Ni2P‐Modified Ta3N5 and TaON for Photocatalytic Nitrate Reduction

Wei, Lin
Adamson, Marquix
Vela, Javier
Journal Title
Journal ISSN
Volume Title
Research Projects
Organizational Units
Ames Laboratory
Organizational Unit
Organizational Unit
Journal Issue

Self‐sustaining photocatalytic NO 3 ‐ reduction systems could become ideal NO 3 ‐ removal methods. Developing an efficient, highly active photocatalyst is the key to the photocatalytic reduction of NO 3 ‐ . In this work, we present the synthesis of Ni 2 P‐modified Ta 3 N 5 (Ni 2 P/Ta 3 N 5 ), TaON (Ni 2 P/TaON), and TiO 2 (Ni 2 P/TiO 2 ). Starting with a 2 mM (28 g/mL NO 3 ‐ ‐N) aqueous solution of NO 3 ‐ , as made Ni 2 P/Ta 3 N 5 and Ni 2 P/TaON display as high as 79% and 61% NO 3 ‐ conversion under 419 nm light within 12 h, which correspond to reaction rates per gram of 196 μmol g ‐1 h ‐1 and 153 μmol g ‐1 h ‐1 , respectively, and apparent quantum yields of 3–4%. Compared to 24% NO 3 ‐ conversion in Ni 2 P/TiO 2 , Ni 2 P/Ta 3 N 5 and Ni 2 P/TaON exhibit higher activities due to the visible light active semiconductor (SC) substrates Ta 3 N 5 and TaON. We also discuss two possible electron migration pathways in Ni 2 P/semiconductor heterostructures. Our experimental results suggest one dominant electron migration pathway in these materials, namely: Photo‐generated electrons migrate from the semiconductor to co‐catalyst Ni 2 P, and upshift its Fermi level. The higher Fermi level provides greater driving force and allows NO 3 ‐ reduction to occur on the Ni 2 P surface.


This is the peer-reviewed version of the following article: Wei, Lin, Marquix Adamson, and Javier Vela. "Ni2P‐Modified Ta3N5 and TaON for Photocatalytic Nitrate Reduction." ChemNanoMat (2020), which has been published in final form at DOI: 10.1002/cnma.202000174. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving. Posted with permission.

NO3- reduction, Ni2P photocatalysis, Ta3N5, TaON, clean water