Photodegradation Of Ciprofloxacin Research Articles

The construction of novel CuO/SnO2@g-C3N4 photocatalyst for efficient degradation of ciprofloxacin, methylene blue and photoinhibition of bacteria through efficient production of reactive oxygen species

Water pollution due to organic waste and various microorganisms cause severe health problems. Numbers of techniques are used to eliminate organic waste and microorganisms from water because water pollution is a substantial issue in the current era. In the present study, sustainable and effective CuO/SnO2@g-C3N4 nanocomposites were prepared via green and chemical approach. The photo degradation of ciprofloxacin (CIP) and methylene blue (MB) by the green synthesized nanocomposite were tested. Visible and dark conditions both were used to conduct this test. The results showed that the nanocomposite is much more effective in light than in dark conditions. The synthesized nanocomposite was also tested both in light and dark against highly drug resistant microorganisms’ Bacillus subtilis (B.subtilis) and Escherichia coli (E.coli). As a result, the antibacterial evaluation revealed substantial antibacterial activity in the presence of light, with a zone of inhibition covering an area of 19 (±0.5) mm and 20 (±0.1) mm, respectively, against gram negative and gram positive bacteria such as E. coli and B. subtilis. The results showed that the CuO/SnO2@g-C3N4 nanocomposite is a stable, eco-friendly photocatalyst with significant resistance to CIP and MB degradation and a substantial inhibitory effect towards microorganisms in visible light.

Synthesis of cake-like Ti-Bi bimetallic MOFs-derived OV-rich A-TiO2/β-Bi2O3 heterojunctions for photodegradation of ciprofloxacin

The cake-like Ti-Bi bimetallic MOFs and MOFs-derived oxygen vacancy-rich (OV-rich) A-TiO2/β-Bi2O3 heterojunctions were synthesized by solvothermal and high-temperature calcination techniques and applied to the degradation of ciprofloxacin (CIP). The cake-like morphology of the inherited parent MOFs allowed the A-TiO2/β-Bi2O3 heterojunctions to expose more active sites, which facilitated the enrichment of CIP. Under visible light, the synergistic effect of abundant oxygen vacancies (OV) and heterojunction results in stronger photo-responsiveness, higher photogenerated carrier separation efficiency and low recombination rate of A-TiO2/β-Bi2O3. The results of EPR as well as photodegradation CIP experiments show that heterojunction A-TiO2/β-Bi2O3 has more abundant OV and superior photocatalytic activity compared with monometallic MOFs derivatives (A/R-TiO2 and α-Bi2O3). Theoretical calculations reveal that OV can modulate the electronic and energy band structure of the material surface. In this study, new bimetallic MOFs were prepared, and OV-rich heterojunctions derived from MOFs were developed for the efficient degradation of pollutants under visible light.

Construction of 2D/2D Bi4O5Br2/Bi2WO6 Z-scheme heterojunction for highly efficient photodegradation of ciprofloxacin under visible light

Enhancing the heterointerface contact determined by the dimensionality of each component is essential for the rapid migration of photogenerated charge carriers. Herein, the 2D/2D Bi4O5Br2/Bi2WO6 Z-scheme heterojunction was successfully synthesized through a simple chemical co-precipitation followed by a hydrothermal process. Remarkably, the optimized Bi4O5Br2/Bi2WO6 heterojunction achieved superior photocatalytic efficiency of 91.0% and ascendant stability for the degradation of ciprofloxacin (CIP) under visible light illumination. More importantly, degradation pathway and photocatalytic mechanism analysis revealed that the reinforced photodegradation efficiency can be ascribed to the intimate heterointerface between 2D Bi4O5Br2 and 2D Bi2WO6, which facilitated the fast migration and separation of photoinduced carriers, thus enhancing the photocatalytic activity. Furthermore, the effect of pH, CIP concentration, inorganic cations and anions, and different contaminants were systematically investigated to explore the potential of practical applications. This work gives rational insight into the developing 2D/2D Z-scheme heterojunction for environmental remediation.

