Efficient Photocatalytic Degradation Of Tetracycline Research Articles

Efficient photocatalytic degradation of tetracycline and its derivatives by green recyclable PAN/Bi2WO6/Cu2O nanofiber membrane

The use of tetracycline antibiotics in industry, healthcare, animal husbandry, agriculture, and aquaculture has resulted in excessive concentrations in a variety of aquatic environments. In this work, PAN/Bi2WO6/Cu2O nanofibrous membranes (PBC ENMs) with photocatalytic degradation performance were successfully prepared using electrostatic spinning technique, and the morphology of catalysts and PBC ENMs were characterised by SEM, BET and UV–Vis. The results demonstrated that the prepared nanofibrous membranes could achieve 97.05 % photocatalytic degradation of TC under visible light, and the degradation efficiencies of its derivatives, chlortetracycline (CTC) and oxytetracycline (OTC), reached 90.87 % and 85.12 %, respectively. Free radical trapping experiments and mechanistic analyses showed that·O2– is the main active factor in the degradation process. The highest degradation rate of 97.05 % was achieved at initial pH = 7.2.PBC ENMs adsorbed above 87.5 % after six cycles of the experiment. The highest degradation rate of 97.05 % was achieved at initial pH = 7.2 PBC ENMs adsorbed above 87.5 % after six cycles of the experiment. Based on the above advantages, the preparation process of PBC ENMs is simple, low-cost and has good catalytic effect, which provides a simple and efficient treatment means for the treatment of TC wastewater and has a broad application prospect.

Construction of g-C3N4/BiOCl hybrids via hydrothermal synthesis for efficient photocatalytic degradation of Tetracycline, Rhodamine B, and Nitenpyram

A photocatalysis system is widely regarded as the most renewable approach to environmental treatment since sunlight is a long-term source of energy for the planet. This study assessed the efficacy of a photocatalyst graphitic carbon nitride/bismuth oxychloride (g-C3N4/BiOCl) by using scanning electron microscopy (SEM), ultraviolet-visible diffuse reflectance spectroscopy (DRS), photo-luminance, photocurrent density, and X-ray diffraction to characterize the photocatalyst. The results showed an improvement in morphology and enhanced photodegradation of pharmaceutical residues such as Nitenpyram, Tetracycline, and Rhodamine B. For a wavelength range of 655 to 420 nm, the synthesized photocatalysts were good at the absorption of visible light. A photodegradation proficiency of 64.72% was observed with tetracycline, 48.91% nitenpyram, and 98.70% with Rhodamine B in 30 min. The g-C3N4/BiOCl displayed a significant photocatalytic activity due to high load separation and transition. This study shows that g-C3N4/BiOCl photocatalyst has been confirmed as one of the most intriguing contenders for innovative photocatalyst designs and can potentially be used in treating wastewater and the environment at large.

Construction of novel biochar/g-C3N4/BiOBr heterojunction with S-scheme mechanism for efficient photocatalytic degradation of tetracycline

In this work, a novel biochar/g-C3N4/BiOBr (BCN/BiOBr) S-scheme heterojunction was synthesized for the removal of tetracycline (TC) under visible light. The 0.75-BCN/BiOBr heterojunction exhibited a significantly higher degradation efficiency of TC in wastewater under visible light excitation, achieving about 86.5 % degradation in 72 minutes, which is 2.5 times higher than that of pure g-C3N4. Furthermore, the influence of factors such as pH, dosage of tetracycline and photocatalyst on TC degradation were investigated. Photochemical characterization experiments revealed that the enhanced degradation performance of the BCN/BiOBr heterojunction stemmed from the synergistic effects of adsorption and photocatalysis, providing more active sites to promote the photocatalytic reaction, and accelerating accelerate charge separation and light absorption ability. Meanwhile, the results from the active species indicated that h+, ·OH, and ·O2- play major roles in the degradation process. Additionally, the mechanism research revealed that the photogenerated carriers followed an S-scheme step transfer pathway at the interface of BiOBr and g-C3N4, and the two possible pathways for TC degradation. This provides guidance for improving wastewater treatment using biochar-modified high-efficiency S-scheme photocatalysts.

