Construction of Eu2O3/g‐C3N4 Redox Heterojunctions Containing Eu3+/Eu2+ Self‐Redox Centers for Boosted Visible‐Light Photocatalytic Activity. Issue 22 (29th May 2018) - Wang, Fangzhi
Abstract : The in‐built self‐redox couple in a heterojunction can indeed boost its photocatalytic activity. Herein, to obtain highly efficient visible‐light photocatalysis, a new Eu2 O3 /g‐C3 N4 redox heterojunction is designed and fabricated by a facile in situ growth strategy. Compared with pure g‐C3 N4, the as‐prepared Eu2 O3 /g‐C3 N4 redox heterojunction shows extremely enhanced photocatalytic performance for the decontamination of organic contaminants under visible‐light irradiation. The presence of the Eu 3+ /Eu 2+ self‐redox couple is identified by X‐ray photoelectron spectroscopy spectra analysis, before and after photoreaction. The boosted photocatalytic mechanism is explored systematically through UV/Vis diffuse reflectance spectroscopy, photoluminescence spectroscopy, and photocurrent measurements. Moreover, the radical trapping and electron paramagnetic resonance experiments reveal that · O2 – and h + are the main active species, and a small amount of · OH radical is also generated. The boosted photocatalytic performance is derived from the effective separation of photogenerated e – /h + pairs by forming a Eu2 O3 /g‐C3 N4 heterostructure with a self‐redox center. In particular, the self‐redox couple of Eu 3+ /Eu 2+ can lead to more effective separation of the photogenerated charge carriers, as well as to sustainable production of · O2 – . It is anticipated that our study could provide new insight into the development of g‐C3 N4 ‐based redox heterojunctions with high visible‐light photocatalytic performance. Abstract : Eu2 O3 /g‐C3 N4 redox heterojunctions are successfully synthesized. The boosted photocatalytic activity is derived from the formation of heterojunction structures with self‐redox centers.