Construction of Frustrated Lewis Pair Sites in CeO 2 -C/BiVO 4 for Photoelectrochemical Nitrate Reduction.

Photoelectrochemical nitrate reduction reaction (PEC NIRR) could convert the harmful pollutant nitrate (NO 3 - ) to high-value-added ammonia (NH 3 ) under mild conditions. However, the catalysts are currently hindered by the low catalytic activity and slow kinetics. Here, we reported a heterostructure composed of CeO 2 and BiVO 4 , and the "frustrated Lewis pairs (FLPs)" concept was introduced for understanding the role of Lewis acids and Lewis bases on PEC NIRR. The electron density difference maps indicated that FLPs were significantly active for the adsorption and activation of NO 3 - . Furthermore, carbon (C) improved the carrier transport ability and kinetics, contributing to the NH 3 yield of 21.81 μg h -1 cm -2 . The conversion process of NO 3 - to NH 3 was tracked by 15 NO 3 - and 14 NO 3 - isotopic labeling. Therefore, this study demonstrated the potential of CeO 2 -C/BiVO 4 for efficient PEC NIRR and provided a unique mechanism for the adsorption and activation of NO 3 - over FLPs.