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Abstract This study involves a novel CuO/CoFe₂O₄/MWCNTs (CCT) nanocomposite, developed by integrating cobalt ferrite (CoFe₂O₄) and copper oxide (CuO) nanoparticles onto multi-walled carbon nanotubes (MWCNTs), for the degradation of tetracycline (TC) under visible light. The photocatalyst was extensively characterized using XRD, HR-SEM, EDX, HR-TEM, UV-Vis, BET, and PL analysis. The synthesized CoFe₂O₄ and CuO nanoparticles exhibited crystallite sizes of 46.8 nm and 37.5 nm, respectively, while the CCT nanocomposite had a crystallite size of 53 nm. Microscopy confirmed a particle size of 49.2 nm for the nanocomposite, with MWCNTs measuring 15.65 nm in diameter. The band gap energy of the CCT nanocomposite was 1.6 eV, which contributed to its enhanced photocatalytic activity, as evidenced by the lower emission intensity in PL analysis. BET analysis revealed a pore volume of 0.37 cc/g and a surface area of 82.3 m²/g. Photocatalytic performance was tested across various conditions, with adjustments to nanocomposite dosages (0.1–0.5 g/L), TC concentrations (5–25 mg/L), and pH levels (2–10). Under optimized conditions (0.3 g/L CCT, 5 mg/L TC, pH 10, 120 min of visible light exposure), the CCT achieved 98.1% degradation of TC. The optimized parameters were subsequently used to assess TC degradation with individual photocatalysts: CoFe₂O₄, CuO, CT, and CCT. The enhanced photocatalytic efficiency observed can be largely attributed to the improved charge transfer dynamics and effective electron-hole separation facilitated by MWCNT doping. The reaction followed a pseudo-first-order kinetic model, with hydroxyl radicals (OH•) identified as the key species in the degradation process. Moreover, the catalyst exhibited 96% retention of its photocatalytic efficiency after five consecutive cycles, demonstrating exceptional stability and reusability. These results emphasize the CCT composite’s potential as a highly efficient and sustainable photocatalyst for the remediation of pharmaceutical pollutants in aquatic systems.

In this study, we developed a non-enzymatic photoelectrochemical sensor using a BiOBr-CuO (BiCu) electrode, which was synthesized via solvothermal method. The sensor was designed for the simultaneous detection of glucose and tetracycline. Our study revealed that the BiCu electrode exhibited superior photocurrent generation compared to the individual BiOBr and CuO electrodes, as demonstrated by cyclic voltammetry and amperometric studies. The BiCu electrode's performance has increased due to the formation of a heterojunction between CuO and BiOBr, which modifies the UV–visible DRS spectrum and generates an internal electric field that reduces the recombination of the photogenerated carriers. This enhanced the capability of the sensor to detect both glucose and tetracycline. We successfully applied the proposed photoelectrochemical sensor to detect human blood glucose level. The sensitivity and detection limit for glucose and tetracycline are 0.1342 mAmM−1cm−2, 0.014 mM and 1.7234 mAmM−1cm−2, 2.0 μM respectively. Thus, the fabricated electrode demonstrated exceptional catalytic activity, high selectivity, good reproducibility, wide linear detection range, low limit of detection,long-term stability, ease of synthesis, good stability and notable selectivity for detecting both glucose and tetracycline This suggests that the BiCu electrode has significant potential as a reliable platform for the detection of glucose and tetracycline.

This scrutiny encounters the hydrothermal approach of binary nanocomposites V2O5/TiO2 (VT). The XRD pattern substantiated the formation of the binary composites with 18 nm of the crystallite size without any extraneous impurities. Whereas, HR-SEM implies the efficient bonding and homogeneous distribution between V2O5 and TiO2 nanoparticles, which provokes high electrochemical performances. Additionally, the BET analysis exposes the specific surface area to be 251 m2 g−1 with an average pore size of 3.14 nm for the VT nanocomposite. The electrochemical performances of the binary VT nanocomposite exhibit high specific capacitance of 443.7 Fg−1 at a current density of 1 Ag−1 with an excellent cyclic retention of 90 % even after successive 5000 cycles at 5 Ag−1. Therefore, the results obtained in this study clearly demonstrates that the binary nanocomposite VT would be a favorable electrode material for the commercial energy storage applications.