Efficient degradation of ciprofloxacin by Cu2O/g-C3N4 heterostructures with different morphologies driven under the visible light

In this study, Cu2O/g-C3N4 composite with photocatalytic activity was successfully prepared by chemical precipitation method. The catalytic degradation of ciprofloxacin (CIP) by Cu2O and Cu2O/g-C3N4 composites with different morphologies was investigated. The effective structure and properties of Cu2O/g-C3N4 composites were tested by a series of characterization methods. The photocatalytic test results show that the Cu2O/g-C3N4 composite photocatalyst has good stability and good photocatalytic performance, which is attributed to the effective hetero-junction structure formed by the combination of Cu2O and g-C3N4, which promotes the interfacial charge separation. The addition of g-C3N4 can reduce the crystal size of Cu2O, improve the crystal morphology, and increase its light utilization. Among the synthesized catalysts, the Cu2O-3(20%)/g-C3N4 composite has the highest catalytic activity, and the photocatalytic oxidation efficiency of CIP is 96%. By free radical capture and ESR analysis, it was verified that OH, h+ and O2− radicals may be the main active substances involved in CIP photodegradation. Finally, various degradation products and intermediates of CIP were identified by LC-MS, and the possible conversion pathways were proposed.

Insights into adsorption and high photocatalytic oxidation of ciprofloxacin under visible light by intra-molecular Donor-Acceptor like p-n isotype heterojunction: Performance and mechanism

Antibiotics, e.g. ciprofloxacin (CIP) are frequently detected in natural waters and sewage, however, the conventional sewage treatment techniques presents a great challenge for efficient removal them due to the inhibition of bacterial proliferation. Herein, the intra-molecular Donor-Acceptor like p-n isotype heterojunction of phosphorus and boron co-doped hollow tubular g-C3N4 (xB-PCN) was synthesized for high-efficiency visible light photocatalytic degradation of CIP. The Mott-Schottky curves showed that the xB-PCN exhibited both p and n-type conductivities, which probably because the doped boron has electron acceptor effect and the NH/NH2 groups could act as electron donors. This unique property enables xB-PCN to have excellent charge generation, separation and transfer ability for the highly efficient photodegradation of CIP, reaching 87.56% of decomposition efficiency within 1 h with the apparent rate constant (0.01151 min−1) of 6.85 times that of PCN. Furthermore, the 3B-PCN maintained high degradation percentage in tap water (84.63%) and aquaculture wastewater (78.41%). The results of LC-MS and TOC showed that CIP was gradually mineralized and the degradation pathways were proposed. Based on the radical trapping experiments and ESR characterization, the reactive oxygen species involved in the degradation of CIP were checked. This work offers a promising approach for treating antibiotics polluted water based on a metal-free conjugated polymeric g-C3N4.

Photodegradation of Ciprofloxacin and Levofloxacin by Au@ZnONPs-MoS2-rGO Nanocomposites

This study aimed to investigate the photocatalytic performance of diverse zinc oxide catalysts containing gold nanoparticles (AuNPs), molybdenum disulfide (MoS2), and reduced graphene oxide (rGO) toward the degradation of the antibiotics levofloxacin (LFX) and ciprofloxacin (CFX) in aqueous solutions. The obtained results demonstrate that LFX is more resistant to degradation when compared with CFX and that the principal route of degradation under visible light is the formation of hydroxyl radicals. Photoluminescence (PL) measurements were employed to verify the inhibitory effect of electron–hole recombination when AuNPs, MoS2, and rGO are integrated into a semiconductor. The catalyst that achieved the highest percentage of CFX degradation was 1%Au@ZnONPs-3%MoS2-1%rGO, exhibiting a degradation efficiency of 96%, while the catalyst that exhibited the highest percentage of LFX degradation was 5%Au@ZnONPs-3%MoS2-1%rGO, displaying a degradation efficiency of 99.8%. A gas chromatography–mass spectrometry (GC-MS) analysis enabled the identification of reaction intermediates, facilitating the determination of a potential degradation pathway for both antibiotics. Additionally, recyclability assessments showed that the synthesized catalysts maintained stable photocatalytic efficiencies after 15 cycles, indicating that the heterostructures have the potential for further usage and may be tested with other organic contaminants as well.

