Submit to Special Issue Submit Abstract to Special Issue Review for Catalysts Propose a Special Issue

Journal Menu

Journal Browser

► Journal Browser

Photocatalyzed and Electrochemical Processes for a Cleaner Environment

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: 30 April 2025 | Viewed by 10793

Share This Special Issue

Special Issue Editor

Dr. Reyna Natividad

E-Mail Website
Guest Editor

Joint Center for Research on Sustainable Chemistry UAEM-UNAM, Autonomous University of the State of Mexico, Toluca 50200, Mexico
Interests: physical and chemical removal of persistent contaminants using new and innovative biomaterials, biochar, and nanomaterials; lifecycle analysis of the chemical removal of persistent contaminants
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

Around the globe, the natural environment has been deteriorating due to, among other factors, human activities (food, pharmaceutical and fuel production, waste management, travel, communications, etc.). The actions required to remediate such a phenomenon can be classified into two large groups: preventive and corrective. For both of them, photocatalyzed and electrochemical processes emerge as promising alternatives and, therefore, are worthy of being assessed to increase their number of applications. In the context of prevention, these processes allow us, for instance, to conduct selective partial oxidations or reductions under mild temperature and pressure conditions. Such processes can also be applied to correct an environmental problem in air, water and soil. Therefore, this Special Issue, “Photocatalyzed and electrochemical Processes for a Cleaner Environment”, is dedicated to addressing topics related with to the following:

Development of novel photocatalysts and electrodes;
Photocatalyzed and electrochemical advanced oxidation processes, i.e., photocatalysis, elctrocatalysis, electro-oxidation, electroperoxonation, electrocoagulation, photo-Fenton, electro-Fenton, and photo-electrocatalysis;
Reduction processes, i.e., CO₂ conversion through photocatalyzed and/or electrochemical processes;
Selective photocatalyzed or photo-electrocatalyzed oxidations;
Fuels production through photocatalyzed and/or electrochemical processes;
Integration of photocatalyzed processes with others (adsorption, biological, ozone, electrochemical, and persulfate) for pollutant removal;
Plasmonic photocatalysis;
Water splitting;
Photoelectrochemical cells;
Photocatalysis–biocatalysis hybrid systems;
Electrochemical–biological cells;
Valorization of residues through photocatalyzed and/or electrochemical processes;
Life cycle assessment of photocatalyzed and/or electrochemical processes;
Scaling-up and optimization of photocatalyzed and/or electrochemical processes;
Mechanistic insights and computational studies on photocatalyzed and/or electrochemical processes.

Dr. Reyna Natividad
Guest Editor

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

photocatalysis
electrocatalysis
advanced oxidation processes
photo-fenton
electro-fenton
water splitting
CO₂ reduction
electrochemical cells
photoelectrochemical cells (PECs)
photocatalysts development
plasmonic photocatalysis
life cycle assessment (LCA)
electrorefinery
electrocoagulation
hydrogen production

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

19 pages, 4003 KiB

Open AccessArticle

Plasmon-Enhanced CO₂ Reduction to Liquid Fuel via Modified UiO-66 Photocatalysts

by Alaa Elsafi, Zeineb Theihmed, Amna Al-Yafei, Alaa Alkhateeb, Ahmed Abotaleb, Muhammad Anwar, Kamal Mroue, Brahim Aissa and Alessandro Sinopoli

