Submit to Catalysts Review for Catalysts Propose a Special Issue

Journal Menu

Journal Browser

► Journal Browser

Photocatalytic Wastewater Treatment

Special Issue Editors
Special Issue Information
Keywords
Benefits of Publishing in a Special Issue
Published Papers

A special issue of Catalysts (ISSN 2073-4344). This special issue belongs to the section "Photocatalysis".

Deadline for manuscript submissions: closed (15 April 2016) | Viewed by 72035

Share This Special Issue

Special Issue Editors

Prof. Dr. Dionysios (Dion) Demetriou Dionysiou

E-Mail Website
Guest Editor

Environmental Engineering and Science Program, Department of Chemical and Environmental Engineering (ChEE), University of Cincinnati, Cincinnati, OH 45221-0012, USA
Interests: advanced oxidation; advanced reduction; nanotechnology; water treatment; water reuse; water quality; (photo)catalysis; environmental catalysis; environmental sensors; emerging contaminants; cyanotoxins
Special Issues, Collections and Topics in MDPI journals

Dr. Giusy Lofrano

E-Mail Website
Guest Editor

Department of Chemistry and Biology DCB, University of Salerno, Fisciano, Italy
Interests: advanced oxidation processes, water reuse, nanotechnology, wastewater disinfection, antibiotic resistance
Special Issues, Collections and Topics in MDPI journals

Dr. Polycarpos Falaras

E-Mail Website
Guest Editor

Institute Nanoscience and Nanotechnology (INN) National Center for Scientific Research "Demokritos", Agia Paraskevi Attikis, 15341 Athens, Greece
Interests: third-generation photovoltaics, including perovskite, dye-sensitized and quantum dot solar cells
Special Issues, Collections and Topics in MDPI journals

Dr. Suresh C. Pillai

E-Mail
Guest Editor

Centre for Precision Engineering, Materials and Manufacturing Research & Nanotechnology Research Group, Department of Environmental Science, Institute of Technology Sligo, Ash Lane, Sligo, Ireland
Interests: nanotechnology; energy; materials for environment

Dr. Adrián M.T. Silva

E-Mail Website
Guest Editor

Laboratory of Separation and Reaction Engineering - Laboratory of Catalysis and Materials (LSRE-LCM), Faculdade de Engenharia da Universidade do Porto, Rua Dr. Roberto Frias, 4200-465 Porto, Portugal
Interests: water and wastewater treatment, desalination and reuse; advanced oxidation technologies; membrane technology; environmental monitoring
Special Issues, Collections and Topics in MDPI journals

Prof. Dr. Xie Quan

E-Mail Website
Guest Editor

Key Laboratory of Industrial Ecology and Environmental Engineering (MOE), School of Environmental Science and Technology, Dalian University of Technology, Dalian 116024, China
Interests: wastewater treatment; advanced oxidation processes; membrane separation for water treatment; catalysis for environmental applications; functional materials for environmental applications

Special Issue Information

Photocatalytic processes have shown great potential in recent years as environmentally friendly and sustainable treatment technologies to align with the “zero” waste scheme in the wastewater industry. At present, the main technical barriers that prevent their commercialisation remain: a) the costs associated with the UV source capital, b) the post-recovery of the catalysts after water treatment, and c) the efficiency of the photocatalytic treatment process, especially for new emerging/recalcitrant pollutants.

In order to meet and solve these technical challenges, research efforts have been focused on the development of catalysts with a broader range of light absorption for better utilization of sunlight and its integration through nanostructured films on different supports in integrated photocatalytic reactor systems (e.g., membrane-photocatalytic reactors which could combine two treatments, photocatalysis and filtration, in one unit). To date, several methods for achieving visible-light-driven photocatalysis or for increasing the lifetime of the photoproduced electron-hole pairs are widely investigated. These include modification of TiO₂, the most popular photocatalyst, and several other commercially available nanocrystalline semiconductors (e.g., ZnO or CuO) by various metal ions or non-metallic species (N, C, S, B, P, F, or I), as well as by combination of these semiconductors with carbon materials. However, the stability and long-term efficacy of these alternative photocatalysts have not been tested. In terms of integration of these nanostructured photocatalytic films on membranes, research is still in its beginning and a great deal remains to be done. Judicious engineering of the semiconductor nanostructured materials may significantly enhance the development of a green, cost effective, and efficient technology for the removal of contaminants of emerging concern.