Synthesis of novel Type-II MnNb2O6/g-C3N4 Mott-Schottky heterojunction photocatalyst: Excellent photocatalytic performance and degradation mechanism of fluoroquinolone-based antibiotics

Fluoroquinolone antibiotics have been encountered in aquatic environments in quantities giving rise to significant concern recently. To cope with this problem, it is necessary to design a semiconductor photocatalyst having excellent photocatalytic efficiency to eliminate the antibiotics. The heterojunction is a likely situate where the efficiency of relevant photocatalyst can be strengthened. In this study, the performance of MnNb2O6/g-C3N4 (MNO/g-CN) composites in the photocatalytic degradation of ciprofloxacin (CIP) and tetracycline-HCl (TCH) antibiotics was explored. Enhanced photocatalytic activity of MNO/g-CN was found to be owing to electron's shifting between the MNO, and g-CN sheets, which promotes the formation of photo-generated e⁻/h⁺ pairs. This shows a low-waste, high-performance material exists to eradicate CIP and TCH from wastewater. Further, the structural, photochemical and light interacted properties of the MNO/g-CN photocatalyst, prepared by solvothermal method and sonication, were described using photochemical, physiochemical and electrochemical approaches. The synthesized photocatalyst owes its particular efficiency to its methodical photo-degradation of CIP and TC using visible light. The optimum composite 15% MNO/g-CN evinced the greatest photocatalytic efficiency with CIP and TCH photo-degradation of 94.10%, and 98.50%, respectively, and degradation mechanism were investigated using LC-MS spectroscopy. The suitable photocatalytic activity is ascribed to lower the recombination's rate of e⁻/h⁺ pairs. The scavenging evaluations proved that the h+ and •O2− were two major photoactive species accomplishing the CIP and TCH photodegradation over MNO/g-CN under visible region. Our findings pave the way for the construction of efficient binary photocatalysts for antibiotic restitution.

Synthesis of neodymium ferrite incorporated graphitic carbonitride (NdFe2O4@g-C3N4) and its application in the photodegradation of ciprofloxacin and ampicillin in a water system.

Purification of antibiotic-contaminated drinking water sources is faced with limitations. Therefore, this study incorporated neodymium ferrite (NdFe2O4) in graphitic carbonitride (g-C3N4) to form NdFe2O4@g-C3N4 as a photocatalyst for removing ciprofloxacin (CIP) and ampicillin (AMP) from aqueous systems. X-ray diffraction (XRD) revealed a crystallite size of 25.15 nm for NdFe2O4 and 28.49 nm for NdFe2O4@g-C3N4. The bandgap is 2.10 and 1.98 eV for NdFe2O4 and NdFe2O4@g-C3N4, respectively. The transmission electron micrograph (TEM) images of NdFe2O4 and NdFe2O4@g-C3N4 gave an average particle size of 14.10 nm and 18.23 nm, respectively. Scanning electron micrograph (SEM) images showed heterogeneous surfaces with irregular-sized particles suggesting agglomeration at the surfaces. NdFe2O4@g-C3N4 (100.00 ± 0.00% for CIP and 96.80 ± 0.80% for AMP) exhibited better photodegradation efficiency towards CIP and AMP than NdFe2O4 (78.45 ± 0.80% for CIP and 68.25 ± 0.60% for AMP) in a process described by pseudo-first-order kinetics. NdFe2O4@g-C3N4 showed a stable regeneration capacity towards degradation of CIP and AMP with a capacity that is above 95% even at the 15th cycle of treatment. The use of NdFe2O4@g-C3N4 in this study revealed its potential as a promising photocatalyst for removing CIP and AMP in water systems.

Ultrasonic-assisted synthesis of magnetic recyclable Fe3O4/rice husk biochar based photocatalysts for ciprofloxacin photodegradation in aqueous solution.

In this work, a new facile one-spot method has been designed to fabricate a magnetic recyclable Fe3O4/rice husk biochar photocatalyst (FBP) for the removal of Ciprofloxacin (CIP) in aqueous solution. This method combines ultrasonic-assisted impregnation and precipitation, which can overcome the difficulties of long-time reactions, complex procedures, and extreme condition requirements. The successful fabrication of the Fe3O4/biochar material has been proven by a series of material characterization techniques, including X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Raman, Fourier Transform Infrared Spectroscopy (FTIR), X-ray Photoelectron Spectroscopy (XPS), and vibrating sample magnetometer (VSM). Moreover, the as-product FBP exhibited the excellent ability of photodegrading CIP and the possibility of magnetic recovery from the aqueous solution, suggesting a potential solution for removing antibiotic pollutants in environmental remediation.