Catalysts 2025, 15(1), 70; https://doi.org/10.3390/catal15010070 - 14 Jan 2025

Viewed by 614

Abstract

Metal–organic frameworks (MOFs) have emerged as versatile materials with remarkably high surface areas and tunable properties, attracting significant attention for various applications. In this work, the modification of a UiO-66 MOF with metal nanoparticles (NPs) is investigated for the purpose of enhancing its photocatalytic activity for CO₂ reduction to liquid fuels. Several NPs (Au, Cu, Ag, Pd, Pt, and Ni) were loaded into the UiO-66 framework and employed as photocatalysts. The synergistic effects of plasmonic resonance and MOF characteristics were investigated to improve photocatalytic performance. The synthesized materials were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS), confirming the successful integration of metal NPs onto the UiO-66 framework. Morphological analysis revealed distinct distributions and sizes of NPs on the UiO-66 surface for different metals. Photocatalytic CO₂ reduction experiments demonstrated enhanced activity of plasmonic MOFs, yielding methanol and ethanol. The findings revealed by this study provide valuable insights into tailoring MOFs for improved photocatalytic applications through the incorporation of plasmonic metal nanoparticles. Full article

(This article belongs to the Special Issue Photocatalyzed and Electrochemical Processes for a Cleaner Environment)

► Show Figures

Figure 1

26 pages, 6617 KiB

Open AccessArticle

Optimization of Solar Corrosion Fenton Reactor for the Recovery of Textile Wastewater: In Situ Release of Fe²⁺

by Ana Fernanda Tenorio-Hernández, Ivonne Linares-Hernández, Luis Antonio Castillo-Suárez, Verónica Martínez-Miranda and Carolina Álvarez-Bastida

Catalysts 2025, 15(1), 63; https://doi.org/10.3390/catal15010063 - 12 Jan 2025

Viewed by 605

Abstract

A Solar Corrosion Fenton reactor (SCFr) was developed by packing an iron-carbon steel filament inside the reactor to enable the in situ release of Fe²⁺. A Box–Behnken experimental design was used to optimize the effect of HRT (20, 30, and 40 min), the mass ratios of the packed filament inside the reactor with respect to volume (0.1, 0.2, 0.3 w/v), and the peroxide dosage added (500, 1000, and 1500 mg/L), the response variables were the percentage removal of COD, color, and turbidity. The optimum conditions for SCFr were an HRT of 24.5 min, a ratio of 0.16 (0.0032 m²/L), and a peroxide dose of 1006.9 mg/L. The removal was 91.8%, 98.4%, and 87.3% COD, color, and turbidity, respectively. Without solar radiation, the percentage removal was reduced by 16.3%, 47.9%, and 34.0% in terms of COD, color, and turbidity, respectively. The concentration of Fe²⁺ released was 25.4 mg/L of Fe²⁺. Prolonged HRT increases Fe²⁺ concentration and turbidity, which increase COD. The oxidation kinetics were fitted to a Behnajady–Modirshahla–Ghanbery (BMG) model, which indicated a high oxidation rate that is reflective of low treatment times. The w/v ratio was the most significant factor; the release of Fe²⁺ was stimulated by UV radiation and the chloride concentration of wastewater, which prevents the formation of an oxide layer, thus allowing its continuous release, taking advantage of solar radiation and the pH and chloride concentration of the raw sample. Full article

(This article belongs to the Special Issue Photocatalyzed and Electrochemical Processes for a Cleaner Environment)

► Show Figures

Figure 1

25 pages, 4157 KiB

Open AccessArticle

Textile Wastewater Coupled Treatment Implementing Enhanced Ozonation with Fenton-like Processes and Phytoremediation

by Jazmin A. Reyes-Pérez, Araceli Amaya-Chávez, Gabriela Roa-Morales, Patricia Balderas-Hernández, Thelma B. Pavón Silva, Teresa Torres-Blancas and Carlos E. Barrera-Díaz