In this study, a ternary nanocomposite of reduced graphene oxide/Nickel oxide@Titanium dioxide (rGO/NiO@TiO2-RNT) was synthesized via a hydrothermal technique. The X-ray diffraction (XRD) pattern revealed that the composite possessed a well-defined crystalline structure, which was essential for efficient charge transfer and electrochemical performance. High-resolution scanning electron microscope (HR-SEM) analysis found that the composite between NiO@TiO2 and rGO sheets was coupled through Van der Waals interactions, providing efficient electron/ion paths and sufficient buffer space to alleviate volume expansion. The electrochemical exploration of the prepared ternary nanocomposite exhibited a remarkable specific capacitance of 856 Fg−1 at a current density of 1 Ag−1 and revealed excellent cyclic retention of 91% even after successive 5000 cycles at 5 Ag−1. Finally, the fabricated asymmetric supercapacitor demonstrated a specific capacitance of 325 Fg−1 at a current density of 1 Ag−1, with a maximum energy and power density of 64 Wh Kg−1 and 1.2 KW kg−1, maintained stability at 83% after 5000 cycles. Therefore, the results obtained in this study demonstrated that the prepared ternary nanocomposite is a potential electrode material for next-generation energy storage applications. [ABSTRACT FROM AUTHOR]

Tetracycline (TC), a popular antibiotic for treating bacterial diseases in living things, poses a serious threat to the aquatic environment. Even though several standard techniques to remove TC antibiotics from water solutions have been tried, they have not been successful. Therefore, a catalyst works in photocatalytic degradation to use light energy to speed up the breakdown of a chemical molecule. The hydrothermally synthesized ZnFe2O4/MWCNTs composite nanocatalyst was characterized. The study found that MWCNTs could be successfully incorporated into ZnFe2O4 nanoparticles, which slowed down the rate at which charge carriers recombined after merging with MWCNTs. In a batch reactor, the catalyst’s effectiveness was then evaluated by looking at the weight ratio change of the nanocomposite, the initial concentration of TC antibiotics, the impacts of pH and the contact time. When investigating the TC degradation using ZnFe2O4 and MWCNTs as separate pure materials, the same operational conditions were used. ZnFe2O4/MWCNTs achieved a degradation efficiency of 98.3% for TC at a pH value of 7. This result was attained after a reaction duration of 120 min, TC solution concentration of 50 mg/L, nanocomposite dose of 0.6 g/L of TZ 04 and power density of 120 W/m2. The degradation rate of TC was determined utilizing the pseudo-first-order approach. It was observed that the photocatalysts retained their initial characteristics through four successive applications, exhibiting only a slight decrease in removal efficiency while maintaining an optimal balance of catalyst, TC concentration and pH. The study’s findings showed that the ZnFe2O4/MWCNTs nanocomposite was highly effective in TC degradation. It has the potential to work effectively as a catalyst for the removal and degradation of pharmaceutical waste. [ABSTRACT FROM AUTHOR]

Tetracycline (TC), a commonly used antibiotic for studying bacterial illnesses in living organisms, poses a significant risk to the aquatic environment. Despite various conventional methods having been attempted to remove TC antibiotics from water solutions, they have not proven effective. Consequently, the focus of the research is on the photocatalytic degradation of TC. According to the research, MWCNTs were successfully incorporated into NiFe 2 O 4 nanoparticles, which reduced the pace at which charge carriers recombined after joining with MWCNTs. Subsequently, the catalyst's efficacy was assessed in a batch reactor by analyzing the weight percentage change of the nanocomposite, the initial concentration of TC antibiotics, the effects of pH and contact time. The identical operational parameters were employed to investigate the degradation of TC using NiFe 2 O 4 and MWCNTs as individual pure materials. The findings indicated that the photocatalytic process using NiFe 2 O 4 /MWCNTs achieved a degradation efficiency of 95.8% for TC at a pH value of 9. This result was obtained after a reaction time of 120 minutes, the concentration of TC solution was 10 mg L -1 , with a nanocomposite dose of 0.6 g L -1 of TN 04 and 120 W m -2 . The pseudo-first-order approach was used to estimate the rate at which TC degrades. After four consecutive uses, it was observed that the photocatalysts maintained their original properties, with only a slight decrease of approximately 2.4% in the removal efficiency. The study demonstrated that the NiFe 2 O 4 /MWCNTs nanocomposite exhibited considerable efficiency in degrading TC. Due to its simple manufacture and useful recovery, it has the potential to function well as a catalyst for the removal and degradation of pharmaceutical organic contaminants., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (This journal is © The Royal Society of Chemistry.)