Highly stable β-Bi2O3/Ag decorated nanosilica as an efficient Schottky heterojunction for ciprofloxacin photodegradation in wastewater under LED illumination

A novel mesopours SiO2/β-Bi2O3/Ag plasmonic heterojunction was first fabricated by a simple multi-step approach. The fabricated heterojunction was applied for ciprofloxacin (CIP) degradation in wastewater. The ternary SiO2/β-Bi2O3/Ag photocatalyst exhibited a wide absorption in the visible region (400–700 nm) with the assistance of the surface plasmonic resonance (SPR) behavior of Ag0 metal. Furthermore, the experimental results indicated that 96% of CIP was degraded with a TOC removal efficiency of 65% in 105 min under 140 W of light-emitting diode (LED) irradiation. The kinetics studies showed that the degradation rate of SiO2/β-Bi2O3/Ag is 0.02651 min−1, which is 3.17, 2.62, and 1.99 times higher than that of pure β-Bi2O3, SiO2/β-Bi2O3, and β-Bi2O3/Ag, respectively. The impacts of operational parameters like solution pH, CIP concentration, and SiO2/β-Bi2O3/Ag dosage were also assessed. The trapping experiments suggested that the main reactive species is the •OH radical, which can be easily generated on the valence band of β-Bi2O3. The Schottky heterojunction between β-Bi2O3 and Ag nanoparticles was well depicted based on trapping tests and characterization techniques. The stability experiments suggested that the SiO2/β-Bi2O3/Ag nanocomposite possessed high stability in five consecutive cycles and could be applied for CIP removal with acceptable photodegradation performance. Finally, it can be concluded that the nanosilica exhibited an efficient support structure, which can significantly improve the surface properties of SiO2/β-Bi2O3/Ag by inhibiting the agglomeration effects of β-Bi2O3/Ag nanoparticles as well as enhance the adsorption and stability of nanocomposite.

Construction of single tungsten/copper atom oxide supported on the surface of TiO2 for the higher activity of electrocatalytic water splitting and photodegradation of organic pollutant

Intense studies are being carried out on single atom catalysts that exhibit remarkable activity and selectivity. To enhance their catalytic abilities, one must have a thorough understanding of the properties of the single metal atom active site and its dynamics in the working state. Herein, we report single metal atom oxide (SMAO) (metal: W/Cu) anchored on TiO2-rGO nanomaterials (SMAO-ED-TiO2-rGO) by simple sonication process. It is efficient for the electrocatalytic hydrogen evolution reaction (HER), oxygen evolution reaction (OER) and photocatalytic degradation of pharmaceutical pollutant. The uniform dispersion of the tungsten/copper metal atom oxide over a TiO2-rGO materials is detected by high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). The SMAO-ED-TiO2-rGO nanocatalyst has shown impressive HER/OER activity with an overpotential of 121/295 mV at (−)10 mA cm−2 current density and the low Tafel slope of 96/60.3 mV dec−1 in 1 M KOH solution. Further, SMAO-ED-TiO2-rGO nanocatalyst was used for the photocatalytic degradation of ciprofloxacin (CF). After 60 min of UV light irradiation, the SMAO-ED-TiO2-rGO nanocatalyst efficiently photodegraded 98.5% of CF while retaining its activity for five cycles. Superoxide radicals (O2•-) are found to be the main reactive species required in the photodegradation of CF, according to scavenger study of the SMAO-ED-TiO2-rGO nanocatalyst for CF degradation.

Electrospun Sn-doped TiO2: Synthesis, structural, optical and catalytic performance as a function of Sn loading and calcination temperatures

A series of tin (Sn)-doped titania (TiO2) composites were prepared by electrospinning and then calcined at temperatures of 500 °C, 600 °C, and 700 °C. The morpho-structural and optical properties of the resulting composites were assesed by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), diffuse reflectance spectroscopy (DRS), and photoluminescence (PL) spectroscopy. In this way, the effect of the dopant amounts and calcination temperatures on the composition, morphology, band gap energy (Eg) of the prepared composites was established, as well as their photocatalytic activity towards ciprofloxacin (CIP) photodegradation. The kinetics of ciprofloxacin photodecomposition reactions was analyzed. Herein, it is reported that the nanostructured material based on ([1.5%]Sn:TiO2) sintered at 500 °C shows a remarkable photocatalytic activity with a removal efficiency of about 100% and a rate constant of 9.685 × 10−2 min−1. The photocatalytic stability of this material was evaluated by reusability tests with five cycles under identical conditions for CIP photodegradation. In-depth structural investigations were undertaken to explain this remarkable photocatalytic activity towards water decontamination.

