ZnO/Cu(2)O/g-C(3)N(4) heterojunctions with enhanced photocatalytic activity for removal of hazardous antibiotics

Advancements in research on the precise eradication of cancer cells through nanophotocatalytic technology

The rapid development of nanotechnology has significantly advanced the application of nanophotocatalysis in the medical field, particularly for cancer therapy. Traditional cancer treatments, such as chemotherapy and radiotherapy, often cause severe side effects, including damage to healthy tissues and the development of drug resistance. In contrast, nanophotocatalytic therapy offers a promising approach by utilizing nanomaterials that generate reactive oxygen species (ROS) under light activation, allowing for precise tumor targeting and minimizing collateral damage to surrounding tissues. This review systematically explores the latest advancements in highly efficient nanophotocatalysts for cancer treatment, focusing on their toxicological profiles, underlying mechanisms for cancer cell eradication, and potential for clinical application. Recent research shows that nanophotocatalysts, such as TiO2, In2O3, and g-C3N4 composites, along with photocatalysts with high conduction band or high valence band positions, generate ROS under light irradiation, which induces oxidative stress and leads to cancer cell apoptosis or necrosis. These ROS cause cellular damage by interacting with key biological molecules such as DNA, proteins, and lipids, triggering a cascade of biochemical reactions that ultimately result in cancer cell death. Furthermore, strategies such as S-scheme heterojunctions and oxygen vacancies (OVs) have been incorporated to enhance charge separation efficiency and light absorption, resulting in increased ROS generation, which improves photocatalytic performance for cancer cell targeting. Notably, these photocatalysts exhibit low toxicity to healthy cells, making them a safe and effective treatment modality. The review also discusses the challenges associated with photocatalytic cancer therapy, including limitations in light penetration and the need for improved biocompatibility. The findings suggest that nanophotocatalytic technology holds significant potential for precision cancer therapy, paving the way for safer and more effective treatment strategies.

Effective approach for removing antibiotic residues from wastewater using Bi2O3@C3N4 photocatalyst

This study explores the photocatalytic decomposition of antibiotic residues, including tetracycline (TCR) and amoxicillin (AMR), from wastewater using Bi2O3@C3N4 photocatalyst. The characterization findings revealed that Bi2O3@C3N4 exhibited significantly improved light absorption properties and enhanced charge separation efficiency. According to the experimental results, Bi2O3@C3N4 exhibited high degradation efficiencies of 77.6% for TCR and 83.2% for AMR in wastewater samples. It also displayed excellent reusability, with the removal efficiencies of TCR and AMR remaining at 71.3 and 78.8%, respectively, after five cycles. Additionally, the photodegradation of TCR and AMR using Bi2O3@C3N4 is suggested to follow the Z-scheme pathway. The results of this study could be utilized for removing antibiotic pollutants from wastewater, thereby reducing their impact on human health and the environment.

Zinc Chloride-Doped g-C3N4 Microtubes for Enhanced Photocatalytic Degradation of Tetracycline Hydrochloride

Morphology regulation and element doping are effective means to improving the photocatalytic performance of graphite-phase carbon nitride (g-C3N4). In this article, using melamine and zinc chloride as raw materials, a novel kind of Zn/Cl-doped hollow microtubular g-C3N4 (Zn-HT-CN) by a hydrothermal method was developed. The structure and morphology of Zn-HT-CN and reference samples were characterized by X-ray diffraction patterns (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), etc. The doping of Zn/Cl narrowed the bandgap width of the hollow microtubular g-C3N4, as well as the inhibiting recombination of photogenerated electron and holes. Compared with the pure g-C3N4 microtube, Zn-HT-CN showed excellent catalytic performance for the photodegradation of tetracycline hydrochloride (TCH) under irradiation of visible light. The photodegradation rate of TCH reached 94.41% in 40 min, which was about two times as high as that catalyzed by the pure g-C3N4 microtube. Moreover, it was also superior to the g-C3N4 microtube doped with other typical metal elements. In addition, Zn-HT-CN showed good tolerance to environmental pH, and the catalytic efficiency of the material remained at 78.78% after five cycles.

In situ synthesis of ZnO/g-C3N4 based composites for photodegradation of methylene blue under visible light

In this study, in situ-synthesized ZnO/g-C3N4 based composites were used as photocatalysts for organic pollution removal. These nanocomposites were prepared through simple calcination of a mixture of melamine and ZnO nanoparticles and underwent comprehensive evaluation of their structural, morphological, optical, and photocatalytic properties, using various analytical techniques. As the g-C3N4 content increased, the band gap decreased from 3.02 to 2.94 eV. Additionally, the reduction in photoluminescence intensity confirmed the heterojunction interface between the g-C3N4 and ZnO components. The photodegradation rate of methylene blue (MB) dye exhibited an increase, rising from 0.016 (min-1) for ZnO and 0.011 (min-1) for g-C3N4 to 0.022 (min-1) for the ZnO/g-C3N4 (10 wt%) composite. Furthermore, combining ZnO (50 wt%) with g-C3N4 led to a significant enhancement in the MB dye removal efficiency, reaching 97% compared to the ZnO/g-C3N4 (10 wt%) composite. In contrast, the removal efficiencies were 90% for pristine ZnO and 73% for g-C3N4 phases.