Catalysts 2025, 15(1), 43; https://doi.org/10.3390/catal15010043 - 6 Jan 2025

Viewed by 512

Abstract

In this contribution, we described how phytoremediation using M. aquaticum is feasible with coupled ozonation/Fenton-like processes in real wastewater from the denim textile industry, with the purpose of removing color and, therefore, highly polluting particles. For the ozonation/Fenton-like process, pHs of 3 and 9 were evaluated using a copper-enriched pumice to activate the catalytic processes carried out in the Fenton-like reactions. Subsequently, phytoremediation was carried out using M. aquaticum to completely degrade the by-products generated from the ozone/Fenton-like process. Plant health was controlled through the determination of chlorophylls and carotenes. All the analyses were monitored by COD, UV–Vis spectrophotometry for the determinations of color quantification in the wastewater and oxidizable organic matter, and SEM/EDS for the characterization of the material and XPS to corroborate the oxidation state of the copper that gives rise to radical species. The results indicate that, at pH 3.0, the ozonation process with the PMPCu catalyst at 1 g/L is the most efficient, achieving a percentage of color removal of 86.79 ± 1.3% and COD of 76.19%, which is consistent with the optimization analysis of the experimental design. The residual color and its degradation by-products were eliminated by phytoremediation. Full article

(This article belongs to the Special Issue Photocatalyzed and Electrochemical Processes for a Cleaner Environment)

► Show Figures

Figure 1

16 pages, 3337 KiB

Open AccessArticle

Metronidazole Electro-Oxidation Degradation on a Pilot Scale

by Sandra María Maldonado Domínguez, Carlos Eduardo Barrera-Díaz, Patricia Balderas Hernández, Deysi Amado-Piña, Teresa Torres-Blancas and Gabriela Roa-Morales

Catalysts 2025, 15(1), 29; https://doi.org/10.3390/catal15010029 - 31 Dec 2024

Viewed by 430

Abstract

In this investigation, metronidazole was degraded in an aqueous solution through electro-oxidation. A DiaClean^® cell was used to accommodate a stainless-steel electrode as a cathode and a boron-doped diamond (BDD) electrode as anode. This setup provides several electrochemical advantages, including low currents, a high operational potential, and, frequently, low adsorption compared to conventional carbon materials. The physicochemical parameters were estimated after 180 min of treatment, applying different current densities. The concentration of metronidazole was monitored by HPLC to assess degradation, resulting in 30.67% for 30 mA cm⁻², 79.4% for 50 mA cm⁻², and 100% for 100 mA cm⁻². The TOC mineralization percentages were 12.71% for 30 mA cm⁻², 14.8% for 50 mA cm⁻², and 29.9% for 100 mA cm⁻². Also, biodegradability indices of 0.70 for 30 mA cm⁻², 0.81 for 50 mA cm⁻², and 0.93 for 100 mA cm⁻² were obtained. The byproducts found were formic acid and acetic acid. A pseudo-first order kinetic model was thus obtained due to the quasi-stable concentration achieved through hydroxyl radicals, given that they do not accumulate in the medium, due to their high rate of destruction and short lifespan. Full article

(This article belongs to the Special Issue Photocatalyzed and Electrochemical Processes for a Cleaner Environment)

► Show Figures

Graphical abstract

28 pages, 12281 KiB

Open AccessArticle

Electrochemical Mineralization of Chloroquine in a Filter-Press-Type Flow Reactor in Batch Recirculation Mode Equipped with Two Boron-Doped Diamond Electrodes: Parametric Optimization, Total Operating Cost, Phytotoxicity Test, and Life Cycle Assessment

by Alejandro Regalado-Méndez, Juliana Zavaleta-Avendaño, Claudia Alanis-Ramírez, Deysi Amado-Piña, Armado Ramírez Serrano and Ever Peralta-Reyes

