A new study in Scientific Reports from researchers Hailu Ashebir, Saeideh Babaee, Abebe Worku, Palesa Diale, Titus Msagati, and Jemal Fito Nure introduces a promising solution for a global public health threat. The research demonstrates how a new photocatalytic material, an N-doped TiO₂/biochar nanocomposite, successfully degraded Ciprofloxacin (CIX) from real pharmaceutical industrial wastewater. By optimizing key parameters, the team achieved remarkable degradation efficiencies, proving the material’s potential for real-world environmental applications.

The contamination of water by pharmaceutical residues, especially antibiotics like ciprofloxacin, poses significant risks to both aquatic ecosystems and human health. This is because these compounds are not easily broken down by traditional wastewater treatment methods. The persistence of CIX can lead to the development of antibiotic-resistant bacteria and its accumulation in the food chain. To combat this, researchers are exploring advanced technologies like photocatalytic degradation, which uses light to break down organic pollutants into harmless byproducts like carbon dioxide and water.

This study focused on optimizing the photocatalytic degradation of CIX using a novel N-doped TiO₂/biochar (N-doped TiO₂/BC) nanocomposite. The material was synthesized using a sol-gel technique and then tested under both UV and visible light. To find the best possible conditions for degradation, the researchers used a statistical method called Response Surface Methodology (RSM) with a Central Composite Design (CCD). The optimized conditions they identified were a contact time of 72 minutes, a pHpH is a measure of how acidic or alkaline a substance is. A pH of 7 is neutral, while lower pH values indicate acidity and higher values indicate alkalinity. Biochars are normally alkaline and can influence soil pH, often increasing it, which can be beneficial More of 6.9, a nanocomposite dosage of 2 g/L, and an initial CIX concentration of 50 mg/L. Under these optimized conditions, the nanocomposite achieved maximum degradation efficiencies of 98.9% under UV light and 96.9% under visible light in synthetic solutions.

The effectiveness of the nanocomposite is attributed to its unique properties. The researchers found that nitrogen (N) doping lowered the material’s band gap from 3.2 eV to 2.23 eV. This change allows the composite to absorb a broader range of light, including visible light, which is crucial for practical applications that rely on natural sunlight. In addition, the biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More component acts as a high-surface-area support, allowing the TiO₂ nanoparticles to disperse effectively and reducing electron-hole recombination, which in turn boosts photocatalytic activity.

A key part of this research was testing the material’s performance on actual pharmaceutical wastewater. The team applied their optimized parameters to real-world samples, achieving degradation efficiencies of 86.9% under UV and 84.3% under sunlight. Although slightly lower than the results in the lab, this still represents a significant achievement and highlights the material’s ability to overcome the complexities of real wastewater, such as the presence of other contaminants and varying ionic strengths. The nanocomposite also demonstrated good reusability, retaining over 88.9% of its efficiency after five cycles, making it a promising and stable candidate for long-term use.

The study’s findings are a major step forward in addressing the challenge of pharmaceutical pollutants in water. By creating a material that is highly efficient under natural sunlight and reusable, the researchers have provided a viable, cost-effective, and sustainable solution. This work addresses a critical gap in water treatment research and paves the way for the development of robust, scalable, and environmentally friendly systems to tackle emerging micropollutants.

Source: Ashebir, H., Babaee, S., Worku, A., Diale, P., Msagati, T., & Nure, J. F. (2025). N-doped TiO₂/prosopis juliflora biochar nanocomposites for removal of ciprofloxacin from pharmaceutical industrial wastewater. Scientific Reports, 15(1), 31795.