MOF-derived In2O3/TiO2 S-scheme heterojunction for efficient photocatalytic degradation of tetracycline

It is challenging to engineer a photocatalyst that can degrade antibiotics efficiently. We have successfully developed a series of photocatalysts by annealing In-MOF (BUT-205) with TiO2, namely (a) In2O3/TiO2-I, (b) In2O3/TiO2-II, and (c) In2O3/TiO2-III. These catalysts, particularly In2O3/TiO2-III, exhibited superior efficiency in degrading tetracycline (TC) under visible light. The enhanced photocatalytic performance of In2O3/TiO2-III can be attributed to the formed S-scheme heterojunction, which promoting the separation of electron-hole pairs. The S-scheme heterojunction was confirmed by XPS, in-situ XPS, UV–vis diffuse reflectance spectroscopy, and Mott-Schottky plot, etc. Compared to pure TiO2 and In2O3, the In2O3/TiO2-III demonstrated an 18-fold and 3-fold higher degradation rate constant (k). Various factors affecting the degradation of TC were investigated, including pollutant concentration, catalyst type, solution pH, catalyst dosage, inorganic anions, inorganic cations, and radical species. Photoluminescence (PL) and transient photocurrent density evaluate the separation rate of electron-hole pairs, and EPR experiments (active species trapping) studies confirmed •O2− and h+ as the primary entities in TC photodegradation by In2O3/TiO2-III. HPLC/MS analysis revealed the photocatalytic degradation pathway. The MOF-derived photocatalysts efficiency in TC photoreduction results from the formed S-scheme heterojunction, making it a promising candidate for environmental remediation.

Carboxymethyl-β-cyclodextrin functionalized TiO2@Fe3O4@RGO magnetic photocatalyst for efficient photocatalytic degradation of tetracycline under visible light irradiation

In this study, a novel magnetic photocatalyst, carboxymethyl-β-cyclodextrin functionalized titanium dioxide@Fe3O4@reduced graphene oxide (CMCD-TiO2@Fe3O4@RGO) was successfully fabricated by a facile hydrothermal synthesis method. Raman spectroscopy, XRD, BET, FT-IR, VGM, XPS, TGA, SEM, EDS and TEM were used to characterize the photocatalysts. The photocatalytic degradation behavior of tetracycline (TC) was investigated under 420 nm light wavelengths, and the reaction mechanism was interpreted. Furthermore, the stability and reusability of CMCD-TiO2@Fe3O4@RGO were assessed. The outcomes showed that CMCD-TiO2@Fe3O4@RGO possessed higher photocatalytic activity compared with TiO2@Fe3O4@RGO, TiO2@Fe3O4 and TiO2. Under continuous irradiation at 420 nm light for 60 minutes, CMCD-TiO2@Fe3O4@RGO achieved a TC degradation efficiency of 83.3 % at a concentration of 20 mg/L. The kinetic constant for the photocatalytic degradation of TC by CMCD-TiO2@Fe3O4@RGO was determined to be 0.459 mg L−1·min−1, which was 1.49 times higher than that of TiO2@Fe3O4. The main reactive oxygen species contributing to TC degradation were determined to be ·O2- and h+. The presence of RGO and CMCD is beneficial for the adsorption of TC on the photocatalyst. Furthermore, the transfer of photo-generated electrons from the semiconductor to the RGO suppresses electron-hole recombination and enhances carrier lifetime, thereby improving photocatalytic degradation efficiency. Remarkable recyclability and stability were observed in CMCD-TiO2@Fe3O4@RGO, with only a 10.4 % reduction in TC removal after five cycles.