ZIF-8 derived porous C, N co-doped ZnO modified B-g-C3N4: A Z-Scheme charge dynamics approach operative towards photocatalytic hydrogen evolution and ciprofloxacin degradation

Herein, the fabrication of a robust CNZ/BCN nanocomposite is achieved by a facile in-situ calcination of ZIF-8 along with BCN precursors. Morphologically the dodecahedral ZIF-8 farmeworks are transformed into granular CNZ nanoparticles that were densely adhered to the BCN nanosheet surface with interfacial interactions. MOF derived strategy plays significant role in reducing the optical band gap via introducing C, N into the ZnO lattice as known from UV–vis-DRS as well as XPS studies. Additionally the composite formation lead to significantly enhanced exciton anti-recombination as suggested from EIS and PL analysis. The optimal CNZ/BCN (1:1) nanohybrid exhibits enhanced photocatalytic H2 evolution rate of 7020 µmol h−1 g−1 which is nearly-two and eight folds greater than that of pristine CNZ and BCN respectively along with maximal ciprofloxacin photo-degradation rate (86.7 %). The radical trapping experiments deduced the formation of both superoxide and hydroxyl radicals that promotes the nanocomposite to follow Z-scheme charge transfer pathway during photocatalysis. Intermediates formed during CIP photo-degradation were identified by using LC-MS technique that showed ten intermediates formed through two different routes. Hence, MOF derived CNZ and BCN nanocomposite acts as a robust Z-scheme mediated photocatlyst that can be employed for varied energy and environmental purposes.

Biosynthesized silver nanoparticles using Rosary Pea seed Extract: Evaluation of Antibacterial, cytotoxic and photocatalytic activity

An effortless, economically affordable and eco-friendly green methodology was adopted to synthesize silver nanoparticles (Ag NPs) from Rosary Pea seed extract (Abrus precatorius - AP). The bio-fabricated silver nanoparticles (AP-Ag NPs) were identified by UltraViolet–visible spectrophotometer, Fourier transform infrared (FT-IR), X-ray diffraction (XRD), Scanning electron microscope (SEM), Energy dispersive x-ray analysis (EDAX), Zeta potential and Transmission electron microscope (TEM). As per FT-IR data it has been inferred that biomolecules such as carbohydrates and proteins serve a vital role as capping and reducing agents. The formation of AP-Ag NPs is evidenced by the observation of the surface plasmon resonance peak at 419 nm. XRD analysis has confirmed the crystalline and Face-centered cubic (FCC) lattice structure of AP-Ag NPs. TEM image has proved the size (20 nm) and quasi-spherical shape of AP-Ag NPs. The observed zeta potential value, −30 mV indicates the good stability of AP-Ag NPs. The Selected Area Electron Diffraction (SAED) pattern has ascertained the polycrystalline nature of AP-Ag NPs. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) examination has been utilized to assess the cytotoxicity of the synthesized AP-Ag NPs against MCF-7, and the IC50 value has been found to be 46 ± 1.5. AP-Ag NPs has displayed antibacterial action against gram-negative and gram-positive pathogens. Efficacy of AP-Ag NPs on photodegradation of Ciprofloxacin under visible light within 90 min has been performed and has found to be above 90 %. Moreover, the optimized condition of the photocatalytic degradation has also been analyzed.

Photocatalytic degradation of ciprofloxacin antibiotic in water by biosynthesized silica supported silver nanoparticles

This study reports photocatalytic degradation of ciprofloxacin (CIP) in the presence of silver nanoparticles impregnated over amorphous silica extracted from rice husk through a green approach using Melia Azedarach fruit extract. Various analyses such as X-ray diffraction analysis (XRD), Fourier-transform infrared (FTIR) spectroscopy, and field emission scanning electron microscopy (FESEM) were employed to characterize the obtained nanocomposite. Afterward, the photocatalytic activity of the nanocomposite was studied in the removal of CIP from an aqueous solution under natural sunlight irradiation. Moreover, the effect of various parameters such as solution initial pH (3–11), reaction time (30–180min), and catalyst loading (0.03–0.12 g) on degradation efficiency were studied by applying a design of experiment (DOE) methodology. The results indicated the successful synthesis and deposition of Ag nanoparticles over amorphous silica. The results of degradation experiment confirmed the acceptable performance of Ag/silica nanocomposite in photo-degradation of CIP. According to the experimental design, both catalyst loading and reaction time are highly significant; whereas the initial pH is not significant compared to other factors. Moreover, the optimal conditions were determined to be initial pH = 6.7, reaction time = 180 min, and catalyst loading of 0.12 g. By applying these optimal conditions, degradation efficiency reached to 98%. Moreover, the results of kinetic study revealed that the photo-degradation of CIP in presence of Ag/silica nanocomposite obeys a first-order kinetic model. The Ag/silica nanocomposite exhibited a high level of stability as the nanocomposites could preserve their stability after three sequential degradation cycles.