Catalysts 2024, 14(12), 918; https://doi.org/10.3390/catal14120918 - 12 Dec 2024

Viewed by 1206

Abstract

This study investigated the electro-mineralization of chloroquine (CQ) in a filter-press-type flow reactor using two BDD electrodes operating in batch recirculation mode. The optimal operating parameters were established using response surface methodology (RSM) and central composite rotatable design (CCRD) with three parameters: current density (j), initial pH (pH₀), and volumetric flow rate (Q), with the mineralization efficiency of (CQ) and specific energy consumption (SEC) as responses. Optimal operating parameters were j = 155.0 mA/cm², pH₀ = 9.75, and Q = 0.84 L/min within a reaction time of 9 h, leading to a maximum mineralization efficiency of CQ of 52.59% and a specific energy consumption of 15.73 kW/mg TOC, with a total operating cost of USD 0.18 per liter. Additionally, an ultra-high-performance chromatography study identified three by-products (4-amino-7-choloroquinoline, formic acid, and acid acetic) of CQ degradation. Furthermore, the phytotoxicity test indicates that the electrochemical wastewater proposed decreased the effluent’s phytotoxicity, and an increase in the percentage of Vigna radiata germination was observed. The carbon footprint of optimized electrochemical mineralization of chloroquine is 2.48 kg CO₂ eq., representing a 48% reduction in cumulative energy demand (CED) when the source of energy is a mixture of fossil fuels (50%), wind (25%), and photovoltaic (25%) energy. Full article

(This article belongs to the Special Issue Photocatalyzed and Electrochemical Processes for a Cleaner Environment)

► Show Figures

Graphical abstract

8 pages, 1257 KiB

Open AccessCommunication

Quinoline Hydroxyalkylations from Iron-Catalyzed, Visible-Light-Driven Decarboxylations

by Zita G. Ríos-Malváez, Nelly González-Rivas and Erick Cuevas-Yañez

Catalysts 2024, 14(12), 916; https://doi.org/10.3390/catal14120916 - 12 Dec 2024

Viewed by 732

Abstract

One of the current challenges in organic synthesis is the direct alkylation of heterocyclic systems with a minimal impact on the environment. In this report, 4-substituted hydroxyalkyl quinolines were obtained by treating quinoline with different alkyl carboxylic acids in the presence of catalytic amounts of an iron (III) chloride–phenanthroline complex. The reaction was mediated by blue LED light under acidic conditions as a cleaner alternative to conventional heating, reducing the use of harmful substances. Full article

(This article belongs to the Special Issue Photocatalyzed and Electrochemical Processes for a Cleaner Environment)

► Show Figures

Figure 1

14 pages, 2226 KiB

Open AccessArticle

Unraveling the Environmental Applications of Nanoporous Ultrananocrystalline Diamond Films

by Laís G. Vernasqui, Inalmar D. Barbosa Segundo, Carlos A. Martínez-Huitle, Neidenêi G. Ferreira and Manuel A. Rodrigo

Catalysts 2024, 14(12), 872; https://doi.org/10.3390/catal14120872 - 29 Nov 2024

Viewed by 602

Abstract

In this work, a nanoporous ultrananocrystalline diamond film (B-UNCDWS/TDNT/Ti) was obtained and compared with a commercial electrode in the degradation of methomyl, a recalcitrant pesticide. The morphological and structural differences between the materials were highlighted by SEM and XRD analysis: while the commercial electrode presented a regular and planar surface with microcrystalline grains, supported by XRD features, the B-UNCDWS/TDNT/Ti electrode presented a porous morphology with DRX features indicating a high film renucleation rate. Those differences affected the electrooxidation of methomyl; B-UNCDWS/TDNT/Ti was responsible for faster and more economic degradation of the pollutant, achieving a methomyl degradation of 78% (against 35% by the commercial electrode). The highly porous surface of UNCDWS/TDNT/Ti provides an electrochemical area threefold greater than the one found in the commercial electrode, justifying the better efficiency in the formation of persulfate, which can be singled out as the main mechanism in methomyl degradation. Full article

(This article belongs to the Special Issue Photocatalyzed and Electrochemical Processes for a Cleaner Environment)

► Show Figures

Figure 1

19 pages, 4137 KiB

Open AccessFeature PaperArticle

Au Supported on Bovine-Bone-Derived Hydroxyapatite Catalyzes CO₂ Photochemical Reduction toward Methanol

by Sergio Arturo Gama-Lara, Alfredo Rafael Vilchis-Néstor, Deysi Amado-Piña and Reyna Natividad