Construction of functionalized In-based metal organic framework/BiOCl1−xIx Z-scheme heterojunction for efficient photocatalytic degradation of tetracycline: Performance and mechanism

The environmental implications of antibiotics have drawn widespread attention. Numerous monomer-based bismuth oxide halide catalysts have been extensively studied to remove tetracycline (TC) from aquatic environments. Integrating bismuth oxide halide composites with In-based metal organic framework (NH2-MIL-68(In)) might potentially serve as a novel strategy. By meticulously adjusting Cl and I within the composite bismuth halide oxide (B-x), a suite of purpose built heterojunctions (NMB-x) were synthesized, which were engineered to facilitate the efficient photodegradation of TC in simulated and actual aquatic environments. The incorporation of Z-scheme heterojunctions yielded a significant enhancement in photocatalytic responsiveness and charge carrier separation. Notably, NMB-0.3 demonstrated remarkable TC removal efficiency of 88.52 ± 3.05%, which is 3.74 times of B-0.3 within 90 min. The apparent quantum yield was also increased from 8.97% (B-0.3) to 19.68% (NMB-0.3). The removal of TC from natural water bodies was also assessed. Moreover, the photocatalyst concentration, assessed using response surface method, was found to show influential factors on TC removal. In addition, density functional theory (DFT) simulations were employed to identify vulnerable sites within TC. Intermediates and pathways in the photodegradation of TC have also been inferred. Furthermore, a comprehensive environmental toxicity assessment of representative intermediates demonstrated that these intermediates exhibited significantly reduced environmental toxicity compared to TC. This study provides a new approach to the design strategy of efficient and environmentally friendly MOF-based photocatalysts.

Fabrication of Ag-decorated La0.9Ag0.1FeO3 for efficient photocatalytic degradation of tetracycline under visible light with the assistance of water oxidation

The photocatalytic conversion of molecular O2 into reactive oxygen species, such as superoxide radicals (·O2-), has become the focus in the oxidative removal of organic pollutants. Nevertheless, the inefficient light absorption, limited adsorption of O2, and the fast recombination rate of photo-induced electron-hole pairs considerably impede the conversion efficiency of the photocatalysts. Herein, we report the synthesis of Ag@LAFO photocatalyst, which contains Ag nanoparticles (NPs)-decorated LAFO (Ag-substituted LaFeO3), to enhance the photodegradation efficiency of tetracycline (TC) with the assistance of water oxidation. Structural and spectroscopic analyses confirmed the successful decoration of Ag NPs on LAFO, which was prepared by substituting 10 % La with Ag. The efficiency of TC photocatalytic degradation rate of Ag@LAFO is 76.25 %, which is 6.1-fold higher than that of pure LFO (12.41 %). The trapping experiment of active radicals verified that ·O2- was crucial in the decomposition of TC molecules and was continuously supplied by the reduction of O2 molecules supported by photocatalytic water oxidation. Moreover, the Ag NPs in Ag@LAFO were found to be crucial for boosting the capture of photo-induced electrons and the activation of adsorbed O2. This study offers a new perspective on the conversion of O2 to ·O2- with the assistance of photocatalytic water oxidation for photocatalytic degradation of organic pollutants.

Preparation of colored TiO2 flower/Ti3C2 for efficient photocatalytic degradation of tetracycline

Herein, colored TiO2 flowers grown on Ti3C2 (XTFT, where X = 250 °C, 300 °C, and 350 °C representing heating temperature) are prepared as photocatalysts for degradation of tetracycline using hydrothermal method and CVD process. TiO2 has a suitable bandgap as a photocatalyst. However, in practical applications, TiO2 cannot effectively utilize visible light and the recombination of photogenerated carriers is excessively fast. The fabrication of XTFT through defect engineering compensates for the shortcomings of pure TiO2 in photocatalytic applications, following which the bandgap of TiO2 is reduced and the TiO2 surface becomes discolored and effectively responds to visible light. Ti3C2, a promising auxiliary material in the field of photocatalysis, is used as a photocatalyst in the degradation of tetracycline via defect engineering. After forming a composite with TiO2, Ti3C2 can effectively separate TiO2 photogenerated carriers to enhance the photocatalytic performance of TiO2. The degradation rate of 50 mL 50 mg/L tetracycline by 50 mg 300TFT under visible light irradiation for 30 min is 96.3 %. Compared with pure TiO2, the photocatalytic efficiency is significantly improved, thus providing a new idea for realization of highly efficient visible photocatalysis in the field of environmental pollution in future.

