B-doped carbon nanotubes for enhanced adsorption of NO3- and promoted electrocatalysis on transformation nitrate into ammonia

The electrochemical nitrate reduction reaction (NO₃RR) is a promising route for green ammonia synthesis, but its complex reaction pathway makes adsorption selectivity critical. In this study, researchers introduced boron doping into nitrogen-doped carbon nanotubes (NCNTs) supported Cu₂O-Fe₃O₄ catalysts to enhance nitrate adsorption and increase local concentration near the electrode surface. The team confirmed that the B-doped carbon nanotube substrate effectively boosts NO₃RR performance with higher ammonia yield and a positive-shifted onset potential. This general doping strategy offers a new way to tune complex electrocatalytic reactions, especially those requiring high selectivity and concentration sensitivity.

A research team led by Professor Fushen Lu from Shantou University first successfully synthesized carbon nanotubes with a series of different boron contents via boron doping regulation. Various metal composite catalysts were then uniformly loaded onto the carbon nanotubes through precipitation. Among them, Cu₂O-Fe₃O₄/BNCNTs exhibited the most outstanding performance toward the nitrate reduction reaction (NO₃RR), achieving an ammonia yield as high as 95 mg h^-1 mg_cat^-1, which is superior to most reported catalysts.

Meanwhile, the team characterized the performance of a series of metals with different NO₃RR activities in the presence and absence of boron doping, verifying the universality of this strategy.

The team published their research paper in Nano Research on May 6, 2026.

“In this work, we systematically investigated the promoting effect of support materials with Lewis acidic sites on the NO₃RR. We introduced and compared the NO₃RR performance of Cu₂O-Fe₃O₄ with and without boron doping, and the results showed comprehensive enhancement of NO₃RR performance through boron doping. Furthermore, we explored different metal oxides as catalytic active sites, demonstrating the universality of this strategy,” said Professor Fushen Lu, corresponding author of the paper, Professor at Shantou University and Vice Dean of the School of Chemistry and Chemical Engineering.

The team expects this work to provide new insights for catalyst preparation, helping to achieve lower energy consumption and improved energy conversion efficiency for the NO₃RR.

“The main challenge for NO₃RR lies in promoting the adsorption and activation of NO₃^–. The introduction of Lewis acidic sites shows great potential to address this issue,” Professor Lu added.

Other contributors include Muwei Ji (lecturer), and Ce Zhou, Yaoting Huang, Chenqi Liu, Chenxi Wang, Wenjing Fang, Hong Xia, and Yibing Song from the School of Chemistry and Chemical Engineering, Shantou University.

This work was supported by Shantou Scientific Research Initiation Grant (NTF22018), Guangdong Basic and Applied Basic Research Foundation (2025A1515010343, 2023A1515010562, and 2026A1515010751), Special Fund for the Sci-tech Innovation Strategy of Guangdong Province (STKJ202209083), the Innovation Team Project of Guangdong Provincial Department of Education (2023KCXTD012).

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About Nano Research

Nano Research is a peer-reviewed, open access, international and interdisciplinary research journal, sponsored by Tsinghua University and the Chinese Chemical Society, published by Tsinghua University Press on the platform SciOpen. It publishes original high-quality research and significant review articles on all aspects of nanoscience and nanotechnology, ranging from basic aspects of the science of nanoscale materials to practical applications of such materials. After 18 years of development, it has become one of the most influential academic journals in the nano field. Nano Research has published more than 1,000 papers every year from 2022, with its cumulative count surpassing 8,000 articles. In 2025 InCites Journal Citation Reports, its 2025 IF is 9.4 (8.3, 5 years), and it continues to be the Q1 area among the four subject classifications. Nano Research Award, established by Nano Research together with TUP and Springer Nature in 2013, and Nano Research Young Innovators (NR45) Awards, established by Nano Research in 2018, have become international academic awards with global influence.