Greatly boosted photocatalytic N2-to-NH3 conversion by bismuth doping in CdMoO4: Band structure engineering and N2 adsorption modification

This work enhances the photocatalytic N2 immobilization performance of CdMoO4 through Bi doping. The doped Bi element exists in the presence of Bi3+ and substitutes the position of Cd2+. The particle size of CdMoO4 is greatly decreased due to Bi doping. Additionally, it narrowed the band gap, reduced the work function, and elevated the conduction band, which endowed the Bi-doped CdMoO4 with a stronger ability in generating and separating charge carriers than CdMoO4. Density function theory (DFT) calculations further indicated that N2 has stronger adsorption at the unsaturated Mo sites of Bi-doped CdMoO4 due to the interactions between the 2π* orbital of N2 with the d orbital of Mo. The combination of these changes allows Bi-CdMoO4 to exhibit excellent photocatalytic N2-to-NH3 performance. The NH3 generation rate of optimal Bi-CdMoO4 reaches 7.2 times that of CdMoO4. This work may show some light on the preparation of novel photocatalysts for N2-to-NH3 conversion.