Internal electric field promoted NCDs/BiOBr/AgBr Z-scheme heterojunction with rich oxygen vacancies for efficient photocatalytic degradation of tetracycline and reduction of Cr (VI)

It is important to prepare efficient photocatalysts for the degradation of antibiotics and heavy metals. In this study, NCDs/BiOBr/AgBr Z-scheme heterojunction photocatalysts with excellent performance were constructed. NCDs/BiOBr/AgBr form a Z-type heterojunction system with pyrrole nitrogen-doped carbon quantum dots (NCDs) as charge transfer channels. The internal electric field formed in NCDs/BiOBr/AgBr greatly facilitated electron transfer. The more easily broken Bi-O bonds were utilized in the synthesis to introduce rich oxygen vacancies (OVs) into NCDs/BiOBr/AgBr to promote molecular oxygen activation. Meanwhile, silver nanorods were reduced in the synthesis to enhance the photodegradation performance. The photocatalytic degradation of tetracycline (TC) and reduction of Cr (VI) were enhanced by about 4 and 6 times. The factors affecting the removal effects of TC and Cr (VI) were analyzed. The catalysts were also tested to have good stability and potential for application in real wastewater. The reactive oxygen species (ROS), which play a dominant role in the photodegradation of TC and Cr (VI) by NCDs/BiOBr/AgBr, were tested, and a possible photocatalytic mechanism was proposed.

Hierarchically Porous TiO2 Photocatalyst Prepared by Additive Manufacturing and Dealloying for Highly Efficient Photocatalytic Degradation of Tetracycline

Hierarchically Porous TiO₂ Photocatalyst Prepared by Additive Manufacturing and Dealloying for Highly Efficient Photocatalytic Degradation of Tetracycline

Fabrication of 0D/1D S-scheme CoO-CuBi2O4 heterojunction for efficient photocatalytic degradation of tetracycline by activating peroxydisulfate and product risk assessment

The step-scheme (S-scheme) heterojunction has excellent redox capability, effectively degrading organic pollutants in wastewater. Combining S-scheme heterojunction with activated persulfate advanced oxidation process reasonably can further enhance the degradation of Emerging Contaminants. Herein, a novel zero-dimensional/one-dimensional (0D/1D) CoO-CuBi2O4 (CoO-CBO) photocatalyst with S-scheme heterojunction was designed by hydrothermal and solvothermal methods. The band structure and electron and hole transfer pathway of CoO-CBO were analyzed using the ex-situ and in-situ X-ray photoelectron spectroscopy (XPS), Ultraviolet and Visible Spectrophotometer (UV–Vis) and optical radiation Kelvin probe force microscope (KPFM), and the formation of S-scheme heterojunction was demonstrated. The photocatalytic activity of ·S-scheme CoO-CBO heterojunction was carried out by degrading tetracycline (TC) with activating potassium monopersulfate triple salt under visible light. Compared with pure CuBi2O4 and pure CoO, 30%CoO/CuBi2O4 catalyst exhibited the highest TC degradation performance after activating persulfate, degrading 89.5% of TC within 90 min. On the one hand, the S-scheme heterojunction formed between CoO and CBO had a high redox potential. On the other hand, the activation of persulfate by Co and Cu could accelerate redox cycles and facilitate the generation of active radicals such as SO4−, O2− and OH, promoting the separation of the photogenerated e− and h+ in the composite, enhancing the peroxydisulfate (PDS) activation performance and improving the degradation effect of TC. Then, a gradual decrease in the toxicity of the intermediates in the TC degradation process was detected by ECOCER. In all, this study provided an S-scheme CoO/CuBi2O4 heterojunction that can activate PDS to degrade TC efficiently, which provided a new idea for the study of novel pollutant degradation and environmental toxicology.