A focused review on photocatalytic potential of graphitic carbon nitride (g-C3N4) based metal oxide-nanostructures for effective remediation of most overused antibiotics

Researchers in the field of photocatalysis are interested in finding a solution to the problem of charge transfer and recombination in photodegradation mechanisms. The ideal photoactive catalyst would be inexpensive, environmentally friendly, easily manufactured, and highly efficient. Graphitic carbon nitride (g-C3N4) and metal oxide (MOx) based nanocomposites (g-CN/MOx) are among the photocatalysts that provide the best results in terms of charge transfer capacity, redox capabilities, and charge recombination inhibition. This article provides a comprehensive overview of the latest research on antibiotic removal from wastewater using photocatalysts based on g-C3N4 and metal oxides nanocomposites. Amoxicillin (AMX), Azithromycin (AZM), Cefixime (CFM), Ciprofloxacin (CIP), and Tetracycline (TC) are some of the common antibiotics that are the focus of this review article's examination of the photocatalytic behavior of various g-C3N4/metal oxide-based photocatalysts. A research gap demonstrates that many studies are required to use these nanocomposites for photodegradation of antibiotics. By providing a better grasp of the photocatalysis process, this review encourages scientists and researchers to develop an accurate and appropriate photocatalyst to reduce environmental risks. The main findings of this review article suggest that the cost-effective g-C3N4/MOx-based nanocomposites exhibit excellent photodegradation properties, high charge transfer, broadening light response, and charge separation. They promote enhanced charge transportation, superior electron conductivity, high redox capability, and suppressing charge recombination rate. The photodegradation mechanism involves various reactive oxygen species (ROSs), including superoxide radicals, hydroxyl radicals, and holes which promotes the photocatalysis process. The exact transportation mechanism of electrons and holes is unclear, but a rapid charge-carrier transit can significantly increase and speed up the photooxidation process.

Understanding the variations in degradation pathways and generated by-products of antibiotics in modified TiO2 and ZnO photodegradation systems: A comprehensive review

This review examines various modification techniques, including metal doping, non-metal doping, multi doping, mixed doping, and the construction of heterojunction photocatalysts, for enhancing the performance of pure TiO2 and ZnO in the photodegradation of antibiotics. The study finds that mixed and multi doping approaches are more effective in improving photodegradation performance compared to single doping. Furthermore, the selection of suitable semiconductors for constructing heterojunction photocatalysts is crucial for achieving an efficient charge carrier separation. The environmental impacts, recent research, and real application of photocatalysis process have been discussed. The review also investigates the impact of operating parameters on the degradation pathways and the generation of by-products for different antibiotics. Additionally, the toxicity of the by-products resulting from the photodegradation of antibiotics using modified ZnO and TiO2 photocatalysts is explored, revealing that these by-products may exhibit higher toxicity than the original antibiotics. Consequently, to enable the widespread implementation of photodegradation systems, researchers should focus on optimizing degradation systems to control the conversion pathways of by-products, developing innovative photoreactors, and evaluating toxicity in real wastewater matrices.

Phyto-fabricated ZnO nanoparticles for anticancer, photo-antimicrobial effect on carbapenem-resistant/sensitive Pseudomonas aeruginosa and removal of tetracycline

Alternanthera sessilis (AS) leaf extract was used to synthesize zinc oxide nanoparticles (ZnO NPs). Bioanalytical characterization techniques such as X-ray diffraction (XRD) and field emission scanning electron microscope (FESEM) confirmed the formation of crystalline ZnO NPs with average sizes of 40 nm. The AS-ZnO NPs antimicrobial activity was analyzed under dark (D) and white light (WL) conditions. The improved antimicrobial activity was observed against Escherichia coli, Staphylococcus aureus and Bacillus subtilis at the minimal inhibitory concentration (MIC) of 125 and 62.5 µg/mL under WL than the D at 125 and 250 µg/mL for E. coli, B. subtilis, and Pseudomonas aeruginosa, respectively. In contrast, the growth of P. aeruginosa and S. aureus was not completely inhibited until 1 mg/mL AS-ZnO NPs under WL and D. Similarly, AS-ZnO NPs displayed a weaker inhibitory effect against carbapenem-sensitive P. aeruginosa (CSPA) and carbapenem-resistant P. aeruginosa (CRPA) strains of PAC023, PAC041 and PAC032, PAC045 under D. Interestingly, the distinct inhibitory effect was recorded against CSPA PAC041 and CRPA PAC032 in which the bacteria growth was inhibited 99.9% at 250, 500 µg/mL under WL. The cytotoxicity results suggested AS-ZnO NPs demonstrated higher toxicity to MCF-7 breast cancer cells than the RAW264.7 macrophage cells. Further, AS-ZnO NPs exhibited higher catalytic potential against tetracycline hydrochloride (TC-H) degradation at 65.6% and 60.8% under WL than the dark at 59.35% and 48.6% within 120 min. Therefore, AS-ZnO NPs can be used to design a photo-improved antimicrobial formulation and environmental catalyst for removing TC-H from wastewater.

In situ growth of BiOBr on copper foam conductive substrate with enhanced photocatalytic performance

Photocatalysis technology based on solar-powered semiconductors is widely recognized as a promising approach for achieving eco-friendly, secure, and sustainable degradation of organic contaminants. Nevertheless, conventional photocatalysts exhibit drawbacks such as a wide bandgap, and rapid recombination of photoinduced electron/hole pairs, in addition to complicated separation and recovery procedures. In this research, we cultivated BiOBr in situ on the surface of copper foam to fabricate a functional photocatalyst (denoted as BiOBr/Cu foam), which was subsequently employed for the photodegradation of Methylene Blue. Based on photodegradation experiments, the 0.3 BiOBr/Cu foam demonstrates superior photocatalytic efficacy compared to other photocatalysts under solar light irradiation. Furthermore, its ease of separation from the solution enhances its potential for reuse. The analysis of charge transfer revealed that the copper foam functions as an effective electron scavenger within the BiOBr/Cu foam, thereby facilitating charge separation and the generation of photo-induced holes. This phenomenon contributes to a significantly enhanced production of hydroxyl radicals. This study provides a valuable perspective on the design and synthesis of photocatalysts with heightened practicality, employing a conductive substrate.