoreduction process.

show abstract

Photocatalytic reduction of Cr(VI) over TiO2-coated cellulose acetate monolithic structures using solar light

Cited by 195 publications

References 44 publications

Treatment of Aqueous Bromate by Superparamagnetic BiOCl-Mediated Advanced Reduction Process

Treatment of Aqueous Bromate by Superparamagnetic BiOCl-Mediated Advanced Reduction Process

Improving Carbon‐Coated TiO₂ Films with a TiCl₄ Treatment for Photocatalytic Water Purification

Multicycle photocatalytic reduction of Cr(VI) over transparent PVA/TiO2 nanocomposite films under visible light

Contact Info

Product

Resources

About

Photocatalytic reduction of Cr(VI) over TiO2-coated cellulose acetate monolithic structures using solar light

Cited by 195 publications

References 44 publications

Treatment of Aqueous Bromate by Superparamagnetic BiOCl-Mediated Advanced Reduction Process

Treatment of Aqueous Bromate by Superparamagnetic BiOCl-Mediated Advanced Reduction Process

Improving Carbon‐Coated TiO2 Films with a TiCl4 Treatment for Photocatalytic Water Purification

Multicycle photocatalytic reduction of Cr(VI) over transparent PVA/TiO2 nanocomposite films under visible light

Contact Info

Product

Resources

About

Improving Carbon‐Coated TiO₂ Films with a TiCl₄ Treatment for Photocatalytic Water Purification