Fe-Bi dual sites regulation of BiO nanosheets to promote photocatalytic nitrogen fixation activity.

In the process of photocatalytic ammonia synthesis, efficient activation of nitrogen molecules constitutes a fundamental challenge. During the N activation, the close interdependence between the acceptance and donation of electron results in their mutual limitation, leading to high energy barrier for N activation and unsatisfactory photocatalytic performance. This work decoupled the electron acceptance and donation processes by constructing Fe-Bi dual active sites, resulting in enhancing N activation through the high electron trapping ability of Fe and strong electron donating ability of Bi. The photocatalytic nitrogen reduction efficiency of 3%Fe/BiO (118.71 μmol gh) is 5.3 times that of BiO (22.41 μmol gh). In-situ Fourier transform infrared (In situ FTIR) spectroscopy and density functional theory (DFT) calculations manifest that Fe-Bi dual active sites work together to promote nitrogen adsorption and activation, and the reaction path is more inclined toward alternate hydrogenation path. N adsorption and activation properties are optimized by heteronuclear bimetallic active sites, which offers a new way for the rational design of nitrogen-fixing photocatalysts.