Zinc-doped C4N3/BiOBr S-scheme heterostructured hollow spheres for efficient photocatalytic degradation of tetracycline.

Photocatalytic degradation of organic pollutants in water is of great significance to the sustainable development of the environment, but encounters limited efficiency when a single compound is used. Thus, there have been enormous efforts to find novel photocatalytic heterostructured composites with high performance. In this work, a novel S-scheme heterostructure is constructed with BiOBr and Zn2+ doped C4N3 (Zn-C4N3) by a solvothermal method for efficient photodegradation of tetracycline (TC), a residual antibiotic difficult to be removed from the aquatic environment. Thanks to Zn2+-doping induced improvement in chemical affinity between Zn-C4N3 and BiOBr, well-formed Zn-C4N3/BiOBr heterostructured hollow spheres are formed. This structure can efficiently suppress fast recombination of photogenerated electron-hole pairs to enhance the photocatalytic activity of BiOBr dramatically. At a room temperature of 25 °C and neutral pH 7, the catalyst can degrade a significant portion of TC pollutants within 30 min under visible light. Also, the Zn-C4N3/BiOBr heterostructure displays good stability after recycling experiments. Free radical capture experiments and ESR tests show that ˙O2- is the main active substance for photocatalytic degradation of TC. This study provides new insights for constructing heterostructures with an intimate interface between the two phases for photocatalytic applications.

Harnessing potassium peroxymonosulfate activation of WO3/diatomite composites for efficient photocatalytic degradation of tetracycline.

The increasing prevalence of pharmaceutical contaminants in aquatic ecosystems poses profound challenges for both environmental sustainability and public health. Addressing this pressing issue requires the development of innovative, cost-effective, and efficient remediation approaches. Here we report the synthesis of WO3/diatomite composites and their photocatalytic degradation in conjunction with potassium peroxymonosulfate (PMS) activation. By leveraging the synergistic effects, we observe a remarkable degradation of tetracycline, a significant pharmaceutical contaminant, under visible light. Analytically, we have elucidated the driving factors for the enhanced performance, emphasizing the optimal amount of WO3 (10%) in the composite and PMS concentration (3 mM). Specifically, the WO3/diatomite catalyst presents a degradation rate of 80.75% tetracycline (40 mg L-1) after 180 min of visible light irradiation. Also, we elucidate the primary roles of ˙SO4 - radicals in driving the photocatalytic reaction using free radical trapping studies. Our approach not only offers a direct solution to controlling pharmaceutical contamination but also opens new possibilities for advancing the design of composite-based photocatalysts by taking advantage of nature-derived materials.

CdS QDs grown on ellipsoidal BiVO4 for efficient photocatalytic degradation of tetracycline.

Designing efficient, inexpensive, and stable photocatalysts to degrade organic pollutants and antibiotics has become an effective way for environmental remediation. In this work, we successfully performed in situ growth of CdS QDs on the surface of elliptical BiVO4 to try to show the advantage of the binary heterojuncted photocatalyst (BVO@CdS) for the photocatalytic degradation of tetracycline (TC). The In situ growth of CdS QDs can provide a large number of reactive sites and also generate a larger contact area with BiVO4. In addition, compared with mechanical composite materials, in situ growth can significantly reduce the energy barrier at the interface between BiVO4 and CdS, providing more channels for the separation and migration of photogenerated charge carriers, and further improving reaction activity. As a result, BVO@CdS-0.05 shows the best degradation efficiency, with a degradation rate of 88% after 30 min under visible light. The TC photodegradation follows a pseudo-second-order reaction with a dynamic constant of 0.472 min-1, which is 6.47 times that of pure BiVO4, 7.24 times that of pure CdS QDs and 2 times that of the mechanical composite. The degradation rate of BVO@CdS-0.05 decreases to 77.8% with a retention rate of 88.5% after four cycles, demonstrating excellent stability. Through liquid chromatography-mass spectrometry (LC-MS) analysis, two possible pathways for TC degradation are proposed. Through free radical capture experiments, electron spin resonance measurements, and photoelectrochemical comprehensive analysis, it is confirmed that BVO@CdS composites have constructed an efficient Z-scheme heterojunction via in situ growth, thereby highly enhancing the separation and transport efficiency of charge carriers.