Brij 58–activated carbon assisted synthesis of Ag/Ag2O/TiO2-AC photocatalysts for efficient organic pollutants degradation

TiO2-activated carbon composites with mesoporous structure were prepared by sol-gel method using different titanium precursors (titanium tetraisopropoxide, tetraethyl orthotitanate) and surfactants (Brij 58 and activated carbon). Two different activated carbons (AC and ACP), obtained from ground coffee, were activated in different conditions with orto-phosphoric acid. Finaly the obtained supports were dopped with Ag (1%). The crystalline structure, morphology, mesoporous structure, surface composition and optical properties of Ag/Ag2O/C/P/TiO2 photocatalysts were characterized by X-ray diffraction (XRD), BET surface area measurements, scanning and transmission electron microscopy (SEM, TEM), X-ray photoelectron spectroscopy (XPS), Raman, diffuse reflectance spectroscopy (DRS) and photoluminescence (PL) techniques. A significant effect of activated carbon and titanium precursor on TiO2 crystalline phase was evidenced. Thus, XRD and TEM evidenced amorphization of TiO2 structure for samples with high phosphorus percent in activated carbon. As well, a small amount of rutile, together anatase, stood out for samples obtained from tetraethyl orthotitanate. XPS spectra revealed the presence of Ag1+, Ag0, C-C, C-O, C-P, and P-O species on the surface with significant effect on adsorption and photocatalytic degradation of Brilliant Blue FCF dye and antibiotic Ciprofloxacin. The best activity and no toxicity of the obtained water after Ciprofloxacin photodegradation was evidenced for the sample with higher P content. The obtained results highlighted that activated carbon play an outstanding role in the mechanism of dye and antibiotic photodegradation influencing both the adsorption of organic molecules and photocatalytic performances of p-n Ag2O/TiO2 heteroconjunction from composite materials.

Intensification of non-thermal plasma for aqueous Ciprofloxacin degradation: Optimization study, mechanisms, and combined plasma with photocatalysis

As it is well known that wastewater treatment is becoming a global concern, the search for advanced intensive oxidation processes with minimal waste generation for wastewater treatment remains a major challenge. In the present work, the photodegradation of Ciprofloxacin (CIP) was studied using the Dielectric-Barrier-Discharge (DBD) process. The effect of some operating parameters such as CIP initial concentration (from 1 to 6 mg/L), air flow rate (from 0 to 240 L/h) and frequency (from 350 to 600 Hz) on DBD performance in term of CIP degradation efficiency (%D) has been investigated. Here, as a major result, the CIP degradation efficiency and the mineralization yield (%M) reached >99 % and >49 %, respectively, during 60 min, under the obtained optimum experimental conditions (an initial concentration of 1 mg/L, an air flow rate of 100 L/h, a voltage of 18 kV, and a frequency of 350 Hz). It can be concluded that the DBD process exhibits an eco-friendly and great potential for aqueous CIP degradation. Moreover, the mechanisms involved in the degradation process by DBD were explained. The scavengers study revealed that °OH, HO2°and O2−° radicals were the basic reactive oxygen species (ROS) in CIP degradation process. Results show that in addition to ROS, the reactive nitrogen species (RNS) also play a key role in the CIP removal process. In order to get closer to the real conditions, DBD experiments were also carried out in other water matrices, tap water (TW) and synthetic pharmaceutical water (SW). Significant inhibition of CIP degradation (%D) and mineralization (%M) was observed in TW (%D = 76, %M = 33) and SW (%D = 60, %M = 10) with reference to the CIP degradation and mineralization in ultra-pure water (UPW) (%D ≥99, %M = 54), after 90 min irradiation. It showed that the presence of organic and inorganic molecules in TW and SW lowered the CIP degradation efficiency. Thus, the combined plasma-photocatalysis system, using luminous textile as photocatalyst, was performed for the CIP degradation in SW, in order to get closer to the real conditions, leading to >99 of %D and 64 of %M. Moreover, the use of combined DBD plasma-photocatalysis process significantly enhanced the CIP degradation performance if compared to each process considered separately. Overall, the combination of DBD and photocatalysis may be a promising technology for economical, efficient and environmentally friendly removal of pollutants in wastewater.