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Catalysts is an international peer-reviewed open access monthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2200 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

Synthesis, characterisation and test applications of catalysts in Advanced Oxidation and Reduction Processes (AOPs, AORs) for the removal of emerging contaminants
Applications of photocatalytic processes in disinfection treatments
New generation photocatalysts for decontamination and disinfection applications
Operation mechanism clarification(s)
Process engineering (including modeling) for up-scaling materials and devices (photoreactors)
Green chemistry considerations for the development and application of photocatalytic processes in water and wastewater treatment
Economics of the photocatalytic technologies in water and wastewater remediation
Fate of catalysts in wastewater treatment plants
Challenges around the development of photocatalysis for beneficial ends in water/wastewater treatment

Benefits of Publishing in a Special Issue

Ease of navigation: Grouping papers by topic helps scholars navigate broad scope journals more efficiently.
Greater discoverability: Special Issues support the reach and impact of scientific research. Articles in Special Issues are more discoverable and cited more frequently.
Expansion of research network: Special Issues facilitate connections among authors, fostering scientific collaborations.
External promotion: Articles in Special Issues are often promoted through the journal's social media, increasing their visibility.
e-Book format: Special Issues with more than 10 articles can be published as dedicated e-books, ensuring wide and rapid dissemination.

Further information on MDPI's Special Issue polices can be found here.

Published Papers (9 papers)

Download All Papers

Order results

Result details

Show export options Show export options

Select all

Export citation of selected articles as:

Research

Jump to: Review

13858 KiB

Open AccessArticle

TiO₂ Nanotubes Supported Cu Nanoparticles for Improving Photocatalytic Degradation of Simazine under UV Illumination

by Syazwan Hanani Meriam Suhaimy, Sharifah Bee Abd Hamid, Chin Wei Lai, Md. Rakibul Hasan and Mohd Rafie Johan

Catalysts 2016, 6(11), 167; https://doi.org/10.3390/catal6110167 - 29 Oct 2016

Cited by 19 | Viewed by 6144

Abstract

Nano size Copper (Cu) incorporated TiO₂ nanotubes was successfully synthesized via the anodic oxidation technique in ethylene glycol (EG) containing 0.5 wt % NH₄F and 1.6 wt % KOH for the photocatalytic degradation of Simazine (2-chloro-4, 6-diethylamino-1,3,5-triazine) under Ultraviolet (UV) illumination. In the present study, the influence of different loading Cu concentrations on the formation of Cu-TiO₂ nanotubes film towards the photocatalytic degradation of Simazine is reported. Based on our study, it was found that the optimum Cu loading concentration was about 0.45 wt % on TiO₂ nanotubes film for approximately 64% photocatalytic degradation of Simazine after 4 h under UV illumination. This finding was mainly attributed to the uniform surface covering of the Cu loaded TiO₂NTs which acted as electron traps, preventing the recombination of electron hole pairs, eventually leading to higher photocatalytic activity of our photocatalyst in degrading the targeted organic pollutant, Simazine. Moreover, an increased kinetic rate of the degradation to 0.0135 h⁻¹ was observed in the presence of Cu in TiO₂NTs. Full article

(This article belongs to the Special Issue Photocatalytic Wastewater Treatment)

► Show Figures

Graphical abstract

6402 KiB

Open AccessArticle

A Highly Efficient Dual Rotating Disks Photocatalytic Fuel Cell with Wedged Surface TiO₂ Nanopore Anode and Hemoglobin Film Cathode

by Chen Yang, Yi He, Kan Li, Diwen Ying, Ye Yao, Tiantian Tang, Yalin Wang and Jinping Jia

Catalysts 2016, 6(8), 114; https://doi.org/10.3390/catal6080114 - 4 Aug 2016

Cited by 20 | Viewed by 4886

Abstract

In this study, a dual rotating-disk photocatalytic fuel cell using TiO₂ on Ti plate with a wedged surface as the anode and hemoglobin (Hb) on graphite as the cathode was investigated and found to show excellent performance of simultaneous organic pollutant degradation and electricity generation. This study is based on a well-developed photocatalytic fuel cell equipped with dual rotating disks for wastewater treatment that we developed previously, and the innovation of this new device is using a hemoglobin on graphite cathode for in situ hydrogen peroxide (H₂O₂) generation. The result proved with confidence that H₂O₂ was generated in situ on a cathode surface with the exited electron transferred from organic oxidation in a photoanodic half cell, and the organic pollutants were removed by the reaction with H₂O₂ and ·OH in a cathodic half cell. This design uses the invalid excited electron from the photoanode and enhances the overall performance of Rhodamine B degradation compared with the cells using the cathode without Hb. Compared with traditional photocatalytic reactors, the photocatalytic fuel cell developed above shows much better utilization efficiency of incident light and a higher degradation performance of organic pollutants and a larger photocurrent. Full article

(This article belongs to the Special Issue Photocatalytic Wastewater Treatment)

► Show Figures

Graphical abstract

5100 KiB

Open AccessArticle

Highly Crystallized C-Doped Mesoporous Anatase TiO₂ with Visible Light Photocatalytic Activity

by Chong Xie, Shenghui Yang, Jianwen Shi and Chunming Niu

Catalysts 2016, 6(8), 117; https://doi.org/10.3390/catal6080117 - 1 Aug 2016

Cited by 41 | Viewed by 7428

Abstract

Highly crystallized C-doped mesoporous anatase TiO₂ is prepared using a multi-walled carbon nanotube (MWCNT) mat as both a “rigid” pore template and a carbon doping source. SEM and TEM characterization shows that the MWCNT template imposed a pore structure in reverse of that of the MWCNT mat. The pore walls are formed by chain-like interconnected TiO₂ nanocrystals with an average diameter about 10 nm, and pores are derived from spaces occupied by MWCNTs before removal. XRD characterization shows that TiO₂ is crystallized with a pure anatase phase. XPS characterization reveals that the relative carbon content in the TiO₂ is related to the duration of TiO₂/MWCNT composite annealing before removal of MWCNT template. Three samples prepared contain 2.3%, 2.8% and 3.9% carbon; show a ~30 nm red shift and a plateau of adsorption from 450–800 nm in UV–Vis spectra in comparison to that of P25; and display visible light photocatalytic activity for decomposition of methyl orange (MO) in relationship with the carbon content and crystallinity of the anatase TiO₂. Full article

(This article belongs to the Special Issue Photocatalytic Wastewater Treatment)

► Show Figures

Graphical abstract

14251 KiB

Open AccessArticle

Fabrication of Hierarchically Porous Reduced Graphene Oxide/SnIn₄S₈ Composites by a Low-Temperature Co-Precipitation Strategy and Their Excellent Visible-Light Photocatalytic Mineralization Performance

by Fang Deng, Xule Pei, Yiting Luo, Xubiao Luo, Dionysios D. Dionysiou, Shaolin Wu and Shenglian Luo

Catalysts 2016, 6(8), 113; https://doi.org/10.3390/catal6080113 - 29 Jul 2016

Cited by 45 | Viewed by 9826

Abstract

Hierarchically porous reduced graphene oxide/SnIn₄S₈ (RGO/SnIn₄S₈) composites with visible-light response and strong mineralization ability were first successfully prepared by a facile low-temperature co-precipitation method, and were characterized by X ray diffraction (XRD), scanning electron microscope (SEM), Brunauer-Emmet-Teller (BET), UV-Visible spectrophotometer (UV-Vis), Raman spectra and Photoluminescence (PL) techniques. RGO/SnIn₄S₈ composite exhibits strong absorption in UV and visible-light range. The optimized 5% RGO/SnIn₄S₈ possesses the optimal photocatalytic degradation efficiency and the best mineralization performance with complete degradation of Rhodamine B (RhB) within 70 min and 73.17% mineralization yield within 160 min under visible-light irradiation, which is much higher than that of pure SnIn₄S₈. The main reactive species, which play crucial roles in the degradation and mineralization of RhB, follow the order of h⁺ > ·O₂⁻ > ·OH. The intermediate products of RhB degradation were analyzed by using high performance liquid chromatography-tandem mass spectrometry (HPLC-MS), and the possible degradation pathways and mechanism were proposed. Moreover, 5% RGO/SnIn₄S₈ exhibits excellent reusability and stability without an obvious decrease in photocatalytic activity after four consecutive photocatalytic degradation-regeneration experiments. Full article

(This article belongs to the Special Issue Photocatalytic Wastewater Treatment)

► Show Figures

Graphical abstract

1780 KiB

Open AccessArticle

Photocatalytic Removal of Microbiological Consortium and Organic Matter in Greywater

by Nazmiye Cemre Birben, Ceyda Senem Uyguner-Demirel and Miray Bekbolet

Catalysts 2016, 6(6), 91; https://doi.org/10.3390/catal6060091 - 22 Jun 2016

Cited by 12 | Viewed by 4978

Abstract

This study aimed to investigate TiO₂ photocatalytic degradation of synthetically-prepared greywater samples with differing compositional contents of organic matter (OM), anion concentration, and microbiological consortium. Treatment efficiency was followed through removal of organic matter content in terms of dissolved organic carbon (DOC), specific spectroscopic parameters, and bacterial inactivation. Photocatalytic degradation kinetics were expressed by pseudo first-order kinetic modeling. The best DOC removal rates were attained for greywater samples containing OM with lower molecular size fractions. In addition, either enhancing or reducing the effect of common anions as radical scavengers were observed depending on the composition and concentration of variables in the greywater matrix. Moreover, possibility of a photocatalytic disinfection process was found to be of a bacteria type specific in OM-loaded synthetic greywater samples. Photocatalytic destruction of fecal streptococci required longer irradiation periods under all conditions. Bacterial removal rates were found to be in the order of total coliform > fecal coliform > fecal streptococci, for low organic load greywater, and fecal coliform > total coliform > fecal streptococci, for high organic load greywater. Full article

(This article belongs to the Special Issue Photocatalytic Wastewater Treatment)

► Show Figures

Figure 1

4616 KiB

Open AccessArticle

Kinetic Model for Simultaneous Adsorption/Photodegradation Process of Alizarin Red S in Water Solution by Nano-TiO₂ under Visible Light

by Rita Giovannetti, Elena Rommozzi, Chiara Anna D’Amato and Marco Zannotti

Catalysts 2016, 6(6), 84; https://doi.org/10.3390/catal6060084 - 8 Jun 2016

Cited by 18 | Viewed by 6699

Abstract

The simultaneous adsorption and visible light photodegradation of Alizarin Red S in water solutions were studied in real time mode by using nano-TiO₂, such as Anatase and Aeroxide P-25, supported on polypropylene strips. Kinetic results of the overall process were compared with those obtained from separated steps of adsorption and photodegradation previously studied; kinetic advantages were evidenced with the simultaneous approach. From the study of different dye concentrations, a kinetic model has been proposed which describes the overall process. This model considered two consecutive processes: The adsorption of dye on TiO₂ surface and its photodegradation. The obtained results were in good agreement with experimental data and can predict the profiles of free dye, dye adsorbed on TiO₂ and photoproduct concentrations during the total process. Full article

(This article belongs to the Special Issue Photocatalytic Wastewater Treatment)

► Show Figures

Graphical abstract

3081 KiB

Open AccessArticle

Synthesis and Characterization of Ag-Ag₂O/TiO₂@polypyrrole Heterojunction for Enhanced Photocatalytic Degradation of Methylene Blue

by Rajeev Kumar, Reda M. El-Shishtawy and Mohamed A. Barakat

Catalysts 2016, 6(6), 76; https://doi.org/10.3390/catal6060076 - 25 May 2016

Cited by 70 | Viewed by 10321

Abstract

Hybrid multi-functional nanomaterials comprising two or more disparate materials have become a powerful approach to obtain advanced materials for environmental remediation applications. In this work, an Ag-Ag₂O/TiO₂@polypyrrole (Ag/TiO₂@PPy) heterojunction has been synthesized by assembling a self-stabilized Ag-Ag₂O (p type) semiconductor (denoted as Ag) and polypyrrole (π-conjugated polymer) on the surface of rutile TiO₂ (n type). Ag/TiO₂@PPy was synthesized through simultaneous oxidation of pyrrole monomers and reduction of AgNO₃ in an aqueous solution containing well-dispersed TiO₂ particles. Thus synthesized Ag/TiO₂@PPy was characterized using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), and UV-Vis diffuse reflectance spectroscopy (UV-vis DSR). The photocatalytic activity of synthesized heterojunction was investigated for the decomposition of methylene blue (MB) dye under UV and visible light irradiation. The results revealed that π-conjugated p-n heterojunction formed in the case of Ag/TiO₂@PPy significantly enhanced the photodecomposition of MB compared to the p-n type Ag/TiO₂ and TiO₂@PPy (n-π) heterojunctions. A synergistic effect between Ag-Ag₂O and PPy leads to higher photostability and a better electron/hole separation leads to an enhanced photocatalytic activity of Ag/TiO₂@PPy under both UV and visible light irradiations. Full article