Efficient photocatalytic degradation of tetracycline using Z-scheme GCN/Bi12O17Br2 composites under visible light: Process and mechanism

In this paper, GCN/Bi12O17Br2 photocatalysts with Z-scheme heterojunction was prepared by in-situ growth of Bi12O17Br2 nanosheets on porous cross-layer graphitic carbon nitride (GCN), which were used for efficient and stable tetracycline (TC) degradation. The construction of Z-scheme heterojunction effectively improved the separation efficiency of photogenerated carriers and promote the formation of ·O2− and·OH. In addition, ultra-thin porous GCN showed a better morphology and structure, which was conductive to exposing more active sites. The results of experiments showed that TC degradation efficiency of 20-GCN/Bi12O17Br2 photocatalysts with good stability could reach 97% under 80 min illumination. Besides, the mechanism of electron transfer was inferred by XPS, valence band and work function, and degradation products and pathways were deduced based on LC-MS. This work provides an effective method for constructing Z-scheme heterojunction between g-C3N4 and bismuth halide to improve photocatalytic degradation performance.

MOF-Derived In2O3 Microrod-Decorated MgIn2S4 Nanosheets: Z-Scheme Heterojunction for Efficient Photocatalytic Degradation of Tetracycline.

The construction of Z-scheme heterostructures using matching band semiconductors is an effective strategy for producing highly efficient photocatalysts. In this study, MgIn2S4(MIS) was grown in situ on In2O3 microrods created with an In-based MOF material (In-MIL-68) as a template to successfully establish a unique MIS-In2O3 heterojunction with a well-matched Z-scheme interface charge transfer channel. Tetracycline (TC) as a typical antibiotic was chosen as the target pollutant to evaluate the photocatalytic activity. After 120 min of visible light irradiation, the MIS-In2O3-(10:1) material had the greatest photocatalytic degradation activity of tetracycline with 96.55%, which was 2.39 and 4.26 times that of MIS and In2O3, respectively. The improved photocatalytic activity is attributed to the in situ growth of MIS on In2O3, forming a Z-scheme heterojunction at the interface, which not only increases the specific surface area, exposes the abundant active site, and improves light utilization but also facilitates the migration and separation of photogenic carriers. The photocatalytic degradation products of TC were detected by liquid chromatography-mass spectrometry (LC-MS), and a preliminary degradation pathway was proposed. Radical capture experiments and ESR analysis confirmed that the main active species were holes (h+), superoxide radicals (•O2-), and superoxide and hydroxyl radicals (•OH). Finally, combined with band position analysis, this study proposes a direct Z-scheme heterojunction mechanism to improve the photocatalytic degradation of tetracycline in MIS under visible light.

The Construction of an α-F2O3/Tubular g-C3N4 Z-Scheme Heterojunction Catalyst for the Efficient Photocatalytic Degradation of Tetracycline