Highly selective photodegradation of ciprofloxacin by molecularly imprinted Fe3O4/g-C3N4

• A new MI-FC has been fabricated by hydrothermal and molecular imprinting technology. • MI-FC exhibits high selective adsorption degradation efficiency for CIP. • MI-FC possesses a stable photocatalytic activity after five recycling runs. • O 2 − and h + are active species during the photocatalytic process. A stable molecularly imprinted Fe 3 O 4 /g-C 3 N 4 (MI-FC) was fabricated using a hydrothermal method and molecular imprinting technology. The selective degradation of MI-FC was evaluated by the adsorption and photodegradation of ciprofloxacin and levofloxacin. Compared with other photocatalysts, MI-FC showed excellent selective adsorption efficiency (51.18%) and photodegradation efficiency (71.44%) for ciprofloxacin. The ciprofloxacin adsorption and degradation efficiency were higher than that of levofloxacin. These results suggest the synergistic effects of selective recognition and photocatalysis can improve photocatalytic selectivity. This study provides a method for the removal of low residue pollutants in wastewater.

Visible Light-Driven Photocatalytic Degradation of Ciprofloxacin, Ampicillin and Erythromycin by Zinc Ferrite Immobilized on Chitosan

This study investigated the synthesis of zinc ferrite immobilized on chitosan (ZnFe2O4@Chitosan) and its application in the photodegradation of ciprofloxacin (CIP), ampicillin (AMP) and erythromycin (ERY) in aqueous solution. Results from Fourier transform infrared spectroscopy (FTIR) revealed peaks suggesting its synthesis, while signals from X-ray diffraction (XRD) showed diffraction patterns confirming the synthesis of ZnFe2O4@Chitosan with a crystallite size of 35.14 nm. Scanning electron microscopy (SEM) revealed a homogeneous morphology with a surface area of 12.96 m2 g−1 from the Brunauer–Emmett–Teller (BET) analysis. The vibrating sample magnetometry (VSM) result revealed a saturation magnetization of 2.38 emu g−1. The photodegradation study of CIP, AMP and ERY showed that both photodegradation and adsorption were taking place at the same time with the percentage degradation efficiency in the order CIP (99.80 ± 0.20%) > AMP (94.50 ± 0.10%) > ERY (83.20 ± 0.20%). ZnFe2O4@Chitosan exhibited high stability with capacity > 90% even at the 15th regeneration cycle, suggesting a viable economic value of ZnFe2O4@Chitosan.

Novel 1D/3D CeO2/g-C3N4 catalysts for photodegradation of ciprofloxacin under visible light via dimensional regulation and heterostructure construction

Dimensional regulation and heterostructure building strategy are the significant means to boost the property of semiconductor photocatalysts. Herein, CeO2/g-C3N4 (CeCN) composites with 1D/3D structure were synthesized by compounding one-dimensional CeO2 nanorods and three-dimensional porous carbon nitride materials. Diverse characterization methods, BET, XRD, SEM/TEM, FT-IR, XPS and UV–vis DRS, to name a few, were conducted to reveal the surface area, micro shape, crystal structure, surface functional groups and photoconductive properties of the samples. The photocatalytic properties of catalyst were estimated by photodegradation of ciprofloxacin (CIP) under visible light irradiation. The results suggested that CeO2 nanorods with 1D structure and g-C3N4 with 3D porous structure are successfully composite into 1D/3D composites without any crystal structure and surface functional groups changed. The optimal CeCN25 exhibited brilliant photodegradation performance with 96.3% degradation efficiency within 100 min under visible light irradiation. The dimension control strategy made the material form porous structure and increases the adsorption performance of the material, while the heterostructure construction strategy formed a space electric field with efficient charge separation and transfer, which prolonged charge life. The combination of two strategies was the crucial factor for the eminent catalytic activity of photocatalysts. This work supplies thinking for the directional design and synthesis of composite catalysts with high photocatalytic activity.