Young scholars from Xi’an Jianda University develop new composite photocatalysts to remove emerging pollutants from water

On October 16, recent developments from Xi’an University of Architecture and Technology caught our attention, particularly from their Interdisciplinary Innovation Research Institute’s Ecological Restoration Research Team. The team has made significant strides by developing a novel nitrogen-sulfur co-doped biochar-based silver phosphate composite photocatalyst. This innovative material, utilizing activated biochar as its carrier through hydrothermal reactions combined with chemical coprecipitation methods, aims to efficiently remove high concentrations of norfloxacin from water.

In recent years, the challenge of treating emerging pollutants, such as residual antibiotics in water bodies, has drawn global scholarly attention. Photocatalysis is recognized as one of the most effective and promising technologies for purifying contaminated water. However, traditional photocatalysts often suffer from rapid recombination of photogenerated charge carriers, which hinders their practical application.

To address this issue, researchers have proposed the strategy of constructing heterojunctions by combining traditional photocatalysts with carbon materials to enhance photocatalytic activity through adsorption. This approach presents new challenges in the design and development of advanced photocatalysts. Current studies indicate that doping with non-metal or heavy metal elements can enhance photocatalytic activity, but the mechanisms of cooperative enhancement through multi-element doping are still in the early stages of exploration.

The composite photocatalyst developed by the research team at Xi’an University consists of a ternary material made up of silver sulfide, silver phosphate, and activated biochar, incorporating nanosilver particles. This composite demonstrates a Z-scheme photogenerated carrier transfer mode. By co-doping nitrogen and sulfur, the team has enriched the elemental composition, surface functional groups, and defects of the photocatalyst, while also activating the mesoporous structure. Importantly, this material exhibits reusability, light stability, and resistance to interference in complex environments, offering a more cost-effective solution compared to other photocatalysts in similar studies. Furthermore, their research sheds light on the synergistic mechanisms that enhance photocatalytic activity through non-metal co-doping.

According to the researchers, this study provides fresh perspectives on the mechanisms of nitrogen-sulfur co-doping that synergistically enhance the photocatalytic properties of silver phosphate. It also generates key data on the degradation processes and new byproducts of quinolone antibiotics, paving the way for the effective application of low-cost photocatalytic technologies.

The findings, titled “Novel Z-Scheme Nitrogen-Sulfur Co-Doped Biochar-Based Silver Phosphate Composite for Efficient Removal of Norfloxacin and Synergistic Mechanism,” were published in the journal npj Clean Water, and systematically explore the removal effects of norfloxacin in simulated water environments and actual wastewater. This work, led by the young researcher Wang Tongtong from Xi’an University of Architecture and Technology, elaborates on the effects of various environmental factors, degradation processes, and pathways, revealing the mechanisms behind synergistic enhanced photocatalysis.

Under the leadership of Professor Shi Hui, the Ecological Restoration Research Team at the Interdisciplinary Innovation Research Institute has established a prominent research focus on the ecological treatment of water environments, water quality assurance and restoration, organic soil pollution remediation, and urban vegetation’s role in intercepting air particulates, adhering to their philosophy of “rooted in ecology, oriented towards engineering, integrating disciplines, and emphasizing application.”