Morphological engineering and semiconductor coupling show significant potential to increase the photocatalytic performance of graphite carbon nitride (g-C3N4). In this work, a unique Z-scheme heterojunction photocatalyst composed of tubular g-C3N4 (TCN) and α-F2O3 was successfully synthesized. Combining the experimental results and characterization, we extensively investigated the charge transfer mechanism of the α-F2O3/tubular g-C3N4 (FO-TCN) heterojunctions and processes in the photocatalytic degradation of tetracycline (TC). The tubular morphology provided a larger specific surface area, enhancing the light absorption area and thus improving the exposure of the active sites. Not only was the light absorption range expanded through the coupling with α-F2O3, but the charge transfer properties of the sample were also strengthened. The synergism between photocatalysis and the Fenton reaction enhanced the photocatalytic performance of the FO-TCN. Due to the previously mentioned beneficial factors, the performance of the FO-TCN photocatalyst was significantly increased; its reaction rate k value in the degradation of TC (0.0482 min−1) was 4.05 times faster than that of single g-C3N4 and it exhibited the best photocatalytic performance (95.02%) for the degradation of TC in 60 min, with an enhancement of 38.41%. Quenching experiments showed that h+ and ·O2− were the major active substances in the photocatalytic degradation process.

Facile construction of Z-scheme g-C3N4/BiOI heterojunction for improving degradation of tetracycline antibiotics

Tubular g-C3N4 derived from melamine and trithiocyanuric acid was coupled with flower-like BiOI microspheres to form Z-scheme heterojunction photocatalyst for efficient photocatalytic degradation of tetracycline (TC). The structure, morphology, and optical properties of the prepared g-C3N4/BiOI were characterized. When the mass fractions of g-C3N4 in the composites was 5 wt%, g-C3N4/BiOI exhibited the highest removal efficiency of 84.2 % within 60 min. The enhanced photocatalytic performance of g-C3N4/BiOI could be ascribed to stronger absorption in the visible region and faster charge transfer rate. Trapping experiments revealed that h+ and ·O2− radicals were the main active species. Based on the band structure and trapping experiments, the Z-scheme pathway was proposed to clarify the photocatalytic mechanism.

Organic-inorganic palladium porphyrin/NiFe-LDH hybrids with accelerated interfacial charge separation for efficient photocatalytic degradation of tetracycline and hydrogen evolution

The organic–inorganic hybrid palladium porphyrin/NiFe-LDH (PdTCPP/NiFe-LDH) was synthesized with a molar ratio of Ni/Fe = 2:1 and a mass ratio of PdTCPP/NiFe-LDH = 1:20. The experimental results display that the introduction of PdTCPP enhanced the response to visible light and promoted the acceleration of interfacial charge separation. The photocatalytic activity of PdTCPP/NiFe-LDH was evaluated by tetracycline (TC) degradation and hydrogen evolution methods under visible light illumination. The removal efficiency of TC increased from 67.2% of original NiFe-LDH to 90.6% of PdTCPP/NiFe-LDH. Furthermore, PdTCPP/NiFe-LDH also exhibited excellent photocatalytic activity in photocatalytic hydrogen evolution (88.89 mol g-1h−1), which is 2.54 times that of the original NiFe-LDH (34.95 mol g-1h−1).

Fabrication of CuO/ZnO heterojunction photocatalyst for efficient photocatalytic degradation of tetracycline and ciprofloxacin under direct sun light

The increased use of antibiotics and their discharge into the environment contaminates drinkable water, and hence, it is highly desired to develop an efficient methodology for eradicating antibiotics from water. In this investigation, sun-light driven photocatalyst CuO/ZnO heterojunction has been constructed via hydrothermal method. The chemical composition, and morphological and optical characteristics of the fabricated heterojunction catalysts were explored by various sophisticated techniques. Comprehensive studies revealed that the CuO/ZnO heterojunction photocatalyst demonstrated exceptional photocatalytic activity for decomposing tetracycline (TC) and ciprofloxacin (CIP) antibiotics in sunlight, in contrast to pristine CuO and ZnO nanoparticles. With CuO/ZnO heterojunction, 94% tetracycline and 93% ciprofloxacin antibiotics were removed within 50 min with rate constants of 0.0371 min−1 and 0.0462 min−1, respectively. Experimental studies were conducted with the help of UV–visible spectrophotometer and LC-MS technique to observe the change in concentration of antibiotics with time and to identify the intermediates formed during degradation reaction. The obtained results verified the formation of an excellent sun-light activated heterojunction for removal of toxins from wastewater.