(This article belongs to the Special Issue Photocatalytic Wastewater Treatment)

► Show Figures

Figure 1

3252 KiB

Open AccessArticle

A Novel Delafossite Structured Visible-Light Sensitive AgFeO₂ Photocatalyst: Preparation, Photocatalytic Properties, and Reaction Mechanism

by Lu Yin, Yubin Shi, Lian Lu, Rongye Fang, Xiankai Wan and Huixiang Shi

Catalysts 2016, 6(5), 69; https://doi.org/10.3390/catal6050069 - 10 May 2016

Cited by 53 | Viewed by 8671

Abstract

This work presents a systematic study of a novel efficient visible-light sensitive AgFeO₂ photocatalyst. The photocatalysts were prepared via simple hydrothermal procedure at 160 °C with different reaction time. The structures, morphologies, specific surface areas, and optical properties of the photocatalysts were explored by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), Brunauer-Emmett-Teller (BET) model, and UV-vis diffuse reflectance spectra (DRS). Photoluminescence and photocurrent analysis were conducted for the understanding of photogenerated electron-hole pair separation. AgFeO₂ with a six-hour hydrothermal procedure demonstrated the most efficient photocatalytic performance which resulted in 97% degradation of methyl orange (MO) within 180 min. The enhanced photocatalytic activity was attributed to the combined effect of its relatively large surface area and high separation electron-hole pair efficiency. Holes and ·O₂⁻ were the dominant reactive species responsible for MO degradation and holes played the leading role according to the quenching effects analysis and detection of active species. The conduction and valence band position of AgFeO₂ were calculated to be −0.5 V and 1.32 V, respectively. Based on active species detection, along with the band structure, the photocatalytic mechanism was proposed. Full article

(This article belongs to the Special Issue Photocatalytic Wastewater Treatment)

► Show Figures

Graphical abstract

Review

Jump to: Research

4718 KiB

Open AccessReview

Advances in Magnetically Separable Photocatalysts: Smart, Recyclable Materials for Water Pollution Mitigation

by Gcina Mamba and Ajay Mishra

Catalysts 2016, 6(6), 79; https://doi.org/10.3390/catal6060079 - 20 Jun 2016

Cited by 105 | Viewed by 10413

Abstract

Organic and inorganic compounds utilised at different stages of various industrial processes are lost into effluent water and eventually find their way into fresh water sources where they cause devastating effects on the ecosystem due to their stability, toxicity, and non-biodegradable nature. Semiconductor photocatalysis has been highlighted as a promising technology for the treatment of water laden with organic, inorganic, and microbial pollutants. However, these semiconductor photocatalysts are applied in powdered form, which makes separation and recycling after treatment extremely difficult. This not only leads to loss of the photocatalyst but also to secondary pollution by the photocatalyst particles. The introduction of various magnetic nanoparticles such as magnetite, maghemite, ferrites, etc. into the photocatalyst matrix has recently become an area of intense research because it allows for the easy separation of the photocatalyst from the treated water using an external magnetic field. Herein, we discuss the recent developments in terms of synthesis and photocatalytic properties of magnetically separable nanocomposites towards water treatment. The influence of the magnetic nanoparticles in the optical properties, charge transfer mechanism, and overall photocatalytic activity is deliberated based on selected results. We conclude the review by providing summary remarks on the successes of magnetic photocatalysts and present some of the future challenges regarding the exploitation of these materials in water treatment. Full article

(This article belongs to the Special Issue Photocatalytic Wastewater Treatment)

► Show Figures

Journal Menu

Journal Browser

Photocatalytic Wastewater Treatment

Share This Special Issue

Special Issue Editors

Special Issue Information

Keywords

Benefits of Publishing in a Special Issue

Published Papers (9 papers)

Research

Review

Further Information

Guidelines

MDPI Initiatives

Follow MDPI