Catalysts 2024, 14(7), 417; https://doi.org/10.3390/catal14070417 - 29 Jun 2024

Cited by 2 | Viewed by 1210

Abstract

In this work, gold-photo-catalyzed CO₂ transformation was conducted and the effect of three variables with two levels was investigated: support (TiO₂ and hydroxyapatite from bovine bone (BB)), Au content (5 and 10%) and activation wavelength (254 and 380–700 nm). Reactions were conducted in a stirred tank reactor by bubbling CO₂ (9 × 10⁻³ dm³/min) in 0.1 dm³ of 0.5 M NaOH solution. The catalysts were synthesized using AuCl₃, TiO₂ and BB. Au nanoparticles were obtained by reduction with Hetheroteca inuloides, thus eliminating calcination and hydrogenation to reduce the gold species. By TEM, the particle size distribution was determined, and the synthesized nanoparticle sizes varied in the range of 9 to 19 nm, depending on the support and Au content. By UV–Vis spectroscopy, the energy band gaps of the prepared materials were 2.18 eV (10% Au/BB), 2.38 eV (5% Au/BB), 2.42 eV (BB), 3.39 eV (5% Au/TiO₂), 3.41 eV (10% Au/TiO₂) and 3.43 eV for pure TiO₂. Methanol and formic and acetic acids were identified during the process. Selectivity toward methanol was found to be improved with the 10% Au/BB catalytic system. Full article

(This article belongs to the Special Issue Photocatalyzed and Electrochemical Processes for a Cleaner Environment)

► Show Figures

Figure 1

12 pages, 6479 KiB

Open AccessArticle

Simultaneous Oxidation of Emerging Pollutants in Real Wastewater by the Advanced Fenton Oxidation Process

by Alexis Rubén Bracamontes-Ruelas, Yolanda Reyes-Vidal, José Rafael Irigoyen-Campuzano and Liliana Reynoso-Cuevas

Catalysts 2023, 13(4), 748; https://doi.org/10.3390/catal13040748 - 14 Apr 2023

Cited by 6 | Viewed by 3649

Abstract

Since the conventional processes employed in most wastewater treatment plants (WWTPs) worldwide are not designed to entirely remove or oxidize emerging pollutants, which, due to their incidence and persistence, can cause damage to both the environment and human health, several options for their degradation and removal have emerged. Coupling the advanced Fenton oxidation process as a polishing or tertiary wastewater treatment alternative within conventional WWTP processes stands out among the treatment options. Therefore, the main objective of this research was to evaluate, at the laboratory level, the ability of the advanced Fenton oxidation process to oxidize triclosan, ibuprofen, DEET (N, N-diethyl-meta-toluamide), carbamazepine, caffeine, and acesulfame-K, which represent several groups of emerging pollutants in real wastewater from the second settling tank of a municipal WWTP. The compound used as a catalyst (Fe²⁺) supplier in the advanced Fenton oxidation process was ferrous sulfate heptahydrate (FeSO₄•7H₂O). The results obtained upon application showed that the advanced Fenton oxidation process could simultaneously oxidize and remove practically the total concentration of the above-mentioned emerging pollutants, except for DEET (85.21%), in conjunction with the chemical oxygen demand (COD), total suspended solids (TSS), and fecal coliforms (FC, pathogen group) in the effluent generated by the advanced Fenton oxidation process. Full article

(This article belongs to the Special Issue Photocatalyzed and Electrochemical Processes for a Cleaner Environment)

► Show Figures

Journal Menu

Journal Browser

Photocatalyzed and Electrochemical Processes for a Cleaner Environment

Share This Special Issue

Special Issue Editor

Special Issue Information

Keywords

Benefits of Publishing in a Special Issue

Published Papers (9 papers)

Research

Further Information

Guidelines

MDPI Initiatives

